Implement ca_strdup for platforms that lack it natively

Signed-off-by: Lennart Poettering <lennart@poettering.net>

3 files changed, 36 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
index 551073d..2a48177 100644
--- a/configure.ac
+++ b/configure.ac
@@ -139,6 +139,9 @@ AC_CHECK_FUNCS([strerror_r])
 # BSD
 AC_CHECK_FUNCS([lstat])
 
+# GNU
+AC_CHECK_FUNCS([strndup])
+
 #### POSIX threads ####
 
 ACX_PTHREAD
diff --git a/src/malloc.c b/src/malloc.c
index e32cc1b..9592af4 100644
--- a/src/malloc.c
+++ b/src/malloc.c
@@ -58,3 +58,28 @@ char *ca_sprintf_malloc(const char *format, ...) {
             size *= 2;
     }
 }
+
+#ifndef HAVE_STRNDUP
+char *ca_strndup(const char *s, size_t n) {
+    size_t n_avail;
+    char *p;
+
+    if (!s)
+        return NULL;
+
+    if (memchr(s, '\0', n)) {
+        n_avail = strlen(s);
+        if (n_avail > n)
+            n_avail = n;
+    } else
+        n_avail = n;
+
+    if (!(p = ca_new(char, n_avail + 1)))
+        return NULL;
+
+    memcpy(p, s, n_avail);
+    p[n_avail] = '\0';
+
+    return p;
+}
+#endif
diff --git a/src/malloc.h b/src/malloc.h
index 30f0216..6073e03 100644
--- a/src/malloc.h
+++ b/src/malloc.h
@@ -27,11 +27,19 @@
 #include "canberra.h"
 #include "macro.h"
 
+#ifndef PACKAGE
+#error "Please include config.h before including this file!"
+#endif
+
 #define ca_malloc malloc
 #define ca_free free
 #define ca_malloc0(size) calloc(1, (size))
 #define ca_strdup strdup
+#ifdef HAVE_STRNDUP
 #define ca_strndup strndup
+#else
+char *ca_strndup(const char *s, size_t n);
+#endif
 
 void* ca_memdup(const void* p, size_t size);