lel

commit 08c8ffa8fbf6f600099e6e2dc9c5af55daf094e6
parent 53b38e0a1a143a7395e1bdf919be2f6b689c94c4
Author: Jacob R. Edwards <jacobouno@protonmail.com>
Date:   Sun, 18 Apr 2021 02:51:49 -0700

Simplify error handling

Rework the die function to simply take a char * and use errno to
describe errors allowing a single error message to be used for
multiple different errors (see loadimg).

Diffstat:
M
lel.c
 | 
45
++++++++++++++++++++++-----------------------

1 file changed, 22 insertions(+), 23 deletions(-)
diff --git a/lel.c b/lel.c
@@ -56,25 +56,28 @@ static int winx, winy, reqwinwidth = 320, reqwinheight = 240;
 static float zoominc = 0.25;
 
 static void
-die(const char *fmt, ...)
+edie(int e, char *s)
 {
-	va_list ap;
-
-	va_start(ap, fmt);
-	vfprintf(stderr, fmt, ap);
-	va_end(ap);
-
-	if (fmt[0] && fmt[strlen(fmt) - 1] == ':') {
-		fputc(' ', stderr);
-		perror(NULL);
-	}
+	fputs(getprogname(), stderr);
+	if (s)
+		fprintf(stderr, ": %s", s);
+	if (e)
+		fprintf(stderr, ": %s", strerror(e));
+	fputs(".\n", stderr);
 	exit(1);
 }
 
 static void
+die(char *s)
+{
+	edie(errno, s);
+}
+
+static void
 usage(void)
 {
-	die("usage: %s [-afv] [file...]\n", getprogname());
+	fprintf(stderr, "usage: %s [-afv] [file...]\n", getprogname());
+	exit(1);
 }
 
 static int
@@ -84,6 +87,7 @@ ff_open(struct img *img, FILE *fp)
 
 	if (img->state & LOADED)
 		return 0;
+	errno = EFTYPE;
 
 	if (fread(hdr, sizeof(*hdr), 4, fp) != 4)
 		return -1;
@@ -97,9 +101,9 @@ ff_open(struct img *img, FILE *fp)
 		return -1;
 
 	if (!(img->buf = malloc(img->width * img->height * 4)))
-		die("malloc:");
+		die("malloc");
 
-	return 0;
+	return errno = 0;
 }
 
 static int
@@ -118,7 +122,8 @@ ff_read(struct img *img, FILE *fp)
 	for (off = 0, i = 0; i < img->height; ++i) {
 		if (fread(row, 1, (size_t)row_len, fp) != (size_t)row_len) {
 			free(row);
-			die("unexpected EOF or row-skew at %d\n", i);
+			errno = EFTYPE;
+			return -1;
 		}
 		for (j = 0; j < row_len / 2; j += 4, off += 4) {
 			img->buf[off]     = row[j];
@@ -165,14 +170,8 @@ loadimg(void)
 	FILE *fp;
 
 	fp = fopen(imgs[img.index], "rb");
-	if (fp == NULL)
-		die("open %s\n", imgs[img.index]);
-	if (ff_open(&img, fp))
-		die("can't open image (invalid format?)\n");
-	if (ff_read(&img, fp))
-		die("can't read image\n");
-	if (fclose(fp) != 0)
-		die("close %s\n", imgs[img.index]);
+	if (fp == NULL || ff_open(&img, fp) || ff_read(&img, fp) || fclose(fp))
+		die(imgs[img.index]);
 
 	reqwinwidth = img.width;
 	reqwinheight = img.height;