pgm_save: Check whether file could be opened

3 files changed, 11 insertions, 5 deletions

diff --git a/src/advtime.c b/src/advtime.c
index e4cd9a9..402da31 100644
--- a/src/advtime.c
+++ b/src/advtime.c
@@ -113,8 +113,10 @@ main(int argc, char **argv)
 		if (diff > 40.0) {
 			snprintf(filename, BUFSIZ, "img/%04i.pgm", i);
 			frame_mix(frame_a, frame_b);
-			pgm_save(frame_a->data, frame_a->stride, frame_a->width,
-				 frame_a->height, filename);
+			if (pgm_save(frame_a->data, frame_a->stride,
+				     frame_a->width, frame_a->height,
+				     filename) < 0)
+				exit(EXIT_FAILURE);
 		}
 
 		printf("\n");
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
diff --git a/src/util.h b/src/util.h
index 8e0503a..bcc2828 100644
--- a/src/util.h
+++ b/src/util.h
@@ -1,7 +1,7 @@
 #ifndef _UTIL_H_
 #define _UTIL_H_
 
-void
+int
 pgm_save(unsigned char *buf, int wrap, int xsize, int ysize, char *filename);
 
 /* Store half of frame_a and half of frame_b in frame_a */