argpar: sync with upstream - adjust to iterator API

[lttng-tools.git] / src / common / string-utils / string-utils.c

diff --git a/src/common/string-utils/string-utils.c b/src/common/string-utils/string-utils.c
index 526604d14e42a6f0d907fab86676ca2f2435e46f..80b9f73504f8cfba664429a87a721a113b9ebda1 100644 (file)
--- a/src/common/string-utils/string-utils.c
+++ b/src/common/string-utils/string-utils.c
@@ -7,10 +7,12 @@
 
 #define _LGPL_SOURCE
 #include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
 #include <stdbool.h>
 #include <assert.h>
 #include <errno.h>
+#include <stdarg.h>
 
 #include "string-utils.h"
 #include "../macros.h"
@@ -392,3 +394,50 @@ int strutils_append_str(char **s, const char *append)
        free(old);
        return 0;
 }
+
+LTTNG_HIDDEN
+int strutils_appendf(char **s, const char *fmt, ...)
+{
+       char *new_str;
+       size_t oldlen = (*s) ? strlen(*s) : 0;
+       int ret;
+       va_list args;
+
+       /* Compute length of formatted string we append. */
+       va_start(args, fmt);
+       ret = vsnprintf(NULL, 0, fmt, args);
+       va_end(args);
+
+       if (ret == -1) {
+               goto end;
+       }
+
+       /* Allocate space for old string + new string + \0. */
+       new_str = calloc(oldlen + ret + 1, 1);
+       if (!new_str) {
+               ret = -ENOMEM;
+               goto end;
+       }
+
+       /* Copy old string, if there was one. */
+       if (oldlen) {
+               strcpy(new_str, *s);
+       }
+
+       /* Format new string in-place. */
+       va_start(args, fmt);
+       ret = vsprintf(&new_str[oldlen], fmt, args); 
+       va_end(args);
+
+       if (ret == -1) {
+               ret = -1;
+               goto end;
+       }
+
+       free(*s);
+       *s = new_str;
+       new_str = NULL;
+
+end:
+       return ret;
+}