Initial revision

src/cmd/mk/rc.c

@@ -0,0 +1,175 @@
+#include	"mk.h"
+
+char	*termchars = "'= \t";	/*used in parse.c to isolate assignment attribute*/
+char	*shflags = "-I";	/* rc flag to force non-interactive mode */
+int	IWS = '\1';		/* inter-word separator in env - not used in plan 9 */
+
+/*
+ *	This file contains functions that depend on rc's syntax.  Most
+ *	of the routines extract strings observing rc's escape conventions
+ */
+
+
+/*
+ *	skip a token in single quotes.
+ */
+static char *
+squote(char *cp)
+{
+	Rune r;
+	int n;
+
+	while(*cp){
+		n = chartorune(&r, cp);
+		if(r == '\'') {
+			n += chartorune(&r, cp+n);
+			if(r != '\'')
+				return(cp);
+		}
+		cp += n;
+	}
+	SYNERR(-1);		/* should never occur */
+	fprint(2, "missing closing '\n");
+	return 0;
+}
+
+/*
+ *	search a string for characters in a pattern set
+ *	characters in quotes and variable generators are escaped
+ */
+char *
+charin(char *cp, char *pat)
+{
+	Rune r;
+	int n, vargen;
+
+	vargen = 0;
+	while(*cp){
+		n = chartorune(&r, cp);
+		switch(r){
+		case '\'':			/* skip quoted string */
+			cp = squote(cp+1);	/* 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.  Only the first is valid for rc. the
+ *	others are just inserted into the receiving buffer.
+ */
+char*
+expandquote(char *s, Rune r, Bufblock *b)
+{
+	if (r != '\'') {
+		rinsert(b, r);
+		return s;
+	}
+
+	while(*s){
+		s += chartorune(&r, s);
+		if(r == '\'') {
+			if(*s == '\'')
+				s++;
+			else
+				return s;
+		}
+		rinsert(b, r);
+	}
+	return 0;
+}
+
+/*
+ *	Input an escaped token.  Possible escape chars are single-quote,
+ *	double-quote and backslash.  Only the first is a valid escape for
+ *	rc; the others are just inserted into the receiving buffer.
+ */
+int
+escapetoken(Biobuf *bp, Bufblock *buf, int preserve, int esc)
+{
+	int c, line;
+
+	if(esc != '\'')
+		return 1;
+
+	line = mkinline;
+	while((c = nextrune(bp, 0)) > 0){
+		if(c == '\''){
+			if(preserve)
+				rinsert(buf, c);
+			c = Bgetrune(bp);
+			if (c < 0)
+				break;
+			if(c != '\''){
+				Bungetrune(bp);
+				return 1;
+			}
+		}
+		rinsert(buf, c);
+	}
+	SYNERR(line); fprint(2, "missing closing %c\n", esc);
+	return 0;
+}
+
+/*
+ *	copy a single-quoted string; s points to char after opening quote
+ */
+static char *
+copysingle(char *s, Bufblock *buf)
+{
+	Rune r;
+
+	while(*s){
+		s += chartorune(&r, s);
+		rinsert(buf, r);
+		if(r == '\'')
+			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 == '\'')				/* copy quoted string */
+		return copysingle(s, buf);
+
+	if(q != '`')				/* not quoted */
+		return s;
+
+	while(*s){				/* copy backquoted string */
+		s += chartorune(&q, s);
+		rinsert(buf, q);
+		if(q == '}')
+			break;
+		if(q == '\'')
+			s = copysingle(s, buf);	/* copy quoted string */
+	}
+	return s;
+}