lib/mangle: cleanup, add unhexmangle

 * use strchr() rather than for()
 * small refactoring in mangle code
 * add un-hex-mangle

Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 39 insertions, 18 deletions

diff --git a/lib/mangle.c b/lib/mangle.c
index fd0ee993e..e1b48149f 100644
--- a/lib/mangle.c
+++ b/lib/mangle.c
@@ -13,41 +13,40 @@
 #include "mangle.h"
 #include "c.h"
 
-#define isoctal(a) (((a) & ~7) == '0')
+#define isoctal(a)		(((a) & ~7) == '0')
+
+#define from_hex(c)		(isdigit(c) ? c - '0' : tolower(c) - 'a' + 10)
+
+#define is_unwanted_char(x)	(strchr(" \t\n\\", (unsigned int) x) != NULL)
 
-static unsigned char need_escaping[] = { ' ', '\t', '\n', '\\' };
 
 char *mangle(const char *s)
 {
 	char *ss, *sp;
-	size_t n;
 
 	if (!s)
 		return NULL;
 
-	n = strlen(s);
-	ss = sp = malloc(4*n+1);
+	ss = sp = malloc(4 * strlen(s) + 1);
 	if (!sp)
 		return NULL;
 	while(1) {
-		for (n = 0; n < sizeof(need_escaping); n++) {
-			if (*s == need_escaping[n]) {
-				*sp++ = '\\';
-				*sp++ = '0' + ((*s & 0300) >> 6);
-				*sp++ = '0' + ((*s & 070) >> 3);
-				*sp++ = '0' + (*s & 07);
-				goto next;
-			}
+		if (is_unwanted_char(*s)) {
+			*sp++ = '\\';
+			*sp++ = '0' + ((*s & 0300) >> 6);
+			*sp++ = '0' + ((*s & 070) >> 3);
+			*sp++ = '0' + (*s & 07);
+		} else {
+			*sp++ = *s;
+			if (!*s)
+				break;
 		}
-		*sp++ = *s;
-		if (*s == 0)
-			break;
-	next:
 		s++;
 	}
 	return ss;
 }
 
+
 void unmangle_to_buffer(const char *s, char *buf, size_t len)
 {
 	size_t sz = 0;
@@ -70,6 +69,28 @@ void unmangle_to_buffer(const char *s, char *buf, size_t len)
 	*buf = '\0';
 }
 
+void unhexmangle_to_buffer(const char *s, char *buf, size_t len)
+{
+	size_t sz = 0;
+
+	if (!s)
+		return;
+
+	while(*s && sz < len - 1) {
+		if (*s == '\\' && sz + 4 < len - 1 && s[1] == 'x' &&
+		    isxdigit(s[2]) && isxdigit(s[3])) {
+
+			*buf++ = from_hex(s[2]) << 4 | from_hex(s[3]);
+			s += 4;
+			sz += 4;
+		} else {
+			*buf++ = *s++;
+			sz++;
+		}
+	}
+	*buf = '\0';
+}
+
 static inline char *skip_nonspaces(const char *s)
 {
 	while (*s && !(*s == ' ' || *s == '\t'))
@@ -110,7 +131,7 @@ char *unmangle(const char *s, char **end)
 int main(int argc, char *argv[])
 {
 	if (argc < 3) {
-		fprintf(stderr, "usage: %s --mangle | --unmangle <string>\n",
+		fprintf(stderr, "usage: %s --mangle|unmangle <string>\n",
 						program_invocation_short_name);
 		return EXIT_FAILURE;
 	}