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authorNicholas Noll <nbnoll@eml.cc>2021-10-15 16:18:02 -0700
committerNicholas Noll <nbnoll@eml.cc>2021-10-15 16:18:02 -0700
commitbf03074e346b004659196b6c17eee04dbffd3ac2 (patch)
tree7200db30f1ef7e3661091552932eb304bd4ce9c6
parent566d54fe549286895fdef8aa9f385686405dd290 (diff)
feat(rc): working prototype of input->compile->print loop
Diffstat
-rw-r--r--sys/cmd/rc/code.c164
-rw-r--r--sys/cmd/rc/exec.c576
-rw-r--r--sys/cmd/rc/exec.h33
-rw-r--r--sys/cmd/rc/input.c1045
-rw-r--r--sys/cmd/rc/io.c359
-rw-r--r--sys/cmd/rc/lex.c207
-rw-r--r--sys/cmd/rc/main.c47
-rw-r--r--sys/cmd/rc/parse.c1418
-rw-r--r--sys/cmd/rc/parse.h107
-rw-r--r--sys/cmd/rc/prompt.c17
-rw-r--r--sys/cmd/rc/rc.h196
-rw-r--r--sys/cmd/rc/rules.mk29
-rw-r--r--sys/cmd/rc/syntax.y104
-rw-r--r--sys/cmd/rc/sys.c139
-rw-r--r--sys/cmd/rc/tree.c79
-rw-r--r--sys/cmd/rc/util.c65
-rw-r--r--sys/cmd/rc/var.c271
-rw-r--r--sys/cmd/rc/wait.c3
18 files changed, 4859 insertions, 0 deletions
diff --git a/sys/cmd/rc/code.c b/sys/cmd/rc/code.c
new file mode 100644
index 0000000..6deed89
--- /dev/null
+++ b/sys/cmd/rc/code.c
@@ -0,0 +1,164 @@
+#include "rc.h"
+#include "parse.h"
+#include "exec.h"
+
+// -----------------------------------------------------------------------
+// types
+
+struct Interpreter
+{
+ int i, cap;
+ Code *code;
+};
+
+Code *compiled = nil;
+static struct Interpreter interpreter;
+#define emiti(x) ((void)(interpreter.i != interpreter.cap || grow()), interpreter.code[interpreter.i].i = (x), interpreter.i++)
+#define emitf(x) ((void)(interpreter.i != interpreter.cap || grow()), interpreter.code[interpreter.i].f = (x), interpreter.i++)
+#define emits(x) ((void)(interpreter.i != interpreter.cap || grow()), interpreter.code[interpreter.i].s = (x), interpreter.i++)
+
+static
+int
+grow(void)
+{
+ interpreter.cap += 100;
+ interpreter.code = erealloc(interpreter.code, sizeof(*interpreter.code)*interpreter.cap);
+ memset(interpreter.code+interpreter.cap-100, 0, 100*sizeof(*interpreter.code));
+
+ return 0;
+}
+
+static
+void
+stashaddr(int a)
+{
+ if(interpreter.i <= a || a < 0)
+ fatal("bad address %d in interpreter", a);
+
+ interpreter.code[a].i = interpreter.i;
+}
+
+static
+void
+walk(Tree *node)
+{
+ int p;
+ Tree *n;
+
+ if(!node)
+ return;
+
+ switch(node->type){
+ default:
+ print(errio, "bad type %d in interpreter walk\n", node->type);
+ break;
+
+ case '$':
+ emitf(Xmark);
+ walk(node->child[0]);
+ emitf(Xdollar);
+ break;
+
+ case '&':
+ emitf(Xasync);
+ p = emiti(0);
+ emitf(Xexit);
+ stashaddr(p);
+ break;
+
+ case ';':
+ walk(node->child[0]);
+ walk(node->child[1]);
+ break;
+
+ case '^':
+ emitf(Xmark);
+ walk(node->child[1]);
+ emitf(Xmark);
+ walk(node->child[0]);
+ emitf(Xconcatenate);
+ break;
+
+ case Targs:
+ walk(node->child[1]);
+ walk(node->child[0]);
+ break;
+
+ case Tparen: case Tblock:
+ walk(node->child[0]);
+ break;
+
+ case Tbasic:
+ emitf(Xmark);
+ walk(node->child[0]);
+ emitf(Xbasic);
+ break;
+
+ case Tword:
+ emitf(Xword);
+ emits(strdup(node->str));
+ break;
+
+ case '=':
+ for(n=node; node && node->type == '='; node = node->child[2])
+ ;
+ if(node){
+ for(node=n; node->type=='='; node = node->child[2]){
+ emitf(Xmark);
+ walk(node->child[1]);
+ emitf(Xmark);
+ walk(node->child[0]);
+ emitf(Xlocal);
+ }
+ walk(node);
+ for(node=n; node->type=='='; node = node->child[2])
+ emitf(Xunlocal);
+ }else{
+ for(node=n; node; node=node->child[2]){
+ emitf(Xmark);
+ walk(node->child[1]);
+ emitf(Xmark);
+ walk(node->child[0]);
+ emitf(Xassign);
+ }
+ }
+ node = n;
+ break;
+ }
+}
+
+// -----------------------------------------------------------------------
+// main exports
+
+void
+freecode(Code *c)
+{
+ if(--c[0].i!=0)
+ return;
+ efree(c);
+}
+
+Code *
+copycode(Code *c)
+{
+ c[0].i++;
+ return c;
+}
+
+int
+compile(Tree *node)
+{
+ flush(errio);
+ print(errio, "%t\n", node);
+
+ interpreter.i = 0;
+ emiti(1); // reference count
+
+ walk(node);
+
+ emitf(Xreturn);
+ emitf(nil);
+
+ compiled = interpreter.code;
+ return 0;
+}
diff --git a/sys/cmd/rc/exec.c b/sys/cmd/rc/exec.c
new file mode 100644
index 0000000..868b1dc
--- /dev/null
+++ b/sys/cmd/rc/exec.c
@@ -0,0 +1,576 @@
+#include "rc.h"
+#include "exec.h"
+
+#include <sys/wait.h>
+
+int yyparse(void);
+
+struct Builtin{
+ char *name;
+ void (*func)(void);
+};
+
+// -----------------------------------------------------------------------
+// globals
+
+static Word nullpath = { .str="", .link=nil };
+
+struct Builtin builtin[]={
+ {".", xdot},
+ 0,
+};
+
+/* stub out until we need */
+void Xasync(void){}
+void Xconcatenate(void){}
+void Xexit(void){}
+void Xfunc(void){}
+void Xfor(void){}
+void Xglob(void){}
+void Xjump(void){}
+void Xmatch(void){}
+void Xpipe(void){}
+void Xread(void){}
+// -----------------------------------------------------------------------
+// internal
+
+/* words and lists */
+
+static
+void
+pushword(char *str)
+{
+ if(!shell->args)
+ fatal("attempt to push on empty argument stack");
+
+ shell->args->word = makeword(str, shell->args->word);
+}
+
+static
+void
+popword(void)
+{
+ Word *w;
+ if(!shell->args)
+ fatal("tried to pop word on empty argument stack");
+
+ w = shell->args->word;
+ if(!w)
+ fatal("tried to pop word but nothing there");
+
+ shell->args->word = w->link;
+ efree(w->str);
+ efree(w);
+}
+
+static
+Word*
+copywords(Word *a, Word *tail)
+{
+ Word *v = nil, **end;
+
+ for(end=&v; a; a = a->link,end=&(*end)->link)
+ *end = makeword(a->str, nil);
+ *end = tail;
+
+ return v;
+}
+
+static
+void
+freewords(Word *w)
+{
+ Word *n;
+ while(w){
+ efree(w->str);
+ n = w->link;
+ efree(w);
+ w = n;
+ }
+}
+
+static
+void
+freelist(Word *w)
+{
+ Word *n;
+ while(w){
+ n = w->link;
+ efree(w->str);
+ efree(w);
+ w = n;
+ }
+
+}
+
+static
+void
+pushlist(void)
+{
+ List *stack = emalloc(sizeof(*stack));
+
+ stack->word = nil;
+ stack->link = shell->args;
+
+ shell->args = stack;
+}
+
+static
+void
+poplist(void)
+{
+ List *stack = shell->args;
+ if(!stack)
+ fatal("attempted to pop an empty argument stack");
+
+ freelist(stack->word);
+ shell->args = stack->link;
+ efree(stack);
+}
+
+/* system interop */
+static
+Word*
+path(char *w)
+{
+ Word *path;
+
+ if(strncmp(w, "/", 1)==0
+ || strncmp(w, "./", 2)==0
+ || strncmp(w, "../", 3)==0
+ || (path = var("path")->val)==0)
+ path=&nullpath;
+
+ return path;
+}
+
+static
+void
+xx(void)
+{
+ popword(); // "exec"
+ if(!shell->args->word){
+ Xerror("empty argument list");
+ return;
+ }
+
+ execute(shell->args->word, path(shell->args->word->str));
+ poplist();
+}
+
+static
+int
+xforkx(void)
+{
+ int n, pid;
+ char buf[ERRMAX];
+
+ switch(pid=fork()){
+ case -1:
+ return -1;
+ case 0: // child
+ clearwait();
+ pushword("exec");
+ xx();
+ exit(1);
+ /*unreachable*/
+ default:
+ addwait(pid);
+ return pid;
+ }
+}
+
+/* redirections */
+void
+pushredir(int type, int from, int to)
+{
+ Redir *r = emalloc(sizeof(*r));
+
+ r->type = type;
+ r->from = from;
+ r->to = to;
+ r->link = shell->redir;
+
+ shell->redir = r;
+}
+
+/* byte code */
+static
+void
+run(Code *c, int pc, Var *local)
+{
+ Thread *new = emalloc(sizeof(*new));
+
+ new->code.i = pc;
+ new->code.exe = copycode(c);
+ new->args = nil;
+ new->local = local;
+ new->cmd.path = nil;
+ new->cmd.io = nil;
+ new->flag.eof = 0;
+ new->line = 1;
+ new->link = shell;
+
+ shell = new;
+}
+
+// -----------------------------------------------------------------------
+// exported builtins
+
+// XXX: find a better place for these
+Word*
+makeword(char *str, Word *link)
+{
+ Word *w = emalloc(sizeof(*w));
+
+ w->str = strdup(str);
+ w->link = link;
+
+ return w;
+}
+
+void
+freeword(Word *word)
+{
+ Word *n;
+
+ while(word){
+ efree(word->str);
+ n = word->link;
+ efree(word);
+ word = n;
+ }
+}
+
+int
+count(Word *w)
+{
+ int n;
+ for(n = 0; w; n++)
+ w = w->link;
+ return n;
+}
+
+// -----------------------------------------------------------------------
+// builtins
+
+static Code dotcmd[14] =
+{
+ [0] = {.i = 1},
+ [1] = {.f = Xmark},
+ [2] = {.f = Xword},
+ [3] = {.s = "0"},
+ [4] = {.f = Xlocal},
+ [5] = {.f = Xmark},
+ [6] = {.f = Xword},
+ [7] = {.s = "*"},
+ [8] = {.f = Xlocal},
+ [9] = {.f = Xreadcmd},
+ [10] = {.f = Xunlocal},
+ [11] = {.f = Xunlocal},
+ [12] = {.f = Xreturn},
+};
+
+void
+xdot(void)
+{
+ Word *p;
+ List *argv;
+ char *base;
+ int fd, iflag = 0;
+ Thread *old;
+ char file[512];
+
+ old = shell;
+ popword();
+#if 0
+ if(old->args->word && strcmp(old->args->word->str, "-i")==0){
+ iflag = 1;
+ popword();
+ }
+#endif
+ /* get input file */
+ if(!old->args->word){
+ Xerror("usage: . [-i] file [arg ...]\n");
+ return;
+ }
+
+ base = strdup(old->args->word->str);
+ popword();
+ for(fd=-1, p=path(base); p ; p = p->link){
+ strcpy(file, p->str);
+
+ if(file[0])
+ strcat(file, "/");
+ strcat(file, base);
+
+ if((fd = open(file, 0))>=0)
+ break;
+ }
+
+ if(fd<0){
+ print(errio, "%s: ", base);
+ //setstatus("can't open");
+ Xerror(".: can't open\n");
+ return;
+ }
+ /* set up for a new command loop */
+ run(dotcmd, 1, nil);
+ pushredir(Rclose, fd, 0);
+
+ shell->cmd.path = base;
+ shell->cmd.io = openfd(fd);
+
+ /* push $* value */
+ pushlist();
+ shell->args->word = old->args->word;
+
+ /* free caller's copy of $* */
+ argv = old->args;
+ old->args = argv->link;
+ efree(argv);
+
+ /* push $0 value */
+ pushlist();
+ pushword(base);
+ //ndot++;
+}
+
+void
+xboot(int argc, char *argv[])
+{
+ int i;
+ Code bootstrap[32];
+ char num[12];
+
+ i = 0;
+ bootstrap[i++].i = 1;
+ bootstrap[i++].f = Xmark;
+ bootstrap[i++].f = Xword;
+ bootstrap[i++].s="*";
+ bootstrap[i++].f = Xassign;
+ bootstrap[i++].f = Xmark;
+ bootstrap[i++].f = Xmark;
+ bootstrap[i++].f = Xword;
+ bootstrap[i++].s="*";
+ bootstrap[i++].f = Xdollar;
+ bootstrap[i++].f = Xword;
+ bootstrap[i++].s = "/dev/stdin";
+ bootstrap[i++].f = Xword;
+ bootstrap[i++].s=".";
+ bootstrap[i++].f = Xbasic;
+ bootstrap[i++].f = Xexit;
+ bootstrap[i].i = 0;
+
+ run(bootstrap, 1, nil);
+ pushlist(); // prime bootstrap argv
+
+ argv0 = strdup(argv[0]);
+ for(i = argc-1; i > 0; --i)
+ pushword(argv[i]);
+
+ /* interpreter loop */
+ for(;;){
+ shell->code.i++;
+ (*shell->code.exe[shell->code.i-1].f)();
+ }
+}
+
+// -----------------------------------------------------------------------
+// exported interpreter bytecode
+
+void
+Xmark(void)
+{
+ pushlist();
+}
+
+void
+Xerror(char *msg)
+{
+ print(errio, "rc: %s", msg);
+ flush(errio);
+ while(!shell->flag.i)
+ Xreturn();
+}
+
+void
+Xreturn(void)
+{
+ Thread *run = shell;
+
+ printf("returning\n");
+
+ while(run->args)
+ poplist();
+ freecode(run->code.exe);
+
+ shell = run->link;
+ efree(run);
+ if(!shell)
+ exit(0);
+}
+
+void
+Xword(void)
+{
+ pushword(shell->code.exe[shell->code.i++].s);
+}
+
+void
+Xdollar(void)
+{
+ int n;
+ char *s, *t;
+ Word *a, *star;
+
+ if(count(shell->args->word)!=1){
+ Xerror("variable name not singleton!\n");
+ return;
+ }
+ s = shell->args->word->str;
+ // deglob(s);
+ n = 0;
+
+ for(t = s;'0'<=*t && *t<='9';t++)
+ n = n*10+*t-'0';
+
+ a = shell->args->link->word;
+
+ if(n==0 || *t)
+ a = copywords(var(s)->val, a);
+ else{
+ star = var("*")->val;
+ if(star && 1<=n && n<=count(star)){
+ while(--n)
+ star = star->link;
+
+ a = makeword(star->str, a);
+ }
+ }
+
+ poplist();
+ shell->args->word = a;
+}
+
+void
+Xassign(void)
+{
+ Var *v;
+
+ if(count(shell->args->word)!=1){
+ Xerror("variable name not singleton!\n");
+ return;
+ }
+ //deglob(runq->argv->words->word);
+ v = var(shell->args->word->str);
+ poplist();
+
+ //globlist();
+ freewords(v->val);
+ v->val = shell->args->word;
+ v->new = 1;
+ if(v->update)
+ v->update(v);
+
+ shell->args->word = nil;
+ poplist();
+}
+
+
+void
+Xreadcmd(void)
+{
+ Thread *root;
+ Word *prompt;
+
+ flush(errio);
+ root = shell;
+
+ if(yyparse()){
+ exit(1);
+ }else{
+ --root->code.i; /* re-execute Xreadcmd after codebuf runs */
+ run(compiled, 1, root->local);
+ }
+
+ freeparsetree();
+}
+
+void
+Xlocal(void)
+{
+ if(count(shell->args->word)!=1){
+ Xerror("variable name must be singleton\n");
+ return;
+ }
+ //deglob(shell->args->word->str);
+
+ shell->local = makevar(strdup(shell->args->word->str), shell->local);
+ shell->local->val = copywords(shell->args->link->word, nil);
+ shell->local->new = 1;
+
+ poplist();
+ poplist();
+}
+
+void
+Xunlocal(void)
+{
+ Var *v = shell->local, *hide;
+ if(!v)
+ fatal("Xunlocal: no locals!", 0);
+
+ printf("unlocal\n");
+
+ shell->local = v->link;
+ hide = var(v->name);
+ hide->new = 1;
+
+ efree(v->name);
+ freewords(v->val);
+ efree(v);
+}
+
+void
+Xbasic(void)
+{
+ Var *v;
+ Word *arg;
+ int pid, status;
+ struct Builtin *b;
+
+ arg = shell->args->word;
+ if(!arg){
+ Xerror("empty argument list\n");
+ return;
+ }
+ print(errio, "recieved arg: %v\n", arg); // for debugging
+ flush(errio);
+
+ v = var(arg->str);
+ if(v->func){
+ // xfunc(v);
+ return;
+ }
+ // see if it matches a builtin
+ for(b = builtin; b->name; b++){
+ if(strcmp(b->name, arg->str)==0){
+ b->func();
+ return;
+ }
+ }
+
+ // run the external command
+ if((pid = xforkx()) < 0) {
+ Xerror("try again");
+ return;
+ }
+
+ poplist();
+ do{
+ waitpid(pid, &status, 0);
+ } while(!WIFEXITED(status) && !WIFSIGNALED(status));
+
+ printf("done waiting\n");
+}
diff --git a/sys/cmd/rc/exec.h b/sys/cmd/rc/exec.h
new file mode 100644
index 0000000..ef826fb
--- /dev/null
+++ b/sys/cmd/rc/exec.h
@@ -0,0 +1,33 @@
+#pragma once
+
+/*
+ * opcode routines
+ * Arguments on stack (...)
+ * Arguments in line [...]
+ * Code in line with jump around {...}
+ */
+
+void Xasync(void);
+void Xconcatenate(void);
+void Xdollar(void);
+void Xexit(void);
+void Xfunc(void);
+void Xfor(void);
+void Xglob(void);
+void Xjump(void);
+void Xmark(void);
+void Xmatch(void);
+void Xpipe(void);
+void Xread(void);
+void Xreturn(void);
+void Xlocal(void);
+void Xreadcmd(void);
+void Xunlocal(void);
+void Xassign(void);
+void Xbasic(void); // Xbasic(args) run command and wait for result
+void Xerror(char*);
+void Xword(void);
+
+/* builtin commands */
+void xdot(void);
+void xboot(int argc, char *argv[]);
diff --git a/sys/cmd/rc/input.c b/sys/cmd/rc/input.c
new file mode 100644
index 0000000..cf05382
--- /dev/null
+++ b/sys/cmd/rc/input.c
@@ -0,0 +1,1045 @@
+#include "rc.h"
+#include <termios.h>
+#include <sys/ioctl.h>
+
+struct Mode {
+ ushort raw : 1;
+ ushort multiline : 1;
+ ushort mask : 1;
+ ushort defer : 1;
+ struct {
+ ushort on : 1;
+ ushort insert : 1;
+ } vi ;
+};
+
+static struct Mode mode;
+static struct termios originalterm;
+
+/*
+ * The structure represents the state during line editing.
+ * We pass this state to functions implementing specific editing
+ * functionalities
+ */
+struct TerminalState
+{
+ int ifd; /* Terminal stdin file descriptor. */
+ int ofd; /* Terminal stdout file descriptor. */
+ char *buf; /* Edited line buffer. */
+ uintptr buflen; /* Edited line buffer size. */
+ char *prompt; /* Prompt to display. */
+ uintptr plen; /* Prompt length. */
+ uintptr pos; /* Current cursor position. */
+ uintptr oldpos; /* Previous refresh cursor position. */
+ uintptr len; /* Current edited line length. */
+ uintptr cols; /* Number of columns in terminal. */
+ uintptr maxrows; /* Maximum num of rows used so far (multiline mode) */
+ int history_index; /* The history index we are currently editing. */
+};
+
+enum
+{
+ KeyNil = 0, /* nil */
+ KeyCtrlA = 1, /* Ctrl+a */
+ KeyCtrlB = 2, /* Ctrl-b */
+ KeyCtrlC = 3, /* Ctrl-c */
+ KeyCtrlD = 4, /* Ctrl-d */
+ KeyCtrlE = 5, /* Ctrl-e */
+ KeyCtrlF = 6, /* Ctrl-f */
+ KeyCtrlH = 8, /* Ctrl-h */
+ KeyTab = 9, /* Tab */
+ KeyCtrlK = 11, /* Ctrl+k */
+ KeyCtrlL = 12, /* Ctrl+l */
+ KeyEnter = 13, /* Enter */
+ KeyCtrlN = 14, /* Ctrl-n */
+ KeyCtrlP = 16, /* Ctrl-p */
+ KeyCtrlT = 20, /* Ctrl-t */
+ KeyCtrlU = 21, /* Ctrl+u */
+ KeyCtrlW = 23, /* Ctrl+w */
+ KeyEsc = 27, /* Escape */
+ KeyBackspace = 127 /* Backspace */
+};
+
+
+
+static void doatexit(void);
+
+static
+void
+normalcursor(int fd)
+{
+ write(fd,"\e[2 q",5);
+}
+
+static
+void
+insertcursor(int fd)
+{
+ write(fd,"\e[6 q",5);
+}
+
+/* Raw mode: 1960 magic shit. */
+static
+int
+enterraw(int fd)
+{
+ struct termios raw;
+
+ if(!isatty(0))
+ goto fatal;
+
+ if(!mode.defer) {
+ atexit(doatexit);
+ mode.defer = 1;
+ }
+ if(tcgetattr(fd,&originalterm) == -1)
+ goto fatal;
+
+ raw = originalterm; /* modify the original mode */
+ /* input modes: no break, no CR to NL, no parity check, no strip char,
+ * no start/stop output control. */
+ raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
+ /* output modes - disable post processing */
+ raw.c_oflag &= ~(OPOST);
+ /* control modes - set 8 bit chars */
+ raw.c_cflag |= (CS8);
+ /* local modes - choing off, canonical off, no extended functions,
+ * no signal chars (^Z,^C) */
+ raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+ /* control chars - set return condition: min number of bytes and timer.
+ * We want read to return every single byte, without timeout. */
+ raw.c_cc[VMIN] = 1; raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
+
+ /* put terminal in raw mode after flushing */
+ if (tcsetattr(fd,TCSAFLUSH,&raw) < 0) goto fatal;
+ mode.raw = 1;
+ return 1;
+
+fatal:
+ errno = ENOTTY;
+ return 0;
+}
+
+static
+void
+exitraw(int fd)
+{
+ /* Don't even check the return value as it's too late. */
+ if(mode.raw && tcsetattr(fd,TCSAFLUSH,&originalterm) != -1)
+ mode.raw = 0;
+}
+
+/* Use the ESC [6n escape sequence to query the horizontal cursor position
+ * and return it. On error -1 is returned, on success the position of the
+ * cursor. */
+static
+int
+cursorposition(int ifd, int ofd)
+{
+ char buf[32];
+ int cols, rows;
+ unsigned int i = 0;
+
+ /* Report cursor location */
+ if(write(ofd, "\x1b[6n", 4) != 4)
+ return -1;
+
+ /* Read the response: ESC [ rows ; cols R */
+ while(i < sizeof(buf)-1) {
+ if(read(ifd,buf+i,1) != 1)
+ break;
+ if(buf[i] == 'R')
+ break;
+ i++;
+ }
+ buf[i] = '\0';
+
+ /* Parse it. */
+ if(buf[0] != KeyEsc || buf[1] != '[')
+ return -1;
+ if(sscanf(buf+2,"%d;%d",&rows,&cols) != 2)
+ return -1;
+
+ return cols;
+}
+
+/* Try to get the number of columns in the current terminal, or assume 80
+ * if it fails. */
+static
+int
+columns(int ifd, int ofd)
+{
+ struct winsize ws;
+
+ if(ioctl(1, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0){
+ /* ioctl() failed. Try to query the terminal itself. */
+ int start, cols;
+
+ /* Get the initial position so we can restore it later. */
+ start = cursorposition(ifd,ofd);
+ if(start == -1)
+ goto failed;
+
+ /* Go to right margin and get position. */
+ if(write(ofd,"\x1b[999C",6) != 6)
+ goto failed;
+ cols = cursorposition(ifd,ofd);
+ if(cols == -1)
+ goto failed;
+
+ /* Restore position. */
+ if(cols > start){
+ char esc[32];
+ snprintf(esc,32,"\x1b[%dD",cols-start);
+ if(write(ofd,esc,strlen(esc)) == -1)
+ ;
+ }
+ return cols;
+ }else
+ return ws.ws_col;
+
+failed:
+ return 80;
+}
+
+static
+void
+clear(void)
+{
+ if(write(1,"\x1b[H\x1b[2J",7) <= 0)
+ ;
+}
+
+/* Beep, used for completion when there is nothing to complete or when all
+ * the choices were already shown. */
+static
+void
+beep(void)
+{
+ fprintf(stderr, "\x7");
+ fflush(stderr);
+}
+
+/* =========================== Line editing ================================= */
+
+/* We define a very simple "append buffer" structure, that is an heap
+ * allocated string where we can append to. This is useful in order to
+ * write all the escape sequences in a buffer and flush them to the standard
+ * output in a single call, to avoid flickering effects. */
+struct Buffer {
+ int len;
+ char *b;
+};
+
+static
+void
+initbuffer(struct Buffer *ab)
+{
+ ab->b = nil;
+ ab->len = 0;
+}
+
+static
+void
+append(struct Buffer *ab, const char *s, int len)
+{
+ char *new = realloc(ab->b,ab->len+len);
+
+ if (new == nil) return;
+ memcpy(new+ab->len,s,len);
+ ab->b = new;
+ ab->len += len;
+}
+
+static
+void
+freebuffer(struct Buffer *ab)
+{
+ free(ab->b);
+}
+
+/* Single line low level line refresh.
+ *
+ * Rewrite the currently edited line accordingly to the buffer content,
+ * cursor position, and number of columns of the terminal. */
+static
+void
+refreshsingleline(struct TerminalState *term)
+{
+ char esc[64];
+ struct Buffer ab;
+
+ uintptr plen = term->plen;
+ int fd = term->ofd;
+ char *buf = term->buf;
+ uintptr len = term->len;
+ uintptr pos = term->pos;
+
+ while((plen+pos) >= term->cols) {
+ buf++;
+ len--;
+ pos--;
+ }
+ while(plen+len > term->cols)
+ len--;
+
+ // TODO: do we need so much malloc pressure?
+ initbuffer(&ab);
+
+ /* move cursor to left edge */
+ snprintf(esc,64,"\r");
+ append(&ab,"\r",1);
+
+ /* write the prompt and the current buffer content */
+ append(&ab,term->prompt,strlen(term->prompt));
+#if 0
+ if(mode.vi.on){
+ if(mode.vi.insert)
+ append(&ab,"[I]",3);
+ else
+ append(&ab,"[N]",3);
+ }
+ append(&ab,">",1);
+#endif
+ if(mode.mask == 1)
+ while(len--)
+ append(&ab,"*",1);
+ else
+ append(&ab,buf,len);
+
+
+ snprintf(esc,64,"\x1b[0K"); // erase to right
+ append(&ab,esc,strlen(esc));
+
+ snprintf(esc,64,"\r\x1b[%dC", (int)(pos+plen)); // move cursor to original position
+ append(&ab,esc,strlen(esc));
+
+ if(write(fd,ab.b,ab.len) == -1) /* Can't recover from write error. */
+ ;
+
+ freebuffer(&ab);
+}
+
+/* Multi line low level line refresh.
+ *
+ * Rewrite the currently edited line accordingly to the buffer content,
+ * cursor position, and number of columns of the terminal. */
+static
+void
+refreshmultilines(struct TerminalState *term)
+{
+ char esc[64];
+ int plen = term->plen;
+ int rows = (plen+term->len+term->cols-1)/term->cols; /* rows used by current buf. */
+ int rpos = (plen+term->oldpos+term->cols)/term->cols; /* cursor relative row. */
+ int rpos2; /* rpos after refresh. */
+ int col; /* colum position, zero-based. */
+ int i;
+ int old_rows = term->maxrows;
+ int fd = term->ofd, j;
+ struct Buffer ab;
+
+ /* Update maxrows if needed. */
+ if(rows > (int)term->maxrows)
+ term->maxrows = rows;
+
+ /* First step: clear all the lines used before. To do so start by
+ * going to the last row. */
+ initbuffer(&ab);
+ if(old_rows-rpos > 0){
+ snprintf(esc,64,"\x1b[%dB", old_rows-rpos);
+ append(&ab,esc,strlen(esc));
+ }
+
+ /* Now for every row clear it, go up. */
+ for(j = 0; j < old_rows-1; j++){
+ snprintf(esc,64,"\r\x1b[0K\x1b[1A");
+ append(&ab,esc,strlen(esc));
+ }
+
+ /* clean the top line. */
+ snprintf(esc,64,"\r\x1b[0K");
+ append(&ab,esc,strlen(esc));
+
+ /* Write the prompt and the current buffer content */
+ append(&ab,term->prompt,strlen(term->prompt));
+ if(mode.mask == 1){
+ for(i = 0; i < term->len; i++) append(&ab,"*",1);
+ }else
+ append(&ab,term->buf,term->len);
+
+ /* If we are at the very end of the screen with our prompt, we need to
+ * emit a newline and move the prompt to the first column. */
+ if(term->pos && term->pos == term->len && (term->pos+plen) % term->cols == 0) {
+ append(&ab,"\n",1);
+ snprintf(esc,64,"\r");
+ append(&ab,esc,strlen(esc));
+ rows++;
+ if(rows > (int)term->maxrows)
+ term->maxrows = rows;
+ }
+
+ /* Move cursor to right position. */
+ rpos2 = (plen+term->pos+term->cols)/term->cols; /* current cursor relative row. */
+
+ /* Go up till we reach the expected positon. */
+ if(rows-rpos2 > 0){
+ snprintf(esc,64,"\x1b[%dA", rows-rpos2);
+ append(&ab,esc,strlen(esc));
+ }
+
+ /* Set column. */
+ col = (plen+(int)term->pos) % (int)term->cols;
+ if(col)
+ snprintf(esc,64,"\r\x1b[%dC", col);
+ else
+ snprintf(esc,64,"\r");
+ append(&ab,esc,strlen(esc));
+
+ term->oldpos = term->pos;
+
+ if(write(fd,ab.b,ab.len) == -1) /* Can't recover from write error. */
+ ;
+
+ freebuffer(&ab);
+}
+
+/* Calls the two low level functions refreshSingleLine() or
+ * refreshMultiLine() according to the selected mode. */
+static
+void
+refreshline(struct TerminalState *term)
+{
+ if(mode.multiline)
+ refreshmultilines(term);
+ else
+ refreshsingleline(term);
+}
+
+/* insert the character 'c' at cursor current position.
+ * on error writing to the terminal -1 is returned, otherwise 0. */
+int
+insert(struct TerminalState *term, char c)
+{
+ char d;
+ if(term->len < term->buflen){
+ if(term->len == term->pos){
+ term->buf[term->pos] = c;
+ term->pos++;
+ term->len++;
+ term->buf[term->len] = '\0';
+ if((!mode.multiline && term->plen+term->len < term->cols)){
+ d = (mode.mask==1) ? '*' : c;
+ if(write(term->ofd,&d,1) == -1)
+ return 0;
+ } else
+ refreshline(term);
+ }else{
+ memmove(term->buf+term->pos+1,term->buf+term->pos,term->len-term->pos);
+ term->buf[term->pos] = c;
+ term->len++;
+ term->pos++;
+ term->buf[term->len] = '\0';
+ refreshline(term);
+ }
+ }
+ return 1;
+}
+
+/* move cursor to the left n boxes */
+static
+void
+moveleft(struct TerminalState *term, int n)
+{
+ if(term->pos > n){
+ term->pos -= n;
+ refreshline(term);
+ }else if(term->pos){
+ term->pos = 0;
+ refreshline(term);
+ }
+}
+
+/* move cursor to the right n boxes */
+static
+void
+moveright(struct TerminalState *term, int n)
+{
+ if(term->pos < term->len-n){
+ term->pos += n;
+ refreshline(term);
+ }else if(term->pos != term->len){
+ term->pos = term->len;
+ refreshline(term);
+ }
+}
+
+/* Move cursor to the start of the line. */
+static
+void
+movehome(struct TerminalState *term) {
+ if(term->pos != 0){
+ term->pos = 0;
+ refreshline(term);
+ }
+}
+
+/* move cursor to the end of the line. */
+static
+void
+moveend(struct TerminalState *term)
+{
+ if(term->pos != term->len){
+ term->pos = term->len;
+ refreshline(term);
+ }
+}
+
+/* Substitute the currently edited line with the next or previous history
+ * entry as specified by 'dir'. */
+void
+movehistory(struct TerminalState *term, int dir)
+{
+}
+
+/* delete the character at the right of the cursor without altering the cursor
+ * position. basically this is what happens with the "Delete" keyboard key. */
+void
+delete(struct TerminalState *term)
+{
+ if(term->len > 0 && term->pos < term->len){
+ memmove(term->buf+term->pos,term->buf+term->pos+1,term->len-term->pos-1);
+ term->len--;
+ term->buf[term->len] = '\0';
+ refreshline(term);
+ }
+}
+
+/* backspace implementation. */
+static
+void
+backspace(struct TerminalState *term)
+{
+ if(term->pos > 0 && term->len > 0){
+ memmove(term->buf+term->pos-1,term->buf+term->pos,term->len-term->pos);
+ term->pos--;
+ term->len--;
+ term->buf[term->len] = '\0';
+ refreshline(term);
+ }
+}
+
+#define ITERATE_BACK_UNTIL(CONDITION) \
+ uintptr d, x = term->pos; \
+ char *it = term->buf + x; \
+ \
+ while(n-- > 0 && it > term->buf){ \
+ while(it > term->buf && CONDITION(it[-1])) \
+ --it; \
+ } \
+ \
+ return it; \
+
+static
+int
+prevword(struct TerminalState *term, int n)
+{
+ char *it = term->buf + term->pos;
+
+ while(n-- > 0 && it > term->buf){
+ /* consume any leading space chars */
+ while(isspace(it[-1]) && --it >= term->buf)
+ ;
+
+ /* consume word chars */
+ while(it > term->buf && (isalnum(it[-1]) || it[-1] == '_'))
+ --it;
+ }
+
+ return it-term->buf;
+}
+
+static
+int
+nextword(struct TerminalState *term, int n)
+{
+ char *it = term->buf + term->pos;
+ char *end = term->buf + term->len;
+
+ while(n-- > 0 && it < end){
+ /* consume any leading word chars */
+ while(it < end && (isalnum(*it) || *it == '_'))
+ ++it;
+ /* consume any space chars */
+ while(isspace(*it) && it < end)
+ ++it;
+ }
+
+ return it-term->buf;
+}
+
+static
+void
+deleteprevword(struct TerminalState *term)
+{
+ uintptr old_pos = term->pos;
+ uintptr diff;
+
+ while(term->pos > 0 && term->buf[term->pos-1] == ' ')
+ term->pos--;
+ while(term->pos > 0 && term->buf[term->pos-1] != ' ')
+ term->pos--;
+
+ diff = old_pos - term->pos;
+ memmove(term->buf+term->pos,term->buf+old_pos,term->len-old_pos+1);
+
+ term->len -= diff;
+
+ refreshline(term);
+}
+
+static
+void
+normalmode(int fd)
+{
+ mode.vi.insert = 0;
+ normalcursor(fd);
+}
+
+static
+void
+insertmode(int fd)
+{
+ mode.vi.insert = 1;
+ insertcursor(fd);
+}
+
+static
+int
+vi(struct TerminalState *term, char c)
+{
+ int n = 1;
+
+action:
+ switch(c){
+ /* # of repeats */
+ case '1': case '2': case '3':
+ case '4': case '5': case '6':
+ case '7': case '8': case '9':
+ n = 0;
+ while('0' <= c && c <= '9'){
+ n = 10*n + (c-'0');
+ if(read(term->ifd, &c, 1)<1)
+ return -1;
+ }
+ goto action;
+
+ /* movements */
+ case 'l':
+ moveright(term, n);
+ break;
+
+ case 'h':
+ moveleft(term, n);
+ break;
+
+ case '0':
+ movehome(term);
+ break;
+
+ case '$':
+ moveend(term);
+ break;
+
+ case 'b':
+ term->pos = prevword(term,n);
+ refreshline(term);
+ break;
+
+ case 'w':
+ term->pos = nextword(term,n);
+ refreshline(term);
+ break;
+
+ case 'a':
+ if(term->pos < term->len){
+ term->pos++;
+ refreshline(term);
+ }
+ goto insertmode;
+
+ case 'A':
+ moveend(term);
+ goto insertmode;
+
+ case 'I':
+ movehome(term);
+ goto insertmode;
+
+ case 'i': insertmode:
+ insertmode(term->ofd);
+ break;
+
+ case 'C':
+ insertmode(term->ofd);
+ /* fallthough */
+ case 'D':
+ term->len = term->pos;
+ term->buf[term->pos] = 0;
+ refreshline(term);
+ break;
+
+ case 'd':
+ if(read(term->ifd,&c,1))
+ break;
+ switch(c){
+ default:
+ beep();
+ normalmode(term->ofd);
+ break;
+ }
+
+ default:
+ beep();
+ break;
+ }
+
+ return 0;
+}
+
+
+/* This function is the core of the line editing capability of linenoise.
+ * It expects 'fd' to be already in "raw mode" so that every key pressed
+ * will be returned ASAP to read().
+ *
+ * The resulting string is put into 'buf' when the user type enter, or
+ * when ctrl+d is typed.
+ *
+ * The function returns the length of the current buffer. */
+static
+int
+interact(int ifd, int ofd, char *buf, uintptr len, char *prompt)
+{
+ char c;
+ int n;
+ char esc[3];
+
+ struct TerminalState term;
+ /*
+ * populate the state that we pass to functions implementing
+ * specific editing functionalities
+ */
+ term.ifd = ifd;
+ term.ofd = ofd;
+ term.buf = buf;
+ term.buflen = len;
+ term.prompt = prompt;
+ term.plen = strlen(prompt);
+ term.oldpos = term.pos = 0;
+ term.len = 0;
+ term.cols = columns(ifd, ofd);
+ term.maxrows = 0;
+ term.history_index = 0;
+
+ /* Buffer starts empty. */
+ term.buf[0] = '\0';
+ term.buflen--; /* Make sure there is always space for the nulterm */
+
+ if(write(term.ofd,prompt,term.plen) == -1)
+ return -1;
+
+ for(;;){
+ n = read(term.ifd,&c,1);
+ if(n <= 0)
+ return term.len;
+
+ switch(c){
+ case KeyEnter:
+ if(mode.multiline)
+ moveend(&term);
+ return (int)term.len;
+
+ case KeyCtrlC:
+ errno = EAGAIN;
+ return -1;
+
+ case KeyBackspace:
+ case KeyCtrlH:
+ backspace(&term);
+ break;
+
+ case KeyCtrlD:
+ if(term.len > 0)
+ delete(&term);
+ break;
+
+ case KeyCtrlT:
+ if(term.pos > 0 && term.pos < term.len){
+ int aux = buf[term.pos-1];
+ buf[term.pos-1] = buf[term.pos];
+ buf[term.pos] = aux;
+ if (term.pos != term.len-1) term.pos++;
+ refreshline(&term);
+ }
+ break;
+
+ case KeyCtrlB:
+ moveleft(&term, 1);
+ break;
+
+ case KeyCtrlF: /* ctrl-f */
+ moveright(&term, 1);
+ break;
+
+ case KeyCtrlP: /* ctrl-p */
+ /* TODO next history */
+ break;
+
+ case KeyCtrlN: /* ctrl-n */
+ /* TODO prev history */
+ break;
+
+ case KeyEsc: /* escape sequence */
+ /*
+ * try to read two bytes representing the escape sequence.
+ * if we read less than 2 and we are in vi mode, interpret as command
+ * NOTE: we could do a timed read here
+ */
+ switch(read(term.ifd,esc,2)){
+ case 0:
+ if(mode.vi.on){
+ if(mode.vi.insert){
+ normalmode(term.ofd);
+ if(term.pos > 0){
+ --term.pos;
+ refreshline(&term);
+ }
+ continue;
+ }
+ }
+ case 1:
+ if(mode.vi.on){
+ if(mode.vi.insert){
+ normalmode(term.ofd);
+ if(vi(&term,esc[0]) < 0)
+ return -1;
+ continue;
+ }
+ }
+ default: // 2
+ ;
+ }
+
+ /* ESC [ sequences. */
+ if(esc[0] == '['){
+ if(0 <= esc[1] && esc[1] <= '9'){
+ /* extended escape, read additional byte. */
+ if(read(term.ifd,esc+2,1) == -1)
+ break;
+
+ if(esc[2] == '~'){
+ switch(esc[1]){
+ case '3': /* delete key. */
+ delete(&term);
+ break;
+ }
+ }
+ }else{
+ switch(esc[1]) {
+ case 'A': /* up */
+ movehistory(&term, 1);
+ break;
+ case 'B': /* down */
+ movehistory(&term, 0);
+ break;
+ case 'C': /* right */
+ moveright(&term, 1);
+ break;
+ case 'D': /* left */
+ moveleft(&term, 1);
+ break;
+ case 'H': /* home */
+ movehome(&term);
+ break;
+ case 'F': /* end*/
+ moveend(&term);
+ break;
+ }
+ }
+ }
+ /* ESC O sequences. */
+ else if(esc[0] == 'O'){
+ switch(esc[1]) {
+ case 'H': /* home */
+ movehome(&term);
+ break;
+ case 'F': /* end*/
+ moveend(&term);
+ break;
+ }
+ }
+
+ break;
+
+ default:
+ if(mode.vi.on && !mode.vi.insert){
+ if(vi(&term,c) < 0)
+ return -1;
+ }else if(!insert(&term,c))
+ return -1;
+ break;
+
+ case KeyCtrlU: /* Ctrl+u, delete the whole line. */
+ buf[0] = '\0';
+ term.pos = term.len = 0;
+ refreshline(&term);
+ break;
+
+ case KeyCtrlK: /* Ctrl+k, delete from current to end of line. */
+ buf[term.pos] = '\0';
+ term.len = term.pos;
+ refreshline(&term);
+ break;
+
+ case KeyCtrlA: /* Ctrl+a, go to the start of the line */
+ movehome(&term);
+ break;
+
+ case KeyCtrlE: /* ctrl+e, go to the end of the line */
+ moveend(&term);
+ break;
+
+ case KeyCtrlL: /* ctrl+term, clear screen */
+ clear();
+ refreshline(&term);
+ break;
+
+ case KeyCtrlW: /* ctrl+w, delete previous word */
+ deleteprevword(&term);
+ break;
+ }
+ }
+ return term.len;
+}
+
+/*
+ * this special mode is used by linenoise in order to print scan codes
+ * on screen for debugging / development purposes. It is implemented
+ * by the linenoise_example program using the --keycodes option.
+ */
+void
+printkeycode(void)
+{
+ int n;
+ char c, quit[4];
+
+ printf("entering debugging mode. printing key codes.\n"
+ "press keys to see scan codes. type 'quit' at any time to exit.\n");
+
+ if(!enterraw(0))
+ return;
+
+ memset(quit,' ',4);
+
+ for(;;){
+ n = read(0,&c,1);
+ if(n <= 0)
+ continue;
+ memmove(quit,quit+1,sizeof(quit)-1); // shift string to left
+ quit[arrlen(quit)-1] = c; /* Insert current char on the right. */
+
+ if(memcmp(quit,"quit",sizeof(quit)) == 0)
+ break;
+
+ printf("'%c' %02x (%d) (type quit to exit)\n", isprint(c) ? c : '?', (int)c, (int)c);
+ printf("\r"); /* go to left edge manually, we are in raw mode. */
+ fflush(stdout);
+ }
+ exitraw(0);
+}
+
+/*
+ * This function calls the line editing function edit() using
+ * the stdin set in raw mode
+ */
+static
+int
+raw(char *buf, uintptr len, char *prompt)
+{
+ int n;
+
+ if(!len){
+ errno = EINVAL;
+ return -1;
+ }
+
+ // XXX: should we not hardcode stdin and stdout fd?
+ if(!enterraw(0)) return -1;
+ n = interact(0, 1, buf, len, prompt);
+ exitraw(0);
+
+ return n;
+}
+
+/*
+ * called when readline() is called with the standard
+ * input file descriptor not attached to a TTY. For example when the
+ * program is called in pipe or with a file redirected to its standard input
+ * in this case, we want to be able to return the line regardless of its length
+ */
+static
+int
+notty(void)
+{
+ int c;
+
+ for(;;){
+ c = fgetc(stdin);
+ put(&shell->cmd.io, c);
+ }
+}
+
+void
+enablevi(void)
+{
+ mode.vi.on = 1;
+ insertmode(1);
+}
+
+/*
+ * The high level function that is the main API.
+ * This function checks if the terminal has basic capabilities and later
+ * either calls the line editing function or uses dummy fgets() so that
+ * you will be able to type something even in the most desperate of the
+ * conditions.
+ */
+int
+readline(char *prompt)
+{
+ int n;
+
+ // reset the command buffer
+ shell->cmd.io->e = shell->cmd.io->b = shell->cmd.io->buf;
+
+ if(!isatty(0))
+ return notty();
+
+ if((n = raw(shell->cmd.io->e, shell->cmd.io->cap-1, prompt)) == -1)
+ return 0;
+ shell->cmd.io->e += n;
+
+ /* insert a newline character at the end */
+ put(&shell->cmd.io, '\n');
+ printf("\n");
+
+ return 1;
+}
+
+/* At exit we'll try to fix the terminal to the initial conditions. */
+static
+void
+doatexit(void)
+{
+ exitraw(0);
+ normalcursor(1);
+}
diff --git a/sys/cmd/rc/io.c b/sys/cmd/rc/io.c
new file mode 100644
index 0000000..7f2d869
--- /dev/null
+++ b/sys/cmd/rc/io.c
@@ -0,0 +1,359 @@
+#include "rc.h"
+#include "parse.h"
+
+#define CAP0 512
+
+Io*
+openfd(int fd)
+{
+ Io *io = emalloc(sizeof(*io) + CAP0);
+
+ io->fd = fd;
+ io->cap = CAP0;
+ io->b = io->e = io->buf;
+ io->s = nil;
+
+ return io;
+}
+
+Io*
+openstr(void)
+{
+ char *s;
+ Io *io = emalloc(sizeof(*io) + CAP0);
+
+ io->fd = -1;
+ io->cap = CAP0;
+ io->b = io->s = emalloc(101);
+ io->e = io->b+100;
+
+ for(s = io->b; s<=io->e; s++)
+ *s=0;
+
+ return io;
+}
+
+#if 0
+/*
+ * open a corebuffer to read. EOF occurs after reading len characters from buf
+ */
+
+Io*
+opencore(char *s, int len)
+{
+ Io *io = emalloc(sizeof(*io));
+ char *buf = emalloc(len);
+ io->fd = -1 /*open("/dev/null", 0)*/;
+ io->b = io->s = buf;
+ io->e = buf+len;
+ memcpy(buf, s, len);
+
+ return io;
+}
+#endif
+
+void
+iorewind(Io *io)
+{
+ if(io->fd==-1)
+ io->b = io->s;
+ else{
+ io->b = io->e = io->buf;
+ lseek(io->fd, 0L, 0);
+ }
+}
+
+void
+terminate(Io *io)
+{
+ if(io->fd>=0)
+ close(io->fd);
+ if(io->s)
+ efree(io->s);
+
+ efree((char *)io);
+}
+
+static
+int
+refill(Io *io)
+{
+ int n;
+
+ if(io->fd==-1 || (n = read(io->fd, io->buf, io->cap))<=0)
+ return EOF;
+
+ io->b = io->buf;
+ io->e = io->buf+n;
+
+ return *io->b++&0xff;
+}
+
+
+void
+flush(Io *io)
+{
+ int n;
+ char *s;
+
+ if(io->s){
+ n = io->e-io->s;
+ io->s = realloc(io->s, n+101);
+ if(io->s==0)
+ panicf("Can't realloc %d bytes in flush!", n+101);
+ io->b = io->s+n;
+ io->e = io->b+100;
+ for(s = io->b;s<=io->e;s++) *s='\0';
+ }else{
+ n = io->b-io->buf;
+ if(n && write(io->fd, io->buf, n) < 0)
+ write(3, "write error\n", 12);
+ io->b = io->buf;
+ io->e = io->buf + io->cap;
+ }
+}
+
+
+static
+void
+printchar(Io *io, int c)
+{
+ if(io->b==io->e)
+ flush(io);
+
+ *io->b++=c;
+}
+
+void
+printquote(Io *io, char *s)
+{
+ printchar(io, '\'');
+ for(;*s;s++)
+ if(*s=='\'')
+ print(io, "''");
+ else printchar(io, *s);
+ printchar(io, '\'');
+}
+
+void
+printstr(Io *io, char *s)
+{
+ if(s==0)
+ s="(null)";
+ while(*s) printchar(io, *s++);
+}
+
+void
+printword(Io *io, char *s)
+{
+ char *t;
+
+ for(t = s;*t;t++)
+ if(!iswordchar(*t))
+ break;
+
+ if(t==s || *t)
+ printquote(io, s);
+ else
+ printstr(io, s);
+}
+
+void
+printptr(Io *io, void *v)
+{
+ int n;
+ uintptr p;
+
+ p = (uintptr)v;
+ if(sizeof(uintptr) == sizeof(uvlong) && p>>32)
+ for(n = 60;n>=32;n-=4) printchar(io, "0123456789ABCDEF"[(p>>n)&0xF]);
+
+ for(n = 28;n>=0;n-=4) printchar(io, "0123456789ABCDEF"[(p>>n)&0xF]);
+}
+
+static
+void
+printint(Io *io, int n)
+{
+ if(n<0){
+ if(n!=INT_MIN){
+ printchar(io, '-');
+ printint(io, -n);
+ return;
+ }
+ /* n is two's complement minimum integer */
+ n = -(INT_MIN+1);
+ printchar(io, '-');
+ printint(io, n/10);
+ printchar(io, n%10+'1');
+ return;
+ }
+ if(n>9)
+ printint(io, n/10);
+ printchar(io, n%10+'0');
+}
+
+static
+void
+printoct(Io *io, unsigned n)
+{
+ if(n>7)
+ printoct(io, n>>3);
+ printchar(io, (n&7)+'0');
+}
+
+static
+void
+printval(Io *io, Word *a)
+{
+ if(a){
+ while(a->link && a->link->str){
+ printword(io, a->str);
+ printchar(io, ' ');
+ a = a->link;
+ }
+ printword(io, a->str);
+ }
+}
+
+static
+void
+printtree(Io *io, Tree *t)
+{
+ if(!t)
+ return;
+
+ switch(t->type){
+ case Tword:
+ print(io,"{%s}",t->str);
+ break;
+
+ case Tbasic:
+ print(io, ">%t", t->child[0]);
+ break;
+
+ case Targs:
+ if(!t->child[0])
+ print(io, "%t", t->child[1]);
+ else if(!t->child[1])
+ print(io, "%t", t->child[0]);
+ else
+ print(io, "[%t %t]", t->child[0], t->child[1]);
+ break;
+
+ case ';':
+ if(t->child[0]){
+ if(t->child[1])
+ print(io, ";[%t %t]", t->child[0], t->child[1]);
+ else
+ print(io, "%t", t->child[0]);
+ }else
+ print(io, "%t", t->child[1]);
+ break;
+
+ case '&':
+ print(io, "&(%t)", t->child[0]);
+ break;
+
+ default:
+ print(io, "bad(%d)[%p %p %p]", t->type, t->child[0], t->child[1], t->child[2]);
+ }
+}
+
+// -----------------------------------------------------------------------
+// exports
+
+/* readers */
+int
+get(Io *io)
+{
+ if(io->b==io->e)
+ return refill(io);
+
+ return *io->b++ & 0xFF;
+}
+
+/* writers */
+int
+put(Io **iop, char c)
+{
+ int nb, ne, nc;
+ Io *io = *iop;
+ char *e = io->b + io->cap;
+
+ if(io->e == e){
+ nb = io->b - io->buf;
+ ne = io->e - io->buf;
+ nc = 2*io->cap;
+
+ if(!(io = erealloc(io, sizeof(*io)+nc)))
+ return 0;
+
+ io->b = io->buf + nb;
+ io->e = io->buf + ne;
+ io->cap = nc;
+
+ *iop = io;
+ }
+
+ *io->e++ = c;
+ return 1;
+}
+
+/* printers */
+static int pfmtnest;
+
+void
+print(Io *io, char *fmt, ...)
+{
+ va_list args;
+ char err[ERRMAX];
+
+ va_start(args, fmt);
+ pfmtnest++;
+
+ for(;*fmt;fmt++)
+ if(*fmt!='%')
+ printchar(io, *fmt);
+ else
+ switch(*++fmt){
+ case '\0':
+ va_end(args);
+ return;
+ case 'c':
+ printchar(io, va_arg(args, int));
+ break;
+ case 'd':
+ printint(io, va_arg(args, int));
+ break;
+ case 'o':
+ printoct(io, va_arg(args, unsigned));
+ break;
+ case 'p':
+ printptr(io, va_arg(args, void*));
+ break;
+ case 'Q':
+ printquote(io, va_arg(args, char *));
+ break;
+ case 'q':
+ printword(io, va_arg(args, char *));
+ break;
+ case 's':
+ printstr(io, va_arg(args, char *));
+ break;
+ case 't':
+ printtree(io, va_arg(args, struct Tree *));
+ break;
+ case 'v':
+ printval(io, va_arg(args, struct Word *));
+ break;
+ default:
+ printchar(io, *fmt);
+ break;
+ }
+
+ va_end(args);
+
+ if(--pfmtnest==0)
+ flush(io);
+}
diff --git a/sys/cmd/rc/lex.c b/sys/cmd/rc/lex.c
new file mode 100644
index 0000000..ec9e94d
--- /dev/null
+++ b/sys/cmd/rc/lex.c
@@ -0,0 +1,207 @@
+#include "rc.h"
+#include "parse.h"
+
+static int advance(void);
+// -----------------------------------------------------------------------
+// lexer
+
+struct Lexer
+{
+ int c[2];
+ ushort doprompt;
+ char buf[BUFSIZ];
+};
+
+static struct Lexer lexer = { .c={0, EOF}, .doprompt=1 };
+
+void
+yyerror(char *msg)
+{
+ print(errio, "\nrc: ");
+
+ if(lexer.buf[0] && lexer.buf[0]!='\n')
+ print(errio, "@ %q: ", lexer.buf);
+
+ print(errio, "%s\n", msg);
+ flush(errio);
+
+ while(lexer.c[0] !='\n' && lexer.c[0] != EOF)
+ advance();
+}
+
+int
+readc(void)
+{
+ int c;
+ static int peek = EOF;
+
+ if(peek!=EOF){
+ c = peek;
+ peek = EOF;
+ return c;
+ }
+ if(shell->flag.eof)
+ return EOF;
+
+ if(!prompt(&lexer.doprompt))
+ exit(1); // XXX: hack for signal handling right now...
+
+ c = get(shell->cmd.io);
+
+ lexer.doprompt = lexer.doprompt || c=='\n' || c==EOF;
+
+ if(c==EOF)
+ shell->flag.eof = 1;
+
+ return c;
+}
+
+static
+int
+peekc(void)
+{
+ if(lexer.c[1] == EOF)
+ lexer.c[1] = readc();
+
+ return lexer.c[1];
+}
+
+static
+int
+advance(void)
+{
+ int c = peekc();
+ lexer.c[0] = lexer.c[1], lexer.c[1] = EOF;
+
+ return c;
+}
+
+static
+void
+skipws(void)
+{
+ int c;
+ for(;;){
+ c = peekc();
+ if(c== ' ' || c == '\t')
+ advance();
+ else
+ return;
+ }
+}
+
+static
+void
+skipnl(void)
+{
+ int c;
+ for(;;){
+ c = peekc();
+ if(c== ' ' || c == '\t' || c == '\n')
+ advance();
+ else
+ return;
+ }
+}
+
+static
+int
+nextis(int c)
+{
+ if(peekc()==c){
+ advance();
+ return 1;
+ }
+ return 0;
+}
+
+static
+char *
+putbyte(char *buf, int c)
+{
+ if(!buf)
+ return buf;
+
+ if(buf == arrend(lexer.buf)){
+ fatal("lexer: out of buffer space");
+ return nil;
+ }
+ *buf++ = c;
+ return buf;
+}
+
+#define onebyte(c) ((c&0x80)==0x00)
+#define twobyte(c) ((c&0xe0)==0xc0)
+#define threebyte(c) ((c&0xf0)==0xe0)
+#define fourbyte(c) ((c&0xf8)==0xf0)
+
+static
+char *
+putrune(char *buf, int c)
+{
+ buf = putbyte(buf, c);
+ if(onebyte(c))
+ return buf;
+ if(twobyte(c))
+ return putbyte(buf,c);
+ if(threebyte(c)){
+ buf = putbyte(buf,c);
+ return putbyte(buf,c);
+ }
+ if(fourbyte(c)){
+ buf = putbyte(buf,c);
+ buf = putbyte(buf,c);
+ return putbyte(buf,c);
+ }
+ fatal("malformed utf8 stream");
+
+ return nil;
+}
+
+// -----------------------------------------------------------------------
+// exported functions
+
+int
+iswordchar(int c)
+{
+ return !strchr("\n \t#;&|^$=`'{}()<>", c) && c!=EOF;
+}
+
+int
+yylex(void)
+{
+ int c;
+ Tree *node;
+ char *w = lexer.buf;
+
+ yylval.tree = nil;
+
+ skipws();
+ switch(c=advance()){
+ case EOF:
+ return EOF;
+ case '&':
+ lexer.buf[0] = '&';
+ lexer.buf[1] = 0;
+ return '&';
+
+ default:
+ ;
+ }
+ if(!iswordchar(c))
+ return c;
+
+ for(;;){
+ w = putrune(w, c);
+ c = peekc();
+ if(!iswordchar(c))
+ break;
+ advance();
+ }
+ w[0] = 0;
+
+ node = token(Tword, lexer.buf);
+
+ yylval.tree = node;
+ return node->type;
+}
diff --git a/sys/cmd/rc/main.c b/sys/cmd/rc/main.c
new file mode 100644
index 0000000..46a4e0f
--- /dev/null
+++ b/sys/cmd/rc/main.c
@@ -0,0 +1,47 @@
+#include "rc.h"
+#include "parse.h"
+#include "exec.h"
+
+int rcpid;
+Io *errio = nil;
+Thread *shell = nil;
+
+int
+main(int argc, char *argv[])
+{
+ int i;
+ Code bootstrap[32];
+ char num[12];
+
+ errio = openfd(2);
+
+ initenv();
+ initpath();
+
+ itoa(num, rcpid = getpid());
+ setvar("pid", makeword(num, nil));
+
+ xboot(argc, argv);
+#if 0
+ Thread root = {
+ .cmd = {
+ .path = "<nil>",
+ .io = openfd(0),
+ },
+ .line = 0,
+ .flag = {
+ .i = 1,
+ .eof = 0,
+ },
+ };
+
+ shell = &root;
+ errio = openfd(2);
+#if 1
+ while(!yyparse())
+ ;
+#else
+ printkeycode()
+#endif
+#endif
+}
diff --git a/sys/cmd/rc/parse.c b/sys/cmd/rc/parse.c
new file mode 100644
index 0000000..e2e4afa
--- /dev/null
+++ b/sys/cmd/rc/parse.c
@@ -0,0 +1,1418 @@
+/* A Bison parser, made by GNU Bison 3.8.2. */
+
+/* Bison implementation for Yacc-like parsers in C
+
+ Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2021 Free Software Foundation,
+ Inc.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* As a special exception, you may create a larger work that contains
+ part or all of the Bison parser skeleton and distribute that work
+ under terms of your choice, so long as that work isn't itself a
+ parser generator using the skeleton or a modified version thereof
+ as a parser skeleton. Alternatively, if you modify or redistribute
+ the parser skeleton itself, you may (at your option) remove this
+ special exception, which will cause the skeleton and the resulting
+ Bison output files to be licensed under the GNU General Public
+ License without this special exception.
+
+ This special exception was added by the Free Software Foundation in
+ version 2.2 of Bison. */
+
+/* C LALR(1) parser skeleton written by Richard Stallman, by
+ simplifying the original so-called "semantic" parser. */
+
+/* DO NOT RELY ON FEATURES THAT ARE NOT DOCUMENTED in the manual,
+ especially those whose name start with YY_ or yy_. They are
+ private implementation details that can be changed or removed. */
+
+/* All symbols defined below should begin with yy or YY, to avoid
+ infringing on user name space. This should be done even for local
+ variables, as they might otherwise be expanded by user macros.
+ There are some unavoidable exceptions within include files to
+ define necessary library symbols; they are noted "INFRINGES ON
+ USER NAME SPACE" below. */
+
+/* Identify Bison output, and Bison version. */
+#define YYBISON 30802
+
+/* Bison version string. */
+#define YYBISON_VERSION "3.8.2"
+
+/* Skeleton name. */
+#define YYSKELETON_NAME "yacc.c"
+
+/* Pure parsers. */
+#define YYPURE 0
+
+/* Push parsers. */
+#define YYPUSH 0
+
+/* Pull parsers. */
+#define YYPULL 1
+
+
+
+
+/* First part of user prologue. */
+#line 5 "sys/cmd/rc/syntax.y"
+
+ #include "rc.h"
+
+ int yylex(void);
+ void yyerror(char *);
+
+#line 78 "sys/cmd/rc/parse.c"
+
+# ifndef YY_CAST
+# ifdef __cplusplus
+# define YY_CAST(Type, Val) static_cast<Type> (Val)
+# define YY_REINTERPRET_CAST(Type, Val) reinterpret_cast<Type> (Val)
+# else
+# define YY_CAST(Type, Val) ((Type) (Val))
+# define YY_REINTERPRET_CAST(Type, Val) ((Type) (Val))
+# endif
+# endif
+# ifndef YY_NULLPTR
+# if defined __cplusplus
+# if 201103L <= __cplusplus
+# define YY_NULLPTR nullptr
+# else
+# define YY_NULLPTR 0
+# endif
+# else
+# define YY_NULLPTR ((void*)0)
+# endif
+# endif
+
+#include "parse.h"
+/* Symbol kind. */
+enum yysymbol_kind_t
+{
+ YYSYMBOL_YYEMPTY = -2,
+ YYSYMBOL_YYEOF = 0, /* "end of file" */
+ YYSYMBOL_YYerror = 1, /* error */
+ YYSYMBOL_YYUNDEF = 2, /* "invalid token" */
+ YYSYMBOL_Tword = 3, /* Tword */
+ YYSYMBOL_Tif = 4, /* Tif */
+ YYSYMBOL_Telse = 5, /* Telse */
+ YYSYMBOL_Tbang = 6, /* Tbang */
+ YYSYMBOL_Targs = 7, /* Targs */
+ YYSYMBOL_Tbasic = 8, /* Tbasic */
+ YYSYMBOL_Tparen = 9, /* Tparen */
+ YYSYMBOL_Tblock = 10, /* Tblock */
+ YYSYMBOL_Twhile = 11, /* Twhile */
+ YYSYMBOL_12_n_ = 12, /* '\n' */
+ YYSYMBOL_13_ = 13, /* '$' */
+ YYSYMBOL_14_ = 14, /* '(' */
+ YYSYMBOL_15_ = 15, /* ')' */
+ YYSYMBOL_16_ = 16, /* '{' */
+ YYSYMBOL_17_ = 17, /* '}' */
+ YYSYMBOL_18_ = 18, /* ';' */
+ YYSYMBOL_19_ = 19, /* '&' */
+ YYSYMBOL_20_ = 20, /* '=' */
+ YYSYMBOL_21_ = 21, /* '^' */
+ YYSYMBOL_YYACCEPT = 22, /* $accept */
+ YYSYMBOL_rc = 23, /* rc */
+ YYSYMBOL_line = 24, /* line */
+ YYSYMBOL_body = 25, /* body */
+ YYSYMBOL_paren = 26, /* paren */
+ YYSYMBOL_block = 27, /* block */
+ YYSYMBOL_cmds = 28, /* cmds */
+ YYSYMBOL_cmdsln = 29, /* cmdsln */
+ YYSYMBOL_ifbody = 30, /* ifbody */
+ YYSYMBOL_cmd = 31, /* cmd */
+ YYSYMBOL_basic = 32, /* basic */
+ YYSYMBOL_atom = 33, /* atom */
+ YYSYMBOL_word = 34, /* word */
+ YYSYMBOL_executable = 35, /* executable */
+ YYSYMBOL_nonkeyword = 36, /* nonkeyword */
+ YYSYMBOL_keyword = 37, /* keyword */
+ YYSYMBOL_nl = 38 /* nl */
+};
+typedef enum yysymbol_kind_t yysymbol_kind_t;
+
+
+
+
+#ifdef short
+# undef short
+#endif
+
+/* On compilers that do not define __PTRDIFF_MAX__ etc., make sure
+ <limits.h> and (if available) <stdint.h> are included
+ so that the code can choose integer types of a good width. */
+
+#ifndef __PTRDIFF_MAX__
+# include <limits.h> /* INFRINGES ON USER NAME SPACE */
+# if defined __STDC_VERSION__ && 199901 <= __STDC_VERSION__
+# include <stdint.h> /* INFRINGES ON USER NAME SPACE */
+# define YY_STDINT_H
+# endif
+#endif
+
+/* Narrow types that promote to a signed type and that can represent a
+ signed or unsigned integer of at least N bits. In tables they can
+ save space and decrease cache pressure. Promoting to a signed type
+ helps avoid bugs in integer arithmetic. */
+
+#ifdef __INT_LEAST8_MAX__
+typedef __INT_LEAST8_TYPE__ yytype_int8;
+#elif defined YY_STDINT_H
+typedef int_least8_t yytype_int8;
+#else
+typedef signed char yytype_int8;
+#endif
+
+#ifdef __INT_LEAST16_MAX__
+typedef __INT_LEAST16_TYPE__ yytype_int16;
+#elif defined YY_STDINT_H
+typedef int_least16_t yytype_int16;
+#else
+typedef short yytype_int16;
+#endif
+
+/* Work around bug in HP-UX 11.23, which defines these macros
+ incorrectly for preprocessor constants. This workaround can likely
+ be removed in 2023, as HPE has promised support for HP-UX 11.23
+ (aka HP-UX 11i v2) only through the end of 2022; see Table 2 of
+ <https://h20195.www2.hpe.com/V2/getpdf.aspx/4AA4-7673ENW.pdf>. */
+#ifdef __hpux
+# undef UINT_LEAST8_MAX
+# undef UINT_LEAST16_MAX
+# define UINT_LEAST8_MAX 255
+# define UINT_LEAST16_MAX 65535
+#endif
+
+#if defined __UINT_LEAST8_MAX__ && __UINT_LEAST8_MAX__ <= __INT_MAX__
+typedef __UINT_LEAST8_TYPE__ yytype_uint8;
+#elif (!defined __UINT_LEAST8_MAX__ && defined YY_STDINT_H \
+ && UINT_LEAST8_MAX <= INT_MAX)
+typedef uint_least8_t yytype_uint8;
+#elif !defined __UINT_LEAST8_MAX__ && UCHAR_MAX <= INT_MAX
+typedef unsigned char yytype_uint8;
+#else
+typedef short yytype_uint8;
+#endif
+
+#if defined __UINT_LEAST16_MAX__ && __UINT_LEAST16_MAX__ <= __INT_MAX__
+typedef __UINT_LEAST16_TYPE__ yytype_uint16;
+#elif (!defined __UINT_LEAST16_MAX__ && defined YY_STDINT_H \
+ && UINT_LEAST16_MAX <= INT_MAX)
+typedef uint_least16_t yytype_uint16;
+#elif !defined __UINT_LEAST16_MAX__ && USHRT_MAX <= INT_MAX
+typedef unsigned short yytype_uint16;
+#else
+typedef int yytype_uint16;
+#endif
+
+#ifndef YYPTRDIFF_T
+# if defined __PTRDIFF_TYPE__ && defined __PTRDIFF_MAX__
+# define YYPTRDIFF_T __PTRDIFF_TYPE__
+# define YYPTRDIFF_MAXIMUM __PTRDIFF_MAX__
+# elif defined PTRDIFF_MAX
+# ifndef ptrdiff_t
+# include <stddef.h> /* INFRINGES ON USER NAME SPACE */
+# endif
+# define YYPTRDIFF_T ptrdiff_t
+# define YYPTRDIFF_MAXIMUM PTRDIFF_MAX
+# else
+# define YYPTRDIFF_T long
+# define YYPTRDIFF_MAXIMUM LONG_MAX
+# endif
+#endif
+
+#ifndef YYSIZE_T
+# ifdef __SIZE_TYPE__
+# define YYSIZE_T __SIZE_TYPE__
+# elif defined size_t
+# define YYSIZE_T size_t
+# elif defined __STDC_VERSION__ && 199901 <= __STDC_VERSION__
+# include <stddef.h> /* INFRINGES ON USER NAME SPACE */
+# define YYSIZE_T size_t
+# else
+# define YYSIZE_T unsigned
+# endif
+#endif
+
+#define YYSIZE_MAXIMUM \
+ YY_CAST (YYPTRDIFF_T, \
+ (YYPTRDIFF_MAXIMUM < YY_CAST (YYSIZE_T, -1) \
+ ? YYPTRDIFF_MAXIMUM \
+ : YY_CAST (YYSIZE_T, -1)))
+
+#define YYSIZEOF(X) YY_CAST (YYPTRDIFF_T, sizeof (X))
+
+
+/* Stored state numbers (used for stacks). */
+typedef yytype_int8 yy_state_t;
+
+/* State numbers in computations. */
+typedef int yy_state_fast_t;
+
+#ifndef YY_
+# if defined YYENABLE_NLS && YYENABLE_NLS
+# if ENABLE_NLS
+# include <libintl.h> /* INFRINGES ON USER NAME SPACE */
+# define YY_(Msgid) dgettext ("bison-runtime", Msgid)
+# endif
+# endif
+# ifndef YY_
+# define YY_(Msgid) Msgid
+# endif
+#endif
+
+
+#ifndef YY_ATTRIBUTE_PURE
+# if defined __GNUC__ && 2 < __GNUC__ + (96 <= __GNUC_MINOR__)
+# define YY_ATTRIBUTE_PURE __attribute__ ((__pure__))
+# else
+# define YY_ATTRIBUTE_PURE
+# endif
+#endif
+
+#ifndef YY_ATTRIBUTE_UNUSED
+# if defined __GNUC__ && 2 < __GNUC__ + (7 <= __GNUC_MINOR__)
+# define YY_ATTRIBUTE_UNUSED __attribute__ ((__unused__))
+# else
+# define YY_ATTRIBUTE_UNUSED
+# endif
+#endif
+
+/* Suppress unused-variable warnings by "using" E. */
+#if ! defined lint || defined __GNUC__
+# define YY_USE(E) ((void) (E))
+#else
+# define YY_USE(E) /* empty */
+#endif
+
+/* Suppress an incorrect diagnostic about yylval being uninitialized. */
+#if defined __GNUC__ && ! defined __ICC && 406 <= __GNUC__ * 100 + __GNUC_MINOR__
+# if __GNUC__ * 100 + __GNUC_MINOR__ < 407
+# define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN \
+ _Pragma ("GCC diagnostic push") \
+ _Pragma ("GCC diagnostic ignored \"-Wuninitialized\"")
+# else
+# define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN \
+ _Pragma ("GCC diagnostic push") \
+ _Pragma ("GCC diagnostic ignored \"-Wuninitialized\"") \
+ _Pragma ("GCC diagnostic ignored \"-Wmaybe-uninitialized\"")
+# endif
+# define YY_IGNORE_MAYBE_UNINITIALIZED_END \
+ _Pragma ("GCC diagnostic pop")
+#else
+# define YY_INITIAL_VALUE(Value) Value
+#endif
+#ifndef YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+# define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+# define YY_IGNORE_MAYBE_UNINITIALIZED_END
+#endif
+#ifndef YY_INITIAL_VALUE
+# define YY_INITIAL_VALUE(Value) /* Nothing. */
+#endif
+
+#if defined __cplusplus && defined __GNUC__ && ! defined __ICC && 6 <= __GNUC__
+# define YY_IGNORE_USELESS_CAST_BEGIN \
+ _Pragma ("GCC diagnostic push") \
+ _Pragma ("GCC diagnostic ignored \"-Wuseless-cast\"")
+# define YY_IGNORE_USELESS_CAST_END \
+ _Pragma ("GCC diagnostic pop")
+#endif
+#ifndef YY_IGNORE_USELESS_CAST_BEGIN
+# define YY_IGNORE_USELESS_CAST_BEGIN
+# define YY_IGNORE_USELESS_CAST_END
+#endif
+
+
+#define YY_ASSERT(E) ((void) (0 && (E)))
+
+#if !defined yyoverflow
+
+/* The parser invokes alloca or malloc; define the necessary symbols. */
+
+# ifdef YYSTACK_USE_ALLOCA
+# if YYSTACK_USE_ALLOCA
+# ifdef __GNUC__
+# define YYSTACK_ALLOC __builtin_alloca
+# elif defined __BUILTIN_VA_ARG_INCR
+# include <alloca.h> /* INFRINGES ON USER NAME SPACE */
+# elif defined _AIX
+# define YYSTACK_ALLOC __alloca
+# elif defined _MSC_VER
+# include <malloc.h> /* INFRINGES ON USER NAME SPACE */
+# define alloca _alloca
+# else
+# define YYSTACK_ALLOC alloca
+# if ! defined _ALLOCA_H && ! defined EXIT_SUCCESS
+# include <stdlib.h> /* INFRINGES ON USER NAME SPACE */
+ /* Use EXIT_SUCCESS as a witness for stdlib.h. */
+# ifndef EXIT_SUCCESS
+# define EXIT_SUCCESS 0
+# endif
+# endif
+# endif
+# endif
+# endif
+
+# ifdef YYSTACK_ALLOC
+ /* Pacify GCC's 'empty if-body' warning. */
+# define YYSTACK_FREE(Ptr) do { /* empty */; } while (0)
+# ifndef YYSTACK_ALLOC_MAXIMUM
+ /* The OS might guarantee only one guard page at the bottom of the stack,
+ and a page size can be as small as 4096 bytes. So we cannot safely
+ invoke alloca (N) if N exceeds 4096. Use a slightly smaller number
+ to allow for a few compiler-allocated temporary stack slots. */
+# define YYSTACK_ALLOC_MAXIMUM 4032 /* reasonable circa 2006 */
+# endif
+# else
+# define YYSTACK_ALLOC YYMALLOC
+# define YYSTACK_FREE YYFREE
+# ifndef YYSTACK_ALLOC_MAXIMUM
+# define YYSTACK_ALLOC_MAXIMUM YYSIZE_MAXIMUM
+# endif
+# if (defined __cplusplus && ! defined EXIT_SUCCESS \
+ && ! ((defined YYMALLOC || defined malloc) \
+ && (defined YYFREE || defined free)))
+# include <stdlib.h> /* INFRINGES ON USER NAME SPACE */
+# ifndef EXIT_SUCCESS
+# define EXIT_SUCCESS 0
+# endif
+# endif
+# ifndef YYMALLOC
+# define YYMALLOC malloc
+# if ! defined malloc && ! defined EXIT_SUCCESS
+void *malloc (YYSIZE_T); /* INFRINGES ON USER NAME SPACE */
+# endif
+# endif
+# ifndef YYFREE
+# define YYFREE free
+# if ! defined free && ! defined EXIT_SUCCESS
+void free (void *); /* INFRINGES ON USER NAME SPACE */
+# endif
+# endif
+# endif
+#endif /* !defined yyoverflow */
+
+#if (! defined yyoverflow \
+ && (! defined __cplusplus \
+ || (defined YYSTYPE_IS_TRIVIAL && YYSTYPE_IS_TRIVIAL)))
+
+/* A type that is properly aligned for any stack member. */
+union yyalloc
+{
+ yy_state_t yyss_alloc;
+ YYSTYPE yyvs_alloc;
+};
+
+/* The size of the maximum gap between one aligned stack and the next. */
+# define YYSTACK_GAP_MAXIMUM (YYSIZEOF (union yyalloc) - 1)
+
+/* The size of an array large to enough to hold all stacks, each with
+ N elements. */
+# define YYSTACK_BYTES(N) \
+ ((N) * (YYSIZEOF (yy_state_t) + YYSIZEOF (YYSTYPE)) \
+ + YYSTACK_GAP_MAXIMUM)
+
+# define YYCOPY_NEEDED 1
+
+/* Relocate STACK from its old location to the new one. The
+ local variables YYSIZE and YYSTACKSIZE give the old and new number of
+ elements in the stack, and YYPTR gives the new location of the
+ stack. Advance YYPTR to a properly aligned location for the next
+ stack. */
+# define YYSTACK_RELOCATE(Stack_alloc, Stack) \
+ do \
+ { \
+ YYPTRDIFF_T yynewbytes; \
+ YYCOPY (&yyptr->Stack_alloc, Stack, yysize); \
+ Stack = &yyptr->Stack_alloc; \
+ yynewbytes = yystacksize * YYSIZEOF (*Stack) + YYSTACK_GAP_MAXIMUM; \
+ yyptr += yynewbytes / YYSIZEOF (*yyptr); \
+ } \
+ while (0)
+
+#endif
+
+#if defined YYCOPY_NEEDED && YYCOPY_NEEDED
+/* Copy COUNT objects from SRC to DST. The source and destination do
+ not overlap. */
+# ifndef YYCOPY
+# if defined __GNUC__ && 1 < __GNUC__
+# define YYCOPY(Dst, Src, Count) \
+ __builtin_memcpy (Dst, Src, YY_CAST (YYSIZE_T, (Count)) * sizeof (*(Src)))
+# else
+# define YYCOPY(Dst, Src, Count) \
+ do \
+ { \
+ YYPTRDIFF_T yyi; \
+ for (yyi = 0; yyi < (Count); yyi++) \
+ (Dst)[yyi] = (Src)[yyi]; \
+ } \
+ while (0)
+# endif
+# endif
+#endif /* !YYCOPY_NEEDED */
+
+/* YYFINAL -- State number of the termination state. */
+#define YYFINAL 24
+/* YYLAST -- Last index in YYTABLE. */
+#define YYLAST 49
+
+/* YYNTOKENS -- Number of terminals. */
+#define YYNTOKENS 22
+/* YYNNTS -- Number of nonterminals. */
+#define YYNNTS 17
+/* YYNRULES -- Number of rules. */
+#define YYNRULES 33
+/* YYNSTATES -- Number of states. */
+#define YYNSTATES 48
+
+/* YYMAXUTOK -- Last valid token kind. */
+#define YYMAXUTOK 266
+
+
+/* YYTRANSLATE(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM
+ as returned by yylex, with out-of-bounds checking. */
+#define YYTRANSLATE(YYX) \
+ (0 <= (YYX) && (YYX) <= YYMAXUTOK \
+ ? YY_CAST (yysymbol_kind_t, yytranslate[YYX]) \
+ : YYSYMBOL_YYUNDEF)
+
+/* YYTRANSLATE[TOKEN-NUM] -- Symbol number corresponding to TOKEN-NUM
+ as returned by yylex. */
+static const yytype_int8 yytranslate[] =
+{
+ 0, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 12, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 13, 2, 19, 2,
+ 14, 15, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 18,
+ 2, 20, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 21, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 16, 2, 17, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 1, 2, 3, 4,
+ 5, 6, 7, 8, 9, 10, 11
+};
+
+#if YYDEBUG
+/* YYRLINE[YYN] -- Source line where rule number YYN was defined. */
+static const yytype_int8 yyrline[] =
+{
+ 0, 34, 34, 35, 38, 39, 42, 43, 46, 49,
+ 52, 53, 56, 57, 60, 61, 67, 68, 69, 70,
+ 73, 74, 83, 84, 87, 88, 91, 92, 95, 96,
+ 99, 99, 101, 103
+};
+#endif
+
+/** Accessing symbol of state STATE. */
+#define YY_ACCESSING_SYMBOL(State) YY_CAST (yysymbol_kind_t, yystos[State])
+
+#if YYDEBUG || 0
+/* The user-facing name of the symbol whose (internal) number is
+ YYSYMBOL. No bounds checking. */
+static const char *yysymbol_name (yysymbol_kind_t yysymbol) YY_ATTRIBUTE_UNUSED;
+
+/* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
+ First, the terminals, then, starting at YYNTOKENS, nonterminals. */
+static const char *const yytname[] =
+{
+ "\"end of file\"", "error", "\"invalid token\"", "Tword", "Tif",
+ "Telse", "Tbang", "Targs", "Tbasic", "Tparen", "Tblock", "Twhile",
+ "'\\n'", "'$'", "'('", "')'", "'{'", "'}'", "';'", "'&'", "'='", "'^'",
+ "$accept", "rc", "line", "body", "paren", "block", "cmds", "cmdsln",
+ "ifbody", "cmd", "basic", "atom", "word", "executable", "nonkeyword",
+ "keyword", "nl", YY_NULLPTR
+};
+
+static const char *
+yysymbol_name (yysymbol_kind_t yysymbol)
+{
+ return yytname[yysymbol];
+}
+#endif
+
+#define YYPACT_NINF (-10)
+
+#define yypact_value_is_default(Yyn) \
+ ((Yyn) == YYPACT_NINF)
+
+#define YYTABLE_NINF (-3)
+
+#define yytable_value_is_error(Yyn) \
+ 0
+
+/* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
+ STATE-NUM. */
+static const yytype_int8 yypact[] =
+{
+ 3, -10, -2, 21, 7, 15, 9, -10, 7, 22,
+ 21, 10, -10, 7, -10, -10, -10, -10, -10, -10,
+ 18, -10, 7, 20, -10, -10, -10, -10, -10, -10,
+ 23, 21, 27, 1, -10, -10, -10, 21, -10, -10,
+ -10, 38, -10, -10, -10, -10, 1, -10
+};
+
+/* YYDEFACT[STATE-NUM] -- Default reduction number in state STATE-NUM.
+ Performed when YYTABLE does not specify something else to do. Zero
+ means the default is an error. */
+static const yytype_int8 yydefact[] =
+{
+ 16, 28, 0, 0, 16, 0, 0, 18, 16, 4,
+ 17, 20, 26, 16, 32, 30, 31, 29, 22, 23,
+ 0, 12, 16, 6, 1, 3, 5, 10, 11, 24,
+ 21, 0, 0, 16, 9, 7, 13, 0, 27, 8,
+ 33, 18, 19, 14, 25, 32, 16, 15
+};
+
+/* YYPGOTO[NTERM-NUM]. */
+static const yytype_int8 yypgoto[] =
+{
+ -10, -10, 37, 5, -10, 14, 29, -10, -10, 0,
+ -10, -9, -10, -10, -1, -10, 4
+};
+
+/* YYDEFGOTO[NTERM-NUM]. */
+static const yytype_int8 yydefgoto[] =
+{
+ 0, 5, 6, 20, 14, 7, 21, 22, 42, 23,
+ 10, 17, 30, 11, 12, 19, 33
+};
+
+/* YYTABLE[YYPACT[STATE-NUM]] -- What to do in state STATE-NUM. If
+ positive, shift that token. If negative, reduce the rule whose
+ number is the opposite. If YYTABLE_NINF, syntax error. */
+static const yytype_int8 yytable[] =
+{
+ 9, 29, 18, -2, 1, 2, 1, 2, 9, 18,
+ 1, 2, 13, 40, 3, 24, 3, 4, 32, 4,
+ 3, 25, 38, 4, 1, 15, 16, 35, 44, 8,
+ 18, 31, 36, 43, 3, 34, 18, 8, 27, 28,
+ 27, 28, 39, 45, 37, 26, 47, 41, 0, 46
+};
+
+static const yytype_int8 yycheck[] =
+{
+ 0, 10, 3, 0, 3, 4, 3, 4, 8, 10,
+ 3, 4, 14, 12, 13, 0, 13, 16, 13, 16,
+ 13, 12, 31, 16, 3, 4, 5, 22, 37, 0,
+ 31, 21, 12, 33, 13, 17, 37, 8, 18, 19,
+ 18, 19, 15, 5, 21, 8, 46, 33, -1, 45
+};
+
+/* YYSTOS[STATE-NUM] -- The symbol kind of the accessing symbol of
+ state STATE-NUM. */
+static const yytype_int8 yystos[] =
+{
+ 0, 3, 4, 13, 16, 23, 24, 27, 28, 31,
+ 32, 35, 36, 14, 26, 4, 5, 33, 36, 37,
+ 25, 28, 29, 31, 0, 12, 24, 18, 19, 33,
+ 34, 21, 25, 38, 17, 25, 12, 21, 33, 15,
+ 12, 27, 30, 31, 33, 5, 38, 31
+};
+
+/* YYR1[RULE-NUM] -- Symbol kind of the left-hand side of rule RULE-NUM. */
+static const yytype_int8 yyr1[] =
+{
+ 0, 22, 23, 23, 24, 24, 25, 25, 26, 27,
+ 28, 28, 29, 29, 30, 30, 31, 31, 31, 31,
+ 32, 32, 33, 33, 34, 34, 35, 35, 36, 36,
+ 37, 37, 38, 38
+};
+
+/* YYR2[RULE-NUM] -- Number of symbols on the right-hand side of rule RULE-NUM. */
+static const yytype_int8 yyr2[] =
+{
+ 0, 2, 0, 2, 1, 2, 1, 2, 3, 3,
+ 2, 2, 1, 2, 1, 4, 0, 1, 1, 4,
+ 1, 2, 1, 1, 1, 3, 1, 3, 1, 2,
+ 1, 1, 0, 2
+};
+
+
+enum { YYENOMEM = -2 };
+
+#define yyerrok (yyerrstatus = 0)
+#define yyclearin (yychar = YYEMPTY)
+
+#define YYACCEPT goto yyacceptlab
+#define YYABORT goto yyabortlab
+#define YYERROR goto yyerrorlab
+#define YYNOMEM goto yyexhaustedlab
+
+
+#define YYRECOVERING() (!!yyerrstatus)
+
+#define YYBACKUP(Token, Value) \
+ do \
+ if (yychar == YYEMPTY) \
+ { \
+ yychar = (Token); \
+ yylval = (Value); \
+ YYPOPSTACK (yylen); \
+ yystate = *yyssp; \
+ goto yybackup; \
+ } \
+ else \
+ { \
+ yyerror (YY_("syntax error: cannot back up")); \
+ YYERROR; \
+ } \
+ while (0)
+
+/* Backward compatibility with an undocumented macro.
+ Use YYerror or YYUNDEF. */
+#define YYERRCODE YYUNDEF
+
+
+/* Enable debugging if requested. */
+#if YYDEBUG
+
+# ifndef YYFPRINTF
+# include <stdio.h> /* INFRINGES ON USER NAME SPACE */
+# define YYFPRINTF fprintf
+# endif
+
+# define YYDPRINTF(Args) \
+do { \
+ if (yydebug) \
+ YYFPRINTF Args; \
+} while (0)
+
+
+
+
+# define YY_SYMBOL_PRINT(Title, Kind, Value, Location) \
+do { \
+ if (yydebug) \
+ { \
+ YYFPRINTF (stderr, "%s ", Title); \
+ yy_symbol_print (stderr, \
+ Kind, Value); \
+ YYFPRINTF (stderr, "\n"); \
+ } \
+} while (0)
+
+
+/*-----------------------------------.
+| Print this symbol's value on YYO. |
+`-----------------------------------*/
+
+static void
+yy_symbol_value_print (FILE *yyo,
+ yysymbol_kind_t yykind, YYSTYPE const * const yyvaluep)
+{
+ FILE *yyoutput = yyo;
+ YY_USE (yyoutput);
+ if (!yyvaluep)
+ return;
+ YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+ YY_USE (yykind);
+ YY_IGNORE_MAYBE_UNINITIALIZED_END
+}
+
+
+/*---------------------------.
+| Print this symbol on YYO. |
+`---------------------------*/
+
+static void
+yy_symbol_print (FILE *yyo,
+ yysymbol_kind_t yykind, YYSTYPE const * const yyvaluep)
+{
+ YYFPRINTF (yyo, "%s %s (",
+ yykind < YYNTOKENS ? "token" : "nterm", yysymbol_name (yykind));
+
+ yy_symbol_value_print (yyo, yykind, yyvaluep);
+ YYFPRINTF (yyo, ")");
+}
+
+/*------------------------------------------------------------------.
+| yy_stack_print -- Print the state stack from its BOTTOM up to its |
+| TOP (included). |
+`------------------------------------------------------------------*/
+
+static void
+yy_stack_print (yy_state_t *yybottom, yy_state_t *yytop)
+{
+ YYFPRINTF (stderr, "Stack now");
+ for (; yybottom <= yytop; yybottom++)
+ {
+ int yybot = *yybottom;
+ YYFPRINTF (stderr, " %d", yybot);
+ }
+ YYFPRINTF (stderr, "\n");
+}
+
+# define YY_STACK_PRINT(Bottom, Top) \
+do { \
+ if (yydebug) \
+ yy_stack_print ((Bottom), (Top)); \
+} while (0)
+
+
+/*------------------------------------------------.
+| Report that the YYRULE is going to be reduced. |
+`------------------------------------------------*/
+
+static void
+yy_reduce_print (yy_state_t *yyssp, YYSTYPE *yyvsp,
+ int yyrule)
+{
+ int yylno = yyrline[yyrule];
+ int yynrhs = yyr2[yyrule];
+ int yyi;
+ YYFPRINTF (stderr, "Reducing stack by rule %d (line %d):\n",
+ yyrule - 1, yylno);
+ /* The symbols being reduced. */
+ for (yyi = 0; yyi < yynrhs; yyi++)
+ {
+ YYFPRINTF (stderr, " $%d = ", yyi + 1);
+ yy_symbol_print (stderr,
+ YY_ACCESSING_SYMBOL (+yyssp[yyi + 1 - yynrhs]),
+ &yyvsp[(yyi + 1) - (yynrhs)]);
+ YYFPRINTF (stderr, "\n");
+ }
+}
+
+# define YY_REDUCE_PRINT(Rule) \
+do { \
+ if (yydebug) \
+ yy_reduce_print (yyssp, yyvsp, Rule); \
+} while (0)
+
+/* Nonzero means print parse trace. It is left uninitialized so that
+ multiple parsers can coexist. */
+int yydebug;
+#else /* !YYDEBUG */
+# define YYDPRINTF(Args) ((void) 0)
+# define YY_SYMBOL_PRINT(Title, Kind, Value, Location)
+# define YY_STACK_PRINT(Bottom, Top)
+# define YY_REDUCE_PRINT(Rule)
+#endif /* !YYDEBUG */
+
+
+/* YYINITDEPTH -- initial size of the parser's stacks. */
+#ifndef YYINITDEPTH
+# define YYINITDEPTH 200
+#endif
+
+/* YYMAXDEPTH -- maximum size the stacks can grow to (effective only
+ if the built-in stack extension method is used).
+
+ Do not make this value too large; the results are undefined if
+ YYSTACK_ALLOC_MAXIMUM < YYSTACK_BYTES (YYMAXDEPTH)
+ evaluated with infinite-precision integer arithmetic. */
+
+#ifndef YYMAXDEPTH
+# define YYMAXDEPTH 10000
+#endif
+
+
+
+
+
+
+/*-----------------------------------------------.
+| Release the memory associated to this symbol. |
+`-----------------------------------------------*/
+
+static void
+yydestruct (const char *yymsg,
+ yysymbol_kind_t yykind, YYSTYPE *yyvaluep)
+{
+ YY_USE (yyvaluep);
+ if (!yymsg)
+ yymsg = "Deleting";
+ YY_SYMBOL_PRINT (yymsg, yykind, yyvaluep, yylocationp);
+
+ YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+ YY_USE (yykind);
+ YY_IGNORE_MAYBE_UNINITIALIZED_END
+}
+
+
+/* Lookahead token kind. */
+int yychar;
+
+/* The semantic value of the lookahead symbol. */
+YYSTYPE yylval;
+/* Number of syntax errors so far. */
+int yynerrs;
+
+
+
+
+/*----------.
+| yyparse. |
+`----------*/
+
+int
+yyparse (void)
+{
+ yy_state_fast_t yystate = 0;
+ /* Number of tokens to shift before error messages enabled. */
+ int yyerrstatus = 0;
+
+ /* Refer to the stacks through separate pointers, to allow yyoverflow
+ to reallocate them elsewhere. */
+
+ /* Their size. */
+ YYPTRDIFF_T yystacksize = YYINITDEPTH;
+
+ /* The state stack: array, bottom, top. */
+ yy_state_t yyssa[YYINITDEPTH];
+ yy_state_t *yyss = yyssa;
+ yy_state_t *yyssp = yyss;
+
+ /* The semantic value stack: array, bottom, top. */
+ YYSTYPE yyvsa[YYINITDEPTH];
+ YYSTYPE *yyvs = yyvsa;
+ YYSTYPE *yyvsp = yyvs;
+
+ int yyn;
+ /* The return value of yyparse. */
+ int yyresult;
+ /* Lookahead symbol kind. */
+ yysymbol_kind_t yytoken = YYSYMBOL_YYEMPTY;
+ /* The variables used to return semantic value and location from the
+ action routines. */
+ YYSTYPE yyval;
+
+
+
+#define YYPOPSTACK(N) (yyvsp -= (N), yyssp -= (N))
+
+ /* The number of symbols on the RHS of the reduced rule.
+ Keep to zero when no symbol should be popped. */
+ int yylen = 0;
+
+ YYDPRINTF ((stderr, "Starting parse\n"));
+
+ yychar = YYEMPTY; /* Cause a token to be read. */
+
+ goto yysetstate;
+
+
+/*------------------------------------------------------------.
+| yynewstate -- push a new state, which is found in yystate. |
+`------------------------------------------------------------*/
+yynewstate:
+ /* In all cases, when you get here, the value and location stacks
+ have just been pushed. So pushing a state here evens the stacks. */
+ yyssp++;
+
+
+/*--------------------------------------------------------------------.
+| yysetstate -- set current state (the top of the stack) to yystate. |
+`--------------------------------------------------------------------*/
+yysetstate:
+ YYDPRINTF ((stderr, "Entering state %d\n", yystate));
+ YY_ASSERT (0 <= yystate && yystate < YYNSTATES);
+ YY_IGNORE_USELESS_CAST_BEGIN
+ *yyssp = YY_CAST (yy_state_t, yystate);
+ YY_IGNORE_USELESS_CAST_END
+ YY_STACK_PRINT (yyss, yyssp);
+
+ if (yyss + yystacksize - 1 <= yyssp)
+#if !defined yyoverflow && !defined YYSTACK_RELOCATE
+ YYNOMEM;
+#else
+ {
+ /* Get the current used size of the three stacks, in elements. */
+ YYPTRDIFF_T yysize = yyssp - yyss + 1;
+
+# if defined yyoverflow
+ {
+ /* Give user a chance to reallocate the stack. Use copies of
+ these so that the &'s don't force the real ones into
+ memory. */
+ yy_state_t *yyss1 = yyss;
+ YYSTYPE *yyvs1 = yyvs;
+
+ /* Each stack pointer address is followed by the size of the
+ data in use in that stack, in bytes. This used to be a
+ conditional around just the two extra args, but that might
+ be undefined if yyoverflow is a macro. */
+ yyoverflow (YY_("memory exhausted"),
+ &yyss1, yysize * YYSIZEOF (*yyssp),
+ &yyvs1, yysize * YYSIZEOF (*yyvsp),
+ &yystacksize);
+ yyss = yyss1;
+ yyvs = yyvs1;
+ }
+# else /* defined YYSTACK_RELOCATE */
+ /* Extend the stack our own way. */
+ if (YYMAXDEPTH <= yystacksize)
+ YYNOMEM;
+ yystacksize *= 2;
+ if (YYMAXDEPTH < yystacksize)
+ yystacksize = YYMAXDEPTH;
+
+ {
+ yy_state_t *yyss1 = yyss;
+ union yyalloc *yyptr =
+ YY_CAST (union yyalloc *,
+ YYSTACK_ALLOC (YY_CAST (YYSIZE_T, YYSTACK_BYTES (yystacksize))));
+ if (! yyptr)
+ YYNOMEM;
+ YYSTACK_RELOCATE (yyss_alloc, yyss);
+ YYSTACK_RELOCATE (yyvs_alloc, yyvs);
+# undef YYSTACK_RELOCATE
+ if (yyss1 != yyssa)
+ YYSTACK_FREE (yyss1);
+ }
+# endif
+
+ yyssp = yyss + yysize - 1;
+ yyvsp = yyvs + yysize - 1;
+
+ YY_IGNORE_USELESS_CAST_BEGIN
+ YYDPRINTF ((stderr, "Stack size increased to %ld\n",
+ YY_CAST (long, yystacksize)));
+ YY_IGNORE_USELESS_CAST_END
+
+ if (yyss + yystacksize - 1 <= yyssp)
+ YYABORT;
+ }
+#endif /* !defined yyoverflow && !defined YYSTACK_RELOCATE */
+
+
+ if (yystate == YYFINAL)
+ YYACCEPT;
+
+ goto yybackup;
+
+
+/*-----------.
+| yybackup. |
+`-----------*/
+yybackup:
+ /* Do appropriate processing given the current state. Read a
+ lookahead token if we need one and don't already have one. */
+
+ /* First try to decide what to do without reference to lookahead token. */
+ yyn = yypact[yystate];
+ if (yypact_value_is_default (yyn))
+ goto yydefault;
+
+ /* Not known => get a lookahead token if don't already have one. */
+
+ /* YYCHAR is either empty, or end-of-input, or a valid lookahead. */
+ if (yychar == YYEMPTY)
+ {
+ YYDPRINTF ((stderr, "Reading a token\n"));
+ yychar = yylex ();
+ }
+
+ if (yychar <= YYEOF)
+ {
+ yychar = YYEOF;
+ yytoken = YYSYMBOL_YYEOF;
+ YYDPRINTF ((stderr, "Now at end of input.\n"));
+ }
+ else if (yychar == YYerror)
+ {
+ /* The scanner already issued an error message, process directly
+ to error recovery. But do not keep the error token as
+ lookahead, it is too special and may lead us to an endless
+ loop in error recovery. */
+ yychar = YYUNDEF;
+ yytoken = YYSYMBOL_YYerror;
+ goto yyerrlab1;
+ }
+ else
+ {
+ yytoken = YYTRANSLATE (yychar);
+ YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
+ }
+
+ /* If the proper action on seeing token YYTOKEN is to reduce or to
+ detect an error, take that action. */
+ yyn += yytoken;
+ if (yyn < 0 || YYLAST < yyn || yycheck[yyn] != yytoken)
+ goto yydefault;
+ yyn = yytable[yyn];
+ if (yyn <= 0)
+ {
+ if (yytable_value_is_error (yyn))
+ goto yyerrlab;
+ yyn = -yyn;
+ goto yyreduce;
+ }
+
+ /* Count tokens shifted since error; after three, turn off error
+ status. */
+ if (yyerrstatus)
+ yyerrstatus--;
+
+ /* Shift the lookahead token. */
+ YY_SYMBOL_PRINT ("Shifting", yytoken, &yylval, &yylloc);
+ yystate = yyn;
+ YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+ *++yyvsp = yylval;
+ YY_IGNORE_MAYBE_UNINITIALIZED_END
+
+ /* Discard the shifted token. */
+ yychar = YYEMPTY;
+ goto yynewstate;
+
+
+/*-----------------------------------------------------------.
+| yydefault -- do the default action for the current state. |
+`-----------------------------------------------------------*/
+yydefault:
+ yyn = yydefact[yystate];
+ if (yyn == 0)
+ goto yyerrlab;
+ goto yyreduce;
+
+
+/*-----------------------------.
+| yyreduce -- do a reduction. |
+`-----------------------------*/
+yyreduce:
+ /* yyn is the number of a rule to reduce with. */
+ yylen = yyr2[yyn];
+
+ /* If YYLEN is nonzero, implement the default value of the action:
+ '$$ = $1'.
+
+ Otherwise, the following line sets YYVAL to garbage.
+ This behavior is undocumented and Bison
+ users should not rely upon it. Assigning to YYVAL
+ unconditionally makes the parser a bit smaller, and it avoids a
+ GCC warning that YYVAL may be used uninitialized. */
+ yyval = yyvsp[1-yylen];
+
+
+ YY_REDUCE_PRINT (yyn);
+ switch (yyn)
+ {
+ case 2: /* rc: %empty */
+#line 34 "sys/cmd/rc/syntax.y"
+ { return 0; }
+#line 1125 "sys/cmd/rc/parse.c"
+ break;
+
+ case 3: /* rc: line '\n' */
+#line 35 "sys/cmd/rc/syntax.y"
+ { return compile((yyvsp[-1].tree)); }
+#line 1131 "sys/cmd/rc/parse.c"
+ break;
+
+ case 5: /* line: cmds line */
+#line 39 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree2(';', (yyvsp[-1].tree), (yyvsp[0].tree)); }
+#line 1137 "sys/cmd/rc/parse.c"
+ break;
+
+ case 7: /* body: cmdsln body */
+#line 43 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree2(';', (yyvsp[-1].tree), (yyvsp[0].tree)); }
+#line 1143 "sys/cmd/rc/parse.c"
+ break;
+
+ case 8: /* paren: '(' body ')' */
+#line 46 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree1(Tparen, (yyvsp[-1].tree)); }
+#line 1149 "sys/cmd/rc/parse.c"
+ break;
+
+ case 9: /* block: '{' body '}' */
+#line 49 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree1(Tblock, (yyvsp[-1].tree)); }
+#line 1155 "sys/cmd/rc/parse.c"
+ break;
+
+ case 11: /* cmds: cmd '&' */
+#line 53 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree1('&', (yyvsp[-1].tree)); }
+#line 1161 "sys/cmd/rc/parse.c"
+ break;
+
+ case 14: /* ifbody: cmd */
+#line 60 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree2(Tif, nil, (yyvsp[0].tree)); }
+#line 1167 "sys/cmd/rc/parse.c"
+ break;
+
+ case 15: /* ifbody: block Telse nl cmd */
+#line 61 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree3(Tif, nil, (yyvsp[-3].tree), (yyvsp[-2].tree)); }
+#line 1173 "sys/cmd/rc/parse.c"
+ break;
+
+ case 16: /* cmd: %empty */
+#line 67 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = nil; }
+#line 1179 "sys/cmd/rc/parse.c"
+ break;
+
+ case 17: /* cmd: basic */
+#line 68 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree1(Tbasic, (yyvsp[0].tree)); }
+#line 1185 "sys/cmd/rc/parse.c"
+ break;
+
+ case 19: /* cmd: Tif paren nl ifbody */
+#line 70 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = hangchild1((yyvsp[-2].tree), (yyvsp[-3].tree), 0); }
+#line 1191 "sys/cmd/rc/parse.c"
+ break;
+
+ case 21: /* basic: basic word */
+#line 74 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree2(Targs, (yyvsp[-1].tree), (yyvsp[0].tree)); }
+#line 1197 "sys/cmd/rc/parse.c"
+ break;
+
+ case 23: /* atom: keyword */
+#line 84 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree1(Tword, (yyvsp[0].tree)); }
+#line 1203 "sys/cmd/rc/parse.c"
+ break;
+
+ case 25: /* word: word '^' atom */
+#line 88 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree2('^', (yyvsp[-2].tree), (yyvsp[0].tree)); }
+#line 1209 "sys/cmd/rc/parse.c"
+ break;
+
+ case 27: /* executable: executable '^' atom */
+#line 92 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree2('^', (yyvsp[-2].tree), (yyvsp[0].tree)); }
+#line 1215 "sys/cmd/rc/parse.c"
+ break;
+
+ case 29: /* nonkeyword: '$' atom */
+#line 96 "sys/cmd/rc/syntax.y"
+ { (yyval.tree) = maketree1('$', (yyvsp[0].tree)); }
+#line 1221 "sys/cmd/rc/parse.c"
+ break;
+
+
+#line 1225 "sys/cmd/rc/parse.c"
+
+ default: break;
+ }
+ /* User semantic actions sometimes alter yychar, and that requires
+ that yytoken be updated with the new translation. We take the
+ approach of translating immediately before every use of yytoken.
+ One alternative is translating here after every semantic action,
+ but that translation would be missed if the semantic action invokes
+ YYABORT, YYACCEPT, or YYERROR immediately after altering yychar or
+ if it invokes YYBACKUP. In the case of YYABORT or YYACCEPT, an
+ incorrect destructor might then be invoked immediately. In the
+ case of YYERROR or YYBACKUP, subsequent parser actions might lead
+ to an incorrect destructor call or verbose syntax error message
+ before the lookahead is translated. */
+ YY_SYMBOL_PRINT ("-> $$ =", YY_CAST (yysymbol_kind_t, yyr1[yyn]), &yyval, &yyloc);
+
+ YYPOPSTACK (yylen);
+ yylen = 0;
+
+ *++yyvsp = yyval;
+
+ /* Now 'shift' the result of the reduction. Determine what state
+ that goes to, based on the state we popped back to and the rule
+ number reduced by. */
+ {
+ const int yylhs = yyr1[yyn] - YYNTOKENS;
+ const int yyi = yypgoto[yylhs] + *yyssp;
+ yystate = (0 <= yyi && yyi <= YYLAST && yycheck[yyi] == *yyssp
+ ? yytable[yyi]
+ : yydefgoto[yylhs]);
+ }
+
+ goto yynewstate;
+
+
+/*--------------------------------------.
+| yyerrlab -- here on detecting error. |
+`--------------------------------------*/
+yyerrlab:
+ /* Make sure we have latest lookahead translation. See comments at
+ user semantic actions for why this is necessary. */
+ yytoken = yychar == YYEMPTY ? YYSYMBOL_YYEMPTY : YYTRANSLATE (yychar);
+ /* If not already recovering from an error, report this error. */
+ if (!yyerrstatus)
+ {
+ ++yynerrs;
+ yyerror (YY_("syntax error"));
+ }
+
+ if (yyerrstatus == 3)
+ {
+ /* If just tried and failed to reuse lookahead token after an
+ error, discard it. */
+
+ if (yychar <= YYEOF)
+ {
+ /* Return failure if at end of input. */
+ if (yychar == YYEOF)
+ YYABORT;
+ }
+ else
+ {
+ yydestruct ("Error: discarding",
+ yytoken, &yylval);
+ yychar = YYEMPTY;
+ }
+ }
+
+ /* Else will try to reuse lookahead token after shifting the error
+ token. */
+ goto yyerrlab1;
+
+
+/*---------------------------------------------------.
+| yyerrorlab -- error raised explicitly by YYERROR. |
+`---------------------------------------------------*/
+yyerrorlab:
+ /* Pacify compilers when the user code never invokes YYERROR and the
+ label yyerrorlab therefore never appears in user code. */
+ if (0)
+ YYERROR;
+ ++yynerrs;
+
+ /* Do not reclaim the symbols of the rule whose action triggered
+ this YYERROR. */
+ YYPOPSTACK (yylen);
+ yylen = 0;
+ YY_STACK_PRINT (yyss, yyssp);
+ yystate = *yyssp;
+ goto yyerrlab1;
+
+
+/*-------------------------------------------------------------.
+| yyerrlab1 -- common code for both syntax error and YYERROR. |
+`-------------------------------------------------------------*/
+yyerrlab1:
+ yyerrstatus = 3; /* Each real token shifted decrements this. */
+
+ /* Pop stack until we find a state that shifts the error token. */
+ for (;;)
+ {
+ yyn = yypact[yystate];
+ if (!yypact_value_is_default (yyn))
+ {
+ yyn += YYSYMBOL_YYerror;
+ if (0 <= yyn && yyn <= YYLAST && yycheck[yyn] == YYSYMBOL_YYerror)
+ {
+ yyn = yytable[yyn];
+ if (0 < yyn)
+ break;
+ }
+ }
+
+ /* Pop the current state because it cannot handle the error token. */
+ if (yyssp == yyss)
+ YYABORT;
+
+
+ yydestruct ("Error: popping",
+ YY_ACCESSING_SYMBOL (yystate), yyvsp);
+ YYPOPSTACK (1);
+ yystate = *yyssp;
+ YY_STACK_PRINT (yyss, yyssp);
+ }
+
+ YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
+ *++yyvsp = yylval;
+ YY_IGNORE_MAYBE_UNINITIALIZED_END
+
+
+ /* Shift the error token. */
+ YY_SYMBOL_PRINT ("Shifting", YY_ACCESSING_SYMBOL (yyn), yyvsp, yylsp);
+
+ yystate = yyn;
+ goto yynewstate;
+
+
+/*-------------------------------------.
+| yyacceptlab -- YYACCEPT comes here. |
+`-------------------------------------*/
+yyacceptlab:
+ yyresult = 0;
+ goto yyreturnlab;
+
+
+/*-----------------------------------.
+| yyabortlab -- YYABORT comes here. |
+`-----------------------------------*/
+yyabortlab:
+ yyresult = 1;
+ goto yyreturnlab;
+
+
+/*-----------------------------------------------------------.
+| yyexhaustedlab -- YYNOMEM (memory exhaustion) comes here. |
+`-----------------------------------------------------------*/
+yyexhaustedlab:
+ yyerror (YY_("memory exhausted"));
+ yyresult = 2;
+ goto yyreturnlab;
+
+
+/*----------------------------------------------------------.
+| yyreturnlab -- parsing is finished, clean up and return. |
+`----------------------------------------------------------*/
+yyreturnlab:
+ if (yychar != YYEMPTY)
+ {
+ /* Make sure we have latest lookahead translation. See comments at
+ user semantic actions for why this is necessary. */
+ yytoken = YYTRANSLATE (yychar);
+ yydestruct ("Cleanup: discarding lookahead",
+ yytoken, &yylval);
+ }
+ /* Do not reclaim the symbols of the rule whose action triggered
+ this YYABORT or YYACCEPT. */
+ YYPOPSTACK (yylen);
+ YY_STACK_PRINT (yyss, yyssp);
+ while (yyssp != yyss)
+ {
+ yydestruct ("Cleanup: popping",
+ YY_ACCESSING_SYMBOL (+*yyssp), yyvsp);
+ YYPOPSTACK (1);
+ }
+#ifndef yyoverflow
+ if (yyss != yyssa)
+ YYSTACK_FREE (yyss);
+#endif
+
+ return yyresult;
+}
+
+#line 104 "sys/cmd/rc/syntax.y"
+
diff --git a/sys/cmd/rc/parse.h b/sys/cmd/rc/parse.h
new file mode 100644
index 0000000..5328340
--- /dev/null
+++ b/sys/cmd/rc/parse.h
@@ -0,0 +1,107 @@
+/* A Bison parser, made by GNU Bison 3.8.2. */
+
+/* Bison interface for Yacc-like parsers in C
+
+ Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2021 Free Software Foundation,
+ Inc.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* As a special exception, you may create a larger work that contains
+ part or all of the Bison parser skeleton and distribute that work
+ under terms of your choice, so long as that work isn't itself a
+ parser generator using the skeleton or a modified version thereof
+ as a parser skeleton. Alternatively, if you modify or redistribute
+ the parser skeleton itself, you may (at your option) remove this
+ special exception, which will cause the skeleton and the resulting
+ Bison output files to be licensed under the GNU General Public
+ License without this special exception.
+
+ This special exception was added by the Free Software Foundation in
+ version 2.2 of Bison. */
+
+/* DO NOT RELY ON FEATURES THAT ARE NOT DOCUMENTED in the manual,
+ especially those whose name start with YY_ or yy_. They are
+ private implementation details that can be changed or removed. */
+
+#ifndef YY_YY_SYS_CMD_RC_PARSE_H_INCLUDED
+# define YY_YY_SYS_CMD_RC_PARSE_H_INCLUDED
+/* Debug traces. */
+#ifndef YYDEBUG
+# define YYDEBUG 0
+#endif
+#if YYDEBUG
+extern int yydebug;
+#endif
+
+/* Token kinds. */
+#ifndef YYTOKENTYPE
+# define YYTOKENTYPE
+ enum yytokentype
+ {
+ YYEMPTY = -2,
+ YYEOF = 0, /* "end of file" */
+ YYerror = 256, /* error */
+ YYUNDEF = 257, /* "invalid token" */
+ Tword = 258, /* Tword */
+ Tif = 259, /* Tif */
+ Telse = 260, /* Telse */
+ Tbang = 261, /* Tbang */
+ Targs = 262, /* Targs */
+ Tbasic = 263, /* Tbasic */
+ Tparen = 264, /* Tparen */
+ Tblock = 265, /* Tblock */
+ Twhile = 266 /* Twhile */
+ };
+ typedef enum yytokentype yytoken_kind_t;
+#endif
+/* Token kinds. */
+#define YYEMPTY -2
+#define YYEOF 0
+#define YYerror 256
+#define YYUNDEF 257
+#define Tword 258
+#define Tif 259
+#define Telse 260
+#define Tbang 261
+#define Targs 262
+#define Tbasic 263
+#define Tparen 264
+#define Tblock 265
+#define Twhile 266
+
+/* Value type. */
+#if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
+union YYSTYPE
+{
+#line 20 "sys/cmd/rc/syntax.y"
+
+ struct Tree *tree;
+
+#line 93 "sys/cmd/rc/parse.h"
+
+};
+typedef union YYSTYPE YYSTYPE;
+# define YYSTYPE_IS_TRIVIAL 1
+# define YYSTYPE_IS_DECLARED 1
+#endif
+
+
+extern YYSTYPE yylval;
+
+
+int yyparse (void);
+
+
+#endif /* !YY_YY_SYS_CMD_RC_PARSE_H_INCLUDED */
diff --git a/sys/cmd/rc/prompt.c b/sys/cmd/rc/prompt.c
new file mode 100644
index 0000000..b4b1d96
--- /dev/null
+++ b/sys/cmd/rc/prompt.c
@@ -0,0 +1,17 @@
+#include "rc.h"
+
+int
+prompt(ushort *flag)
+{
+ int f = *flag;
+ if(f){
+ if(!readline("> ")){
+ shell->flag.eof = 1;
+ return 0;
+ }
+
+ shell->line++;
+ *flag = 0;
+ }
+ return 1;
+}
diff --git a/sys/cmd/rc/rc.h b/sys/cmd/rc/rc.h
new file mode 100644
index 0000000..1c2aa6b
--- /dev/null
+++ b/sys/cmd/rc/rc.h
@@ -0,0 +1,196 @@
+#pragma once
+
+#include <u.h>
+#include <libn.h>
+
+// -----------------------------------------------------------------------
+// types
+
+typedef struct Io Io;
+typedef struct Var Var;
+typedef struct Word Word;
+typedef struct List List;
+typedef struct Tree Tree;
+typedef struct Redir Redir;
+typedef union Code Code;
+typedef struct Thread Thread;
+
+typedef struct WaitMsg WaitMsg;
+
+struct Io
+{
+ int fd, cap;
+ char *s;
+ char *b, *e, buf[];
+};
+
+struct Tree
+{
+ int type;
+ char *str;
+ Tree *child[3];
+ Tree *link;
+};
+
+struct Word
+{
+ char *str;
+ Word *link;
+};
+
+struct List
+{
+ Word *word;
+ List *link;
+};
+
+/*
+ * the first word of any code vector is a reference count
+ * always create a new reference to a code vector by calling copycode()
+ * always call freecode() when deleting a reference
+ */
+union Code
+{
+ int i;
+ void (*f)(void);
+ char *s;
+};
+
+struct Var
+{
+ char *name;
+ Word *val;
+ short new : 1;
+ short newfunc : 1;
+ Code *func;
+ void (*update)(Var *);
+ Var *link;
+};
+
+enum
+{
+ Rclose,
+ Rdup,
+ Ropen,
+};
+
+struct Redir
+{
+ char type; /* what to do */
+ short from, to; /* what to do it to */
+ struct Redir *link; /* what else to do (reverse order) */
+};
+
+struct Thread
+{
+ struct {
+ int i;
+ Code *exe;
+ } code; // execution stack
+ struct {
+ Io *io;
+ char *path;
+ } cmd; // command input
+
+ List *args; // argument stack
+ Var *local; // local variables
+ Redir *redir; // list of redirections
+
+ struct {
+ ushort i : 1;
+ ushort eof : 1;
+ } flag; // flags for process
+
+ int pid;
+ long line;
+
+ Tree *nodes; // memory allocation
+ Thread *link; // process we return to
+};
+
+struct WaitMsg
+{
+ int pid; // of loved one
+ ulong time[3]; // of loved one & descendants
+ char *msg;
+};
+
+// -----------------------------------------------------------------------
+// globals
+
+extern int rcpid;
+extern Thread *shell;
+extern Io *errio;
+extern Code *compiled;
+
+// -----------------------------------------------------------------------
+// functions
+
+/* util.c */
+void itoa(char*, long i);
+void fatal(char *, ...);
+void *emalloc(uintptr);
+void *erealloc(void*, uintptr);
+void efree(void*);
+
+/* read.c */
+int readline(char *);
+void enablevi(void);
+
+/* prompt.c */
+int prompt(ushort *);
+
+/* io.c */
+Io *openfd(int fd);
+Io *openstr(void);
+void terminate(Io *io);
+
+int get(Io *);
+int put(Io **, char);
+
+void flush(Io *io);
+void print(Io *, char *, ...);
+
+/* lex.c */
+int iswordchar(int c);
+int yylex(void);
+
+/* tree.c */
+Tree *maketree(void);
+Tree *maketree1(int, Tree*);
+Tree *maketree2(int, Tree*, Tree*);
+Tree *maketree3(int, Tree*, Tree*, Tree*);
+
+Tree *token(int, char *);
+Tree *hangchild1(Tree *, Tree *, int at);
+
+void freeparsetree(void);
+
+/* sys.c */
+void initenv(void);
+
+void addwait(int);
+void clearwait(void);
+int waitfor(int);
+
+void execute(Word *, Word*);
+
+/* exec.c */
+// XXX: odd place for this
+int count(Word *);
+Word *makeword(char *str, Word *link);
+void freeword(Word *w);
+void initpath(void);
+
+/* var.c */
+Var *var(char*);
+Var *definevar(char*, Var *);
+Var *globalvar(char*);
+Var *makevar(char *name, Var *link);
+void setvar(char *, Word *);
+char **mkenv(void);
+
+/* code.c */
+int compile(Tree *);
+Code *copycode(Code *c);
+void freecode(Code *c);
diff --git a/sys/cmd/rc/rules.mk b/sys/cmd/rc/rules.mk
new file mode 100644
index 0000000..44c9b7a
--- /dev/null
+++ b/sys/cmd/rc/rules.mk
@@ -0,0 +1,29 @@
+include share/push.mk
+# Iterate through subdirectory tree
+
+# Local sources
+SRCS_$(d) :=\
+ $(d)/util.c\
+ $(d)/input.c\
+ $(d)/prompt.c\
+ $(d)/io.c\
+ $(d)/lex.c\
+ $(d)/parse.c\
+ $(d)/tree.c\
+ $(d)/code.c\
+ $(d)/var.c\
+ $(d)/sys.c\
+ $(d)/exec.c\
+ $(d)/main.c
+
+BINS_$(d) := $(d)/rc
+
+include share/paths.mk
+$(d)/parse.h $(d)/parse.c: $(d)/syntax.y
+ yacc --header=$(<D)/parse.h --output=$(<D)/parse.c $(<)
+
+# Local rules
+$(BINS_$(d)): $(OBJS_$(d)) $(OBJ_DIR)/sys/libn/libn.a $(d)/parse.h
+ $(COMPLINK)
+
+include share/pop.mk
diff --git a/sys/cmd/rc/syntax.y b/sys/cmd/rc/syntax.y
new file mode 100644
index 0000000..247cc8a
--- /dev/null
+++ b/sys/cmd/rc/syntax.y
@@ -0,0 +1,104 @@
+%token Tword Tif Telse Tbang
+%token Targs
+%token Tbasic Tparen Tblock
+
+%{
+ #include "rc.h"
+
+ int yylex(void);
+ void yyerror(char *);
+%}
+
+/* operator precendence: lowest first */
+%right Telse
+%left Twhile
+%left '\n'
+%left Tbang
+%right '$'
+
+/* semantic types */
+%union{
+ struct Tree *tree;
+}
+%type<tree> line cmds cmdsln body paren block ifbody assign;
+%type<tree> cmd basic executable nonkeyword keyword word atom arg args;
+%type<tree> Tbang;
+%type<tree> Tword Tif Telse;
+
+/* grammar */
+
+%start rc
+
+%%
+rc:
+/*empty*/ { return 0; }
+| line '\n' { return compile($1); }
+
+line:
+ cmd
+| cmds line { $$ = maketree2(';', $1, $2); }
+
+body:
+ cmd
+| cmdsln body { $$ = maketree2(';', $1, $2); }
+
+paren:
+ '(' body ')' { $$ = maketree1(Tparen, $2); }
+
+block:
+ '{' body '}' { $$ = maketree1(Tblock, $2); }
+
+cmds:
+ cmd ';'
+| cmd '&' { $$ = maketree1('&', $1); }
+
+cmdsln:
+ cmds
+| cmd '\n'
+
+ifbody:
+ cmd %prec Telse { $$ = maketree2(Tif, nil, $1); }
+| block Telse nl cmd { $$ = maketree3(Tif, nil, $1, $2); }
+
+assign:
+ executable '=' word { $$ = maketree2('=', $1, $3); }
+
+cmd:
+/* empty */ %prec Twhile { $$ = nil; }
+| basic { $$ = maketree1(Tbasic, $1); }
+| block
+| Tif paren nl ifbody { $$ = hangchild1($2, $1, 0); }
+
+basic:
+ executable
+| basic word { $$ = maketree2(Targs, $1, $2); }
+
+arg: word
+
+args:
+ arg
+| args arg { $$ = maketree2(Targs, $1, $2); }
+
+atom:
+ nonkeyword
+| keyword { $$ = maketree1(Tword, $1); }
+
+word:
+ atom
+| word '^' atom { $$ = maketree2('^', $1, $3); }
+
+executable:
+ nonkeyword
+| executable '^' atom { $$ = maketree2('^', $1, $3); }
+
+nonkeyword:
+ Tword
+| '$' atom { $$ = maketree1('$', $2); }
+
+keyword:
+ Tif|Telse
+
+nl:
+/*empty*/
+| nl '\n'
+%%
diff --git a/sys/cmd/rc/sys.c b/sys/cmd/rc/sys.c
new file mode 100644
index 0000000..2c6a19d
--- /dev/null
+++ b/sys/cmd/rc/sys.c
@@ -0,0 +1,139 @@
+#include "rc.h"
+
+struct Wait
+{
+ int len, cap, *pid;
+};
+
+static struct Wait wait;
+
+// -----------------------------------------------------------------------
+// internal
+
+static
+char**
+mkargv(Word *args)
+{
+ char **argv=emalloc((count(args)+2)*sizeof(char *));
+ char **argp=argv+1; /* leave one at front for runcoms */
+
+ for(;args;args=args->link)
+ *argp++=args->str;
+ *argp=nil;
+
+ return argv;
+}
+
+static
+Word*
+envval(char *s)
+{
+ Word *v;
+ char *t, c;
+
+ for(t=s; *t && *t!='\1'; t++)
+ ;
+
+ c = *t;
+ *t = '\0';
+
+ v = makeword(s, (c=='\0') ? nil : envval(t+1));
+ *t=c;
+
+ return v;
+}
+
+// -----------------------------------------------------------------------
+// exported
+
+void
+initenv(void)
+{
+ extern char **environ;
+
+ char *s;
+ char **env;
+
+ for(env=environ; *env; env++) {
+ for(s=*env; *s && *s != '(' && *s != '='; s++)
+ ;
+ switch(*s){
+ case '\0':
+ break;
+ case '(': /* ignore functions */
+ break;
+ case '=':
+ *s = '\0';
+ setvar(*env, envval(s+1));
+ *s = '=';
+ break;
+ }
+ }
+}
+
+void
+clearwait(void)
+{
+ wait.len = 0;
+}
+
+int
+havewait(int pid)
+{
+ int i;
+
+ for(i=0; i<wait.len; i++)
+ if(wait.pid[i] == pid)
+ return 1;
+ return 0;
+}
+
+void
+addwait(int pid)
+{
+ if(wait.len == wait.cap){
+ wait.cap = wait.cap + 2;
+ wait.pid = erealloc(wait.pid, wait.cap*sizeof(*wait.pid));
+ }
+ wait.pid[wait.len++] = pid;
+}
+
+/*
+int
+waitfor(int pid)
+{
+ Thread *p;
+ struct WaitMsg *w;
+ char errbuf[ERRMAX];
+
+ if(pid >= 0 && !havewait(pid))
+ return 0;
+}
+*/
+
+void
+execute(Word *cmd, Word *path)
+{
+ int nc;
+ char **argv = mkargv(cmd);
+ char **env = mkenv();
+ char file[1024];
+
+ for(; path; path=path->link){
+ nc = strlen(path->str);
+ if(nc < arrlen(file)){
+ strcpy(file, path->str);
+ if(*file){
+ strcat(file, "/");
+ nc++;
+ }
+ if(nc+strlen(argv[1]) < 1024){
+ strcat(file, argv[1]);
+ execve(file, argv+1, env);
+ }else
+ fatal("command name too long");
+ }
+ }
+ efree(argv);
+ fatal("failed to exec\n");
+}
diff --git a/sys/cmd/rc/tree.c b/sys/cmd/rc/tree.c
new file mode 100644
index 0000000..0e2146f
--- /dev/null
+++ b/sys/cmd/rc/tree.c
@@ -0,0 +1,79 @@
+#include "rc.h"
+#include "parse.h"
+
+static Tree *nodes;
+
+Tree*
+maketree(void)
+{
+ Tree *node = emalloc(sizeof(*node));
+
+ node->link = nodes;
+ nodes = node;
+ return node;
+}
+
+void
+freeparsetree(void)
+{
+ Tree *t, *nt;
+ for(t = nodes; t; t = nt) {
+ nt = t->link;
+ if(t->str)
+ efree(t->str);
+ efree(t);
+ }
+ nodes = nil;
+}
+
+Tree*
+maketree1(int type, Tree *c0)
+{
+ return maketree2(type, c0, nil);
+}
+
+Tree*
+maketree2(int type, Tree *c0, Tree *c1)
+{
+ return maketree3(type, c0, c1, nil);
+}
+
+Tree*
+maketree3(int type, Tree *c0, Tree *c1, Tree *c2)
+{
+ Tree *node = maketree();
+
+ node->type = type;
+ node->child[0] = c0;
+ node->child[1] = c1;
+ node->child[2] = c2;
+
+ return node;
+}
+
+Tree*
+hangchild1(Tree *node, Tree *c, int i)
+{
+ node->child[i] = c;
+
+ return node;
+}
+
+Tree*
+token(int type, char *s)
+{
+ Tree *node = maketree();
+
+ node->type = type;
+ node->str = strdup(s);
+
+ return node;
+}
+
+/*
+Tree*
+basic(Tree *node)
+{
+ return maketree1(Tbasic, node);
+}
+*/
diff --git a/sys/cmd/rc/util.c b/sys/cmd/rc/util.c
new file mode 100644
index 0000000..b0be788
--- /dev/null
+++ b/sys/cmd/rc/util.c
@@ -0,0 +1,65 @@
+#include "rc.h"
+
+void
+fatal(char *msg, ...)
+{
+ va_list args;
+ vfprintf(stderr, msg, args);
+ va_end(args);
+
+ abort();
+}
+
+void*
+emalloc(uintptr n)
+{
+ void *p;
+ if(!(p = malloc(n)))
+ fatal("out of memory: can't allocate %d bytes", n);
+
+ memset(p, 0, n);
+ return p;
+}
+
+void*
+erealloc(void *p, uintptr n)
+{
+ void *r;
+ if(!(r = realloc(p,n)))
+ fatal("out of memory: can't reallocate %d bytes", n);
+
+ return r;
+}
+
+void
+efree(void *p)
+{
+ if(p)
+ free(p);
+ // TODO: log the double free
+}
+
+
+char *bp;
+
+static
+void
+iacvt(int n)
+{
+ if(n<0){
+ *bp++='-';
+ n=-n; /* doesn't work for n==-inf */
+ }
+ if(n/10)
+ iacvt(n/10);
+
+ *bp++=n%10+'0';
+}
+
+void
+itoa(char *s, long n)
+{
+ bp = s;
+ iacvt(n);
+ *bp='\0';
+}
diff --git a/sys/cmd/rc/var.c b/sys/cmd/rc/var.c
new file mode 100644
index 0000000..f0e5f5b
--- /dev/null
+++ b/sys/cmd/rc/var.c
@@ -0,0 +1,271 @@
+#include "rc.h"
+
+static Var *globals[512];
+
+// -----------------------------------------------------------------------
+// internals
+
+static
+int
+hash(char *s, int len)
+{
+ int h =0, i = 1;
+ while(*s)
+ h += *s++*i++;
+
+ h %= len;
+ return h < 0 ? h+len : h;
+}
+
+static
+void
+·setvar(char *name, Word *val, int call)
+{
+ Var *v = var(name);
+ freeword(v->val);
+
+ v->val = val;
+ v->new = 1; // this never turns off?
+
+ if(call && v->update)
+ v->update(v);
+}
+
+static
+char*
+list2strcolon(Word *words)
+{
+ char *value, *s, *t;
+ int len = 0;
+ Word *ap;
+ for(ap = words;ap;ap = ap->link)
+ len+=1+strlen(ap->str);
+
+ value = emalloc(len+1);
+
+ s = value;
+ for(ap = words; ap; ap = ap->link){
+ for(t = ap->str;*t;) *s++=*t++;
+ *s++=':';
+ }
+
+ if(s==value)
+ *s='\0';
+ else
+ s[-1]='\0';
+
+ return value;
+}
+
+static
+void
+littlepath(Var *v)
+{
+ /* convert $path to $PATH */
+ char *p;
+ Word *w;
+
+ p = list2strcolon(v->val);
+ w = emalloc(sizeof(*w));
+ w->str = p;
+ w->link = nil;
+
+ ·setvar("PATH", w, 1);
+}
+
+static
+void
+bigpath(Var *v)
+{
+ /* convert $PATH to $path */
+ char *p, *q;
+ Word **l, *w;
+
+ if(v->val == nil){
+ ·setvar("path", nil, 0);
+ return;
+ }
+
+ p = v->val->str;
+ w = nil;
+ l = &w;
+
+ /* Doesn't handle escaped colon nonsense. */
+ if(p[0] == 0)
+ p = nil;
+
+ while(p){
+ q = strchr(p, ':');
+ if(q)
+ *q = 0;
+
+ *l = makeword(p[0] ? p : ".", nil);
+ l = &(*l)->link;
+
+ if(q){
+ *q = ':';
+ p = q+1;
+ }else
+ p = nil;
+ }
+ ·setvar("path", w, 0);
+}
+
+
+
+// -----------------------------------------------------------------------
+// exports
+
+Var*
+makevar(char *name, Var *link)
+{
+ Var *v = emalloc(sizeof(*v));
+
+ v->name = name;
+ v->val = 0;
+ v->new = 0;
+ v->newfunc = 0;
+ v->link = link;
+ v->func = nil;
+ v->update = nil;
+
+ return v;
+}
+
+void
+setvar(char *name, Word *val)
+{
+ ·setvar(name, val, 1);
+}
+
+Var*
+definevar(char *name, Var *link)
+{
+ Var *v = emalloc(sizeof(*v));
+
+ v->name = name;
+ v->val = 0;
+ v->link = link;
+
+ return v;
+}
+
+Var*
+globalvar(char *name)
+{
+ int h;
+ Var *v;
+
+ h = hash(name, arrlen(globals));
+
+ if(strcmp(name,"PATH")==0){
+ flush(errio);
+ }
+
+ for(v = globals[h]; v; v = v->link){
+ if(strcmp(v->name, name) == 0){
+ return v;
+ }
+ }
+
+ return globals[h] = definevar(strdup(name), globals[h]);
+}
+
+Var*
+var(char *name)
+{
+ Var *v;
+ if(shell){
+ for(v = shell->local; v; v=v->link)
+ if(strcmp(v->name, name) == 0)
+ return v;
+ }
+ return globalvar(name);
+}
+
+static
+int
+cmpenv(const void *a, const void *b)
+{
+ return strcmp(*(char**)a, *(char**)b);
+}
+
+char**
+mkenv(void)
+{
+ char **env, **ep, *p, *q;
+ Var **h, *v;
+ Word *a;
+ int nvar=0, nchr=0, sep;
+
+#define BODY \
+ if((v==var(v->name)) && v->val){ \
+ nvar++; \
+ nchr+=strlen(v->name)+1; \
+ for(a=v->val;a;a=a->link) \
+ nchr+=strlen(a->str)+1; \
+ }
+
+ for(v= shell->local; v; v=v->link){
+ BODY
+ }
+ for(h=globals; h!=arrend(globals); h++){
+ for(v = *h; v; v=v->link){
+ BODY
+ }
+ }
+
+#undef BODY
+
+ env=emalloc((nvar+1)*sizeof(*env)+nchr);
+ ep=env;
+ p=(char *)&env[nvar+1];
+
+#define BODY \
+ if((v==var(v->name)) && v->val){ \
+ *ep++=p; \
+ q=v->name; \
+ while(*q) \
+ *p++=*q++; \
+ sep='='; \
+ for(a=v->val;a;a=a->link){ \
+ *p++=sep; \
+ sep='\1'; \
+ q=a->str; \
+ while(*q) \
+ *p++=*q++; \
+ } \
+ *p++='\0'; \
+ }
+
+ for(v=shell->local; v; v=v->link){
+ BODY
+ }
+ for(h=globals; h!=arrend(globals); h++){
+ for(v = *h; v; v=v->link){
+ BODY
+ }
+ }
+#undef BODY
+
+ *ep=0;
+
+ qsort((char *)env, nvar, sizeof ep[0], cmpenv);
+ return env;
+}
+
+void
+initpath(void)
+{
+ Var *v;
+
+ v = globalvar("path");
+ v->update = littlepath;
+
+ v = globalvar("PATH");
+ v->update = bigpath;
+
+ flush(errio);
+ bigpath(v);
+}
+
diff --git a/sys/cmd/rc/wait.c b/sys/cmd/rc/wait.c
new file mode 100644
index 0000000..06f9614
--- /dev/null
+++ b/sys/cmd/rc/wait.c
@@ -0,0 +1,3 @@
+#include "rc.h"
+#include <sys/wait.h>
+
generated by cgit v1.2.1 (git 2.18.0) at 2024-05-17 00:19:10 +0000