adding ft_strjoin_static

Makefile

@@ -54,6 +54,7 @@ SRCS	=	ft_memset.c \
 			ft_strncpy.c \
 			ft_strstr.c \
 			ft_strjoinfree.c \
+			ft_strjoin_static.c \
 			ft_strclr.c \
 			ft_strdel.c \
 			ft_strequ.c \

includes/libft.h

@@ -49,6 +49,7 @@ char *ft_strdup(const char *s1);
 
 char *ft_substr(char const *s, unsigned int start, size_t len);
 char *ft_strjoin(char const *s1, char const *s2);
+size_t ft_strjoin_static(char *dst, size_t dst_size, const char **srcs, size_t n);
 char *ft_strtrim(char const *s1, char const *set);
 char **ft_split(char const *s, char c);
 char *ft_itoa(long int n);

srcs/ft_strjoin_static.c

@@ -0,0 +1,42 @@
+#include "libft.h"
+
+/**
+ * Concatenates an array of strings into a pre-allocated destination buffer.
+ *
+ * @param dst      Destination buffer.
+ * @param dst_size Size of the destination buffer (including space for null terminator).
+ * @param srcs     Array of source strings to concatenate.
+ * @param n        Number of strings in `srcs`.
+ * @return         The total length of the concatenated string (excluding null terminator),
+ *                 or 0 if the buffer is too small.
+ * @note           The caller must ensure `dst_size > 0`. If the buffer is too small,
+ *                 the function returns 0 and `dst` is set to an empty string.
+ */
+
+size_t ft_strjoin_static(char *dst, size_t dst_size, const char **srcs, size_t n)
+{
+    // Calculate total length needed
+    size_t total_len = 0;
+    for (size_t i = 0; i < n; i++)
+    {
+        total_len += ft_strlen(srcs[i]);
+    }
+
+    // Check if buffer is large enough (include space for '\0')
+    if (total_len + 1 > dst_size)
+    {
+        dst[0] = '\0';
+        return 0;
+    }
+
+    // Copy strings
+    char *ptr = dst;
+    for (size_t i = 0; i < n; i++)
+    {
+        size_t len = ft_strlen(srcs[i]);
+        ft_memcpy(ptr, srcs[i], len);
+        ptr += len;
+    }
+    *ptr = '\0';
+    return total_len;
+}