argpar: sync with upstream - adjust to iterator API

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

diff --git a/src/common/string-utils/string-utils.cpp b/src/common/string-utils/string-utils.cpp
index 8dcc6b2aae9ce9fab7b3beeefbea0b495fc15db4..d23cf794cb34b0edb7da097f4393b4bced4fb8bb 100644 (file)
--- a/src/common/string-utils/string-utils.cpp
+++ b/src/common/string-utils/string-utils.cpp
@@ -7,11 +7,13 @@
 
 #define _LGPL_SOURCE
 #include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
 #include <stdbool.h>
 #include <type_traits>
 #include <assert.h>
 #include <errno.h>
+#include <stdarg.h>
 
 #include "string-utils.h"
 #include "../macros.h"
@@ -395,3 +397,49 @@ int strutils_append_str(char **s, const char *append)
        free(old);
        return 0;
 }
+
+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 = (char *) zmalloc(oldlen + ret + 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;
+}