make xstrcat() concats a variable number of strings

1 files changed, 44 insertions, 13 deletions

diff --git a/src/xstd.c b/src/xstd.c
index 309412c..907b313 100644
--- a/src/xstd.c
+++ b/src/xstd.c
@@ -1,6 +1,6 @@
 /***
 	This file is part of LockPassword
-	Copyright (C) 2020-2021 Aleksandr D. Goncharov (Joursoir) <chat@joursoir.net>
+	Copyright (C) 2020-2025 Aleksandr D. Goncharov (Joursoir) <chat@joursoir.net>
 
 	This program is free software: you can redistribute it and/or modify
 	it under the terms of the GNU General Public License as published by
@@ -16,22 +16,53 @@
 	along with this program.  If not, see <https://www.gnu.org/licenses/>.
 ***/
 
+#include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "xstd.h"
 
-char *xstrcat(const char *first, const char *second,
-	const char *delimiter)
+char *xstrcat(const char *first, ...)
 {
-	size_t size = strlen(first) + strlen(second) + 1;
-	if(delimiter)
-		size += strlen(delimiter);
-	char *res = malloc(size * sizeof(char));
-	strcpy(res, first);
-	if(delimiter)
-		strcat(res, delimiter);
-	strcat(res, second);
-	return res;
-}
+    va_list args;
+    const char *s;
+    size_t total_len = 0;
+    size_t len;
+
+    // 1. Calculate the total length required
+    if (first != NULL) {
+        total_len += strlen(first);
+    }
+
+    va_start(args, first);
+    while ((s = va_arg(args, const char *)) != NULL) {
+        total_len += strlen(s);
+    }
+    va_end(args);
+
+    // 2. Allocate memory for the concatenated string
+    char *result = malloc(total_len + 1);
+    if (result == NULL) {
+        return NULL;
+    }
 
+    char *ptr = result;
+
+    // 3. Copy the first string and then the rest of the strings
+    if (first != NULL) {
+        len = strlen(first);
+        memcpy(ptr, first, len);
+        ptr += len;
+    }
+
+    va_start(args, first);
+    while ((s = va_arg(args, const char *)) != NULL) {
+        len = strlen(s);
+        memcpy(ptr, s, len);
+        ptr += len;
+    }
+    va_end(args);
+
+    *ptr = '\0';
+    return result;
+}