bmp_logo: Check return value of fread()
Add basic error handling to fread() function calls. This prevents
compililation warnings such as:
bmp_logo.c: In function ‘main’:
bmp_logo.c:71: warning: ignoring return value of ‘fread’, declared with
attribute warn_unused_result
...
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/tools/bmp_logo.c b/tools/bmp_logo.c
index 98be617..e8dd8c8 100644
--- a/tools/bmp_logo.c
+++ b/tools/bmp_logo.c
@@ -40,6 +40,16 @@
fgetc (fp);
}
+__attribute__ ((__noreturn__))
+int error (char * msg, FILE *fp)
+{
+ fprintf (stderr, "ERROR: %s\n", msg);
+
+ fclose (fp);
+
+ exit (EXIT_FAILURE);
+}
+
int main (int argc, char *argv[])
{
int i, x;
@@ -58,23 +68,25 @@
exit (EXIT_FAILURE);
}
- if (fgetc (fp) != 'B' || fgetc (fp) != 'M') {
- fprintf (stderr, "%s is not a bitmap file.\n", argv[1]);
- exit (EXIT_FAILURE);
- }
+ if (fgetc (fp) != 'B' || fgetc (fp) != 'M')
+ error ("Input file is not a bitmap", fp);
/*
* read width and height of the image, and the number of colors used;
* ignore the rest
*/
skip_bytes (fp, 8);
- fread (&data_offset, sizeof (uint16_t), 1, fp);
+ if (fread (&data_offset, sizeof (uint16_t), 1, fp) != 1)
+ error ("Couldn't read bitmap data offset", fp);
skip_bytes (fp, 6);
- fread (&b->width, sizeof (uint16_t), 1, fp);
+ if (fread (&b->width, sizeof (uint16_t), 1, fp) != 1)
+ error ("Couldn't read bitmap width", fp);
skip_bytes (fp, 2);
- fread (&b->height, sizeof (uint16_t), 1, fp);
+ if (fread (&b->height, sizeof (uint16_t), 1, fp) != 1)
+ error ("Couldn't read bitmap height", fp);
skip_bytes (fp, 22);
- fread (&n_colors, sizeof (uint16_t), 1, fp);
+ if (fread (&n_colors, sizeof (uint16_t), 1, fp) != 1)
+ error ("Couldn't read bitmap colors", fp);
skip_bytes (fp, 6);
/*
@@ -108,11 +120,8 @@
DEFAULT_CMAP_SIZE);
/* allocate memory */
- if ((b->data = (uint8_t *)malloc(b->width * b->height)) == NULL) {
- fclose (fp);
- printf ("Error allocating memory for file %s.\n", argv[1]);
- exit (EXIT_FAILURE);
- }
+ if ((b->data = (uint8_t *)malloc(b->width * b->height)) == NULL)
+ error ("Error allocating memory for file", fp);
/* read and print the palette information */
printf ("unsigned short bmp_logo_palette[] = {\n");