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authorFRIGN <dev@frign.de>2016-01-04 19:17:03 +0100
committerFRIGN <dev@frign.de>2016-01-04 19:17:03 +0100
commit6ad3875caa041b3ea716c3b24bee14e748b5c7ff (patch)
tree76885edd4951fbb7ef63df55471b1500f2117a98 /png2ff.c
parentd8e77e37dd74d4835977209c3cd57fba3307f6a8 (diff)
Add stricter and clearer error-checking in png2ff and ff2png
As known from sbase, we want to manually flush stdout to see if all data has been passed on.
Diffstat (limited to 'png2ff.c')
-rw-r--r--png2ff.c23
1 files changed, 18 insertions, 5 deletions
diff --git a/png2ff.c b/png2ff.c
index 0835d34..4f4fc83 100644
--- a/png2ff.c
+++ b/png2ff.c
@@ -1,6 +1,7 @@
/* See LICENSE file for copyright and license details. */
#include <arpa/inet.h>
+#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
@@ -13,7 +14,7 @@ main(int argc, char *argv[])
png_structp png_struct_p;
png_infop png_info_p;
png_bytepp png_row_p;
- int depth, color;
+ int depth, color, ret = 0;
uint32_t width, height, png_row_len, tmp32, r, i;
uint16_t tmp16;
@@ -28,7 +29,7 @@ main(int argc, char *argv[])
png_info_p = png_create_info_struct(png_struct_p);
if (!png_struct_p || !png_info_p) {
- fprintf(stderr, "failed to initialize libpng\n");
+ fprintf(stderr, "%s: failed to initialize libpng\n", argv[0]);
return 1;
}
if (setjmp(png_jmpbuf(png_struct_p)))
@@ -48,7 +49,7 @@ main(int argc, char *argv[])
png_row_p = png_get_rows(png_struct_p, png_info_p);
/* write header */
- fprintf(stdout, "farbfeld");
+ fputs("farbfeld", stdout);
tmp32 = htonl(width);
fwrite(&tmp32, sizeof(uint32_t), 1, stdout);
tmp32 = htonl(height);
@@ -75,11 +76,23 @@ main(int argc, char *argv[])
}
break;
default:
- fprintf(stderr, "format error\n");
+ fprintf(stderr, "%s: format error\n", argv[0]);
return 1;
}
png_destroy_read_struct(&png_struct_p, &png_info_p, NULL);
- return 0;
+ /* flush output */
+ if (fflush(stdout)) {
+ fprintf(stderr, "%s: fflush stdout: ", argv[0]);
+ perror(NULL);
+ ret = 1;
+ }
+ if (fclose(stdout) && !ret) {
+ fprintf(stderr, "%s: fclose stdout: ", argv[0]);
+ perror(NULL);
+ ret = 1;
+ }
+
+ return ret;
}