Added string copy function that only copies specified amount of characters

1 files changed, 20 insertions, 0 deletions

diff --git a/str_fns.h b/str_fns.h
new file mode 100644
index 0000000..d580231
--- /dev/null
+++ b/str_fns.h
@@ -0,0 +1,20 @@
+bool str_copy( char *dststr, char *srcstr, size_t max_chars ){
+    if ( max_chars <= 0 )
+        return false;
+    if ( srcstr == NULL )
+        return false;
+    size_t src_len = (size_t)strnlen( srcstr, max_chars );
+    if ( src_len <= 0 )
+        return false;
+    bool need_null = false;
+    if ( src_len >= max_chars )
+        need_null = true;
+    size_t copied_chars = 0;
+    for ( ; srcstr[copied_chars] != '\0' && copied_chars < max_chars; copied_chars++ )
+        dststr[copied_chars] = srcstr[copied_chars];
+    if ( need_null )
+        dststr[copied_chars + 1] = '\0';
+    if ( strncmp((const char*)dststr, (const char*)srcstr, max_chars) != 0 )
+        return false;
+    return true;
+}