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 --- tools/bmp_logo.c | 35 ++++++++++++++++++++++------------- 1 files changed, 22 insertions(+), 13 deletions(-)
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 @@ void skip_bytes (FILE *fp, int n) 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 @@ int main (int argc, char *argv[]) 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 @@ int main (int argc, char *argv[]) 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");