From af3fa90e8bb41c306c5fe2d2cf105db6bbabd1d9 Mon Sep 17 00:00:00 2001
From: Nicholas Noll <nbnoll@eml.cc>
Date: Tue, 19 Oct 2021 10:53:45 -0700
Subject: Feat: word operators and more robust crashing

Added the length and concatenate operators.
Slightly improved the robustness on syntax errors.
---
 sys/cmd/rc/lex.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

(limited to 'sys/cmd/rc/lex.c')

diff --git a/sys/cmd/rc/lex.c b/sys/cmd/rc/lex.c
index b4a2e8c..06737ba 100644
--- a/sys/cmd/rc/lex.c
+++ b/sys/cmd/rc/lex.c
@@ -2,6 +2,7 @@
 #include "parse.h"
 
 static int advance(void);
+
 // -----------------------------------------------------------------------
 // lexer
 
@@ -14,10 +15,14 @@ struct Lexer
 
 static struct Lexer lexer = { .c={0, EOF}, .doprompt=1 };
 
+#define put1(b)        lexer.buf[0] = (b),  lexer.buf[1] = 0;
+#define put2(b0,b1)    lexer.buf[0] = (b0), lexer.buf[1] = (b1), lexer.buf[2] = 0;
+#define put3(b0,b1,b2) lexer.buf[0] = (b0), lexer.buf[1] = (b1), lexer.buf[2] = b2, lexer.buf[3] = 0;
+
 void
 yyerror(const char *msg)
 {
-    print(shell.err, "\nrc:%d: ", runner->line);
+    print(shell.err, "rc:%d: ", runner->line);
 
     if(lexer.buf[0] && lexer.buf[0]!='\n')
         print(shell.err, "%q: ", lexer.buf);
@@ -48,7 +53,6 @@ readc(void)
         exit(1); // XXX: hack for signal handling right now...
 
     c = get(runner->cmd.io);
-
     lexer.doprompt = lexer.doprompt || c=='\n' || c==EOF;
 
     if(c==EOF)
@@ -180,12 +184,25 @@ yylex(void)
     skipws();
     switch(c=advance()){
     case EOF:
+        put3('E','O','F');
         return EOF;
+
     case '&':
-        lexer.buf[0] = '&';
-        lexer.buf[1] = 0;
+        put1('&');
         return '&';
 
+    case '$':
+        if(nextis('#')){
+            put2('$','#');
+            return Tcount;
+        }
+        if(nextis('^')){
+            put2('$','^');
+            return Tflat;
+        }
+        put1('$');
+        return '$';
+
     default:
         ;
     }
-- 
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