libsemanage: simplify string utilities functions

Use string functions from C standard library instead of ustr. This makes
the code simpler and make utilities.c no longer depend on ustr library.

This changes how semanage_split() behaves when delim is not empty (NULL
or "") and the input string contains several successive delimiters:
semanage_split("foo::::bar", ":") returned "bar" and now returns ":bar".
This would not have any impact in the current code as semanage_split()
is only called with delim="=" (through semanage_findval(), in
libsemanage/src/genhomedircon.c), in order to split a "key=value"
statement.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>

libsemanage/src/utilities.c

@@ -26,7 +26,6 @@
 #include <string.h>
 #include <sys/types.h>
 #include <assert.h>
-#include <ustr.h>
 
 #define TRUE 1
 #define FALSE 0
@@ -74,64 +73,32 @@ char *semanage_split_on_space(const char *str)
 {
 	/* as per the man page, these are the isspace() chars */
 	const char *seps = "\f\n\r\t\v ";
-	size_t slen = strlen(seps);
-	size_t off = 0, rside_len = 0;
-	char *retval = NULL;
-	Ustr *ustr = USTR_NULL, *temp = USTR_NULL;
+	size_t off = 0;
 
 	if (!str)
-		goto done;
-	if (!(ustr = ustr_dup_cstr(str)))
-		goto done;
-	temp =
-	    ustr_split_spn_chrs(ustr, &off, seps, slen, USTR_NULL,
-				USTR_FLAG_SPLIT_DEF);
-	if (!temp)
-		goto done;
-	/* throw away the left hand side */
-	ustr_sc_free(&temp);
-
-	rside_len = ustr_len(ustr) - off;
-	temp = ustr_dup_subustr(ustr, off + 1, rside_len);
-	if (!temp)
-		goto done;
-	retval = strdup(ustr_cstr(temp));
-	ustr_sc_free(&temp);
+		return NULL;
 
-      done:
-	ustr_sc_free(&ustr);
-	return retval;
+	/* skip one token and the spaces before and after it */
+	off = strspn(str, seps);
+	off += strcspn(str + off, seps);
+	off += strspn(str + off, seps);
+	return strdup(str + off);
 }
 
 char *semanage_split(const char *str, const char *delim)
 {
-	Ustr *ustr = USTR_NULL, *temp = USTR_NULL;
-	size_t off = 0, rside_len = 0;
-	char *retval = NULL;
+	char *retval;
 
 	if (!str)
-		goto done;
+		return NULL;
 	if (!delim || !(*delim))
 		return semanage_split_on_space(str);
-	ustr = ustr_dup_cstr(str);
-	temp =
-	    ustr_split_cstr(ustr, &off, delim, USTR_NULL, USTR_FLAG_SPLIT_DEF);
-	if (!temp)
-		goto done;
-	/* throw away the left hand side */
-	ustr_sc_free(&temp);
-
-	rside_len = ustr_len(ustr) - off;
 
-	temp = ustr_dup_subustr(ustr, off + 1, rside_len);
-	if (!temp)
-		goto done;
-	retval = strdup(ustr_cstr(temp));
-	ustr_sc_free(&temp);
+	retval = strstr(str, delim);
+	if (retval == NULL)
+		return NULL;
 
-      done:
-	ustr_sc_free(&ustr);
-	return retval;
+	return strdup(retval + strlen(delim));
 }
 
 int semanage_list_push(semanage_list_t ** list, const char *data)