Initial revision
diff --git a/src/cmd/mk/sh.c b/src/cmd/mk/sh.c
new file mode 100644
index 0000000..524167a
--- /dev/null
+++ b/src/cmd/mk/sh.c
@@ -0,0 +1,189 @@
+#include "mk.h"
+
+char *termchars = "\"'= \t"; /*used in parse.c to isolate assignment attribute*/
+char *shflags = 0;
+int IWS = ' '; /* inter-word separator in env */
+
+/*
+ * This file contains functions that depend on the shell's syntax. Most
+ * of the routines extract strings observing the shell's escape conventions.
+ */
+
+
+/*
+ * skip a token in quotes.
+ */
+static char *
+squote(char *cp, int c)
+{
+ Rune r;
+ int n;
+
+ while(*cp){
+ n = chartorune(&r, cp);
+ if(r == c)
+ return cp;
+ if(r == '\\')
+ n += chartorune(&r, cp+n);
+ cp += n;
+ }
+ SYNERR(-1); /* should never occur */
+ fprint(2, "missing closing '\n");
+ return 0;
+}
+/*
+ * search a string for unescaped characters in a pattern set
+ */
+char *
+charin(char *cp, char *pat)
+{
+ Rune r;
+ int n, vargen;
+
+ vargen = 0;
+ while(*cp){
+ n = chartorune(&r, cp);
+ switch(r){
+ case '\\': /* skip escaped char */
+ cp += n;
+ n = chartorune(&r, cp);
+ break;
+ case '\'': /* skip quoted string */
+ case '"':
+ cp = squote(cp+1, r); /* n must = 1 */
+ if(!cp)
+ return 0;
+ break;
+ case '$':
+ if(*(cp+1) == '{')
+ vargen = 1;
+ break;
+ case '}':
+ if(vargen)
+ vargen = 0;
+ else if(utfrune(pat, r))
+ return cp;
+ break;
+ default:
+ if(vargen == 0 && utfrune(pat, r))
+ return cp;
+ break;
+ }
+ cp += n;
+ }
+ if(vargen){
+ SYNERR(-1);
+ fprint(2, "missing closing } in pattern generator\n");
+ }
+ return 0;
+}
+
+/*
+ * extract an escaped token. Possible escape chars are single-quote,
+ * double-quote,and backslash.
+ */
+char*
+expandquote(char *s, Rune esc, Bufblock *b)
+{
+ Rune r;
+
+ if (esc == '\\') {
+ s += chartorune(&r, s);
+ rinsert(b, r);
+ return s;
+ }
+
+ while(*s){
+ s += chartorune(&r, s);
+ if(r == esc)
+ return s;
+ if (r == '\\') {
+ rinsert(b, r);
+ s += chartorune(&r, s);
+ }
+ rinsert(b, r);
+ }
+ return 0;
+}
+
+/*
+ * Input an escaped token. Possible escape chars are single-quote,
+ * double-quote and backslash.
+ */
+int
+escapetoken(Biobuf *bp, Bufblock *buf, int preserve, int esc)
+{
+ int c, line;
+
+ if(esc == '\\') {
+ c = Bgetrune(bp);
+ if(c == '\r')
+ c = Bgetrune(bp);
+ if (c == '\n')
+ mkinline++;
+ rinsert(buf, c);
+ return 1;
+ }
+
+ line = mkinline;
+ while((c = nextrune(bp, 0)) >= 0){
+ if(c == esc){
+ if(preserve)
+ rinsert(buf, c);
+ return 1;
+ }
+ if(c == '\\') {
+ rinsert(buf, c);
+ c = Bgetrune(bp);
+ if(c == '\r')
+ c = Bgetrune(bp);
+ if (c < 0)
+ break;
+ if (c == '\n')
+ mkinline++;
+ }
+ rinsert(buf, c);
+ }
+ SYNERR(line); fprint(2, "missing closing %c\n", esc);
+ return 0;
+}
+
+/*
+ * copy a quoted string; s points to char after opening quote
+ */
+static char *
+copysingle(char *s, Rune q, Bufblock *buf)
+{
+ Rune r;
+
+ while(*s){
+ s += chartorune(&r, s);
+ rinsert(buf, r);
+ if(r == q)
+ break;
+ }
+ return s;
+}
+/*
+ * check for quoted strings. backquotes are handled here; single quotes above.
+ * s points to char after opening quote, q.
+ */
+char *
+copyq(char *s, Rune q, Bufblock *buf)
+{
+ if(q == '\'' || q == '"') /* copy quoted string */
+ return copysingle(s, q, buf);
+
+ if(q != '`') /* not quoted */
+ return s;
+
+ while(*s){ /* copy backquoted string */
+ s += chartorune(&q, s);
+ rinsert(buf, q);
+ if(q == '`')
+ break;
+ if(q == '\'' || q == '"')
+ s = copysingle(s, q, buf); /* copy quoted string */
+ }
+ return s;
+}
