X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fstring-utils%2Fstring-utils.cpp;fp=src%2Fcommon%2Fstring-utils%2Fstring-utils.cpp;h=d23cf794cb34b0edb7da097f4393b4bced4fb8bb;hp=8dcc6b2aae9ce9fab7b3beeefbea0b495fc15db4;hb=d50d200af8d01f4b58a14e384cabd46b1afb4817;hpb=411b31544f22b773b4aad6cdb81faa81dc05e641

diff --git a/src/common/string-utils/string-utils.cpp b/src/common/string-utils/string-utils.cpp
index 8dcc6b2aa..d23cf794c 100644
--- 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;
+}