1 files changed, 45 insertions, 0 deletions
diff --git a/src/base/io/getc.c b/src/base/io/getc.c
new file mode 100644
index 0000000..68e1772
--- /dev/null
+++ b/src/base/io/getc.c
@@ -0,0 +1,45 @@
+#include "internal.h"
+
+int
+io·getc(io·Header *io)
+{
+    int i;
+    intptr nr;
+
+loop:
+    i = io->ilen;
+    if(i != 0){
+        io->ilen = i+1;
+        return io->e[i];
+    }
+
+    if(io->state != io·BufRdr){
+        if(io->state == io·BufEnd)
+            io->state = io·BufRdr;
+        return io·BufEof;
+    }
+
+    /*
+     * get next buffer, try to keep io·BufUngets bytes
+     * pre-catenated from the previous read to allow for ungets 
+     */
+    mem·move(io->b-io·BufUngets, io->e-io·BufUngets, io·BufUngets);
+    if(sys·read(io->fd, io->cap, io->b, &nr)){
+        io->state = io·BufNil;
+        return io·BufEof;
+    }
+    if(nr == 0){
+        io->state = io·BufEnd;
+        return io·BufEof;
+    }
+
+    if(nr < io->cap){
+        mem·move(io->e-i-io·BufUngets, io->b-io·BufUngets, i+io·BufUngets);
+        io->g = io->e-i;
+    }
+
+    io->ilen = -i;
+    io->pos += +i;
+
+    goto loop;
+}