1 files changed, 6 insertions, 2 deletions
diff --git a/src/util.c b/src/util.c
index 9ab6e25..d9c8f35 100644
--- a/src/util.c
+++ b/src/util.c
@@ -3,17 +3,21 @@
 #include "video_decode.h"
 #include "util.h"
 
-void
+int
 pgm_save(unsigned char *buf, int wrap, int xsize, int ysize, char *filename)
 {
 	FILE *f;
 	int i;
 
 	f = fopen(filename, "w");
+	if (f == NULL)
+		return -1;
 	fprintf(f, "P5\n%d %d\n%d\n", xsize, ysize, 255);
-	for(i=0; i < ysize; i++)
+	for(i = 0; i < ysize; i++)
 		fwrite(buf + i * wrap, 1, xsize, f);
 	fclose(f);
+
+	return 0;
 }
 
 void