lib: Implement strndup

Signed-off-by: Andrew Opalach <andrew@akon.city>

1 files changed, 12 insertions, 3 deletions

diff --git a/include/al/lib.h b/include/al/lib.h
index 4f03235..ac47896 100644
--- a/include/al/lib.h
+++ b/include/al/lib.h
@@ -75,7 +75,8 @@ void al_malloc_stats(size_t *current, size_t *peak, size_t *total);
 #define al_memset memset
 #define al_bzero bzero
 #define al_strlen strlen
-#define al_strndup strndup
+// strndup is _POSIX_C_SOURCE >= 200809L.
+//#define al_strndup strndup
 #define al_snprintf snprintf
 #define al_vsnprintf vsnprintf
 #define al_fflush fflush
@@ -103,6 +104,15 @@ static inline size_t al_strnlen(const char *s, size_t n)
     return p ? (size_t)(p - s) : n;
 }
 
+static inline char *al_strndup(const char *s, size_t n)
+{
+    size_t len = al_strnlen(s, n);
+    char *ret = al_malloc(len + 1);
+    al_memcpy(ret, s, len);
+    ret[len] = '\0';
+    return ret;
+}
+
 static inline s32 al_printf(const char *fmt, ...)
 {
 #ifdef AL_FORCE_DISABLE_OUTPUT
@@ -229,8 +239,7 @@ AL_UNUSED_FUNCTION_POP
 #define MAX_ALLOC_32 ((INT32_MAX - 1) / 4)
 #endif
 
-// Once a growing allocation expands past this number,
-// only grow in multiples of it.
+// Once a growing allocation expands past this number, only grow in multiples of it.
 extern u32 al_grow_step;
 
 u32 al_default_growing_allocation(void **ptr, u32 prev_size, u32 size,