Various additions and fixes.

src/lib9/quote.c

@@ -0,0 +1,136 @@
+#include <u.h>
+#include <libc.h>
+
+int	(*doquote)(int);
+
+/* in libfmt */
+extern int __needsquotes(char*, int*);
+extern int __runeneedsquotes(Rune*, int*);
+
+char*
+unquotestrdup(char *s)
+{
+	char *t, *ret;
+	int quoting;
+
+	ret = s = strdup(s);	/* return unquoted copy */
+	if(ret == nil)
+		return ret;
+	quoting = 0;
+	t = s;	/* s is output string, t is input string */
+	while(*t!='\0' && (quoting || (*t!=' ' && *t!='\t'))){
+		if(*t != '\''){
+			*s++ = *t++;
+			continue;
+		}
+		/* *t is a quote */
+		if(!quoting){
+			quoting = 1;
+			t++;
+			continue;
+		}
+		/* quoting and we're on a quote */
+		if(t[1] != '\''){
+			/* end of quoted section; absorb closing quote */
+			t++;
+			quoting = 0;
+			continue;
+		}
+		/* doubled quote; fold one quote into two */
+		t++;
+		*s++ = *t++;
+	}
+	if(t != s)
+		memmove(s, t, strlen(t)+1);
+	return ret;
+}
+
+Rune*
+unquoterunestrdup(Rune *s)
+{
+	Rune *t, *ret;
+	int quoting;
+
+	ret = s = runestrdup(s);	/* return unquoted copy */
+	if(ret == nil)
+		return ret;
+	quoting = 0;
+	t = s;	/* s is output string, t is input string */
+	while(*t!='\0' && (quoting || (*t!=' ' && *t!='\t'))){
+		if(*t != '\''){
+			*s++ = *t++;
+			continue;
+		}
+		/* *t is a quote */
+		if(!quoting){
+			quoting = 1;
+			t++;
+			continue;
+		}
+		/* quoting and we're on a quote */
+		if(t[1] != '\''){
+			/* end of quoted section; absorb closing quote */
+			t++;
+			quoting = 0;
+			continue;
+		}
+		/* doubled quote; fold one quote into two */
+		t++;
+		*s++ = *t++;
+	}
+	if(t != s)
+		memmove(s, t, (runestrlen(t)+1)*sizeof(Rune));
+	return ret;
+}
+
+char*
+quotestrdup(char *s)
+{
+	char *t, *u, *ret;
+	int quotelen;
+	Rune r;
+
+	if(__needsquotes(s, &quotelen) == 0)
+		return strdup(s);
+	
+	ret = malloc(quotelen+1);
+	if(ret == nil)
+		return nil;
+	u = ret;
+	*u++ = '\'';
+	for(t=s; *t; t++){
+		r = *t;
+		if(r == L'\'')
+			*u++ = r;	/* double the quote */
+		*u++ = r;
+	}
+	*u++ = '\'';
+	*u = '\0';
+	return ret;
+}
+
+Rune*
+quoterunestrdup(Rune *s)
+{
+	Rune *t, *u, *ret;
+	int quotelen;
+	Rune r;
+
+	if(__runeneedsquotes(s, &quotelen) == 0)
+		return runestrdup(s);
+	
+	ret = malloc((quotelen+1)*sizeof(Rune));
+	if(ret == nil)
+		return nil;
+	u = ret;
+	*u++ = '\'';
+	for(t=s; *t; t++){
+		r = *t;
+		if(r == L'\'')
+			*u++ = r;	/* double the quote */
+		*u++ = r;
+	}
+	*u++ = '\'';
+	*u = '\0';
+	return ret;
+}