From 93f54135a8b7f959d2b7873a4ec8f9a5ff2df3b6 Mon Sep 17 00:00:00 2001
From: Neil <neil@sdf.org>
Date: Fri, 11 Jun 2021 20:42:19 -0700
Subject: [PATCH] Tested and improved speed.

---
 readme.md    | 20 +++++++++++++-------
 src/gifbar.c | 15 ++++++++-------
 2 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/readme.md b/readme.md
index 794c77a..bd41f8c 100644
--- a/readme.md
+++ b/readme.md
@@ -1,11 +1,17 @@
-# gifbar #
+# gifbar\.c #
 
-This is a CGI gif percentage (well, per-0xFF) bar using
-hard-coded data and colour-cycling. 
+ * [Description](#user-content-preamble)
+ * [License](#user-content-license)
+
+## <a id = "user-content-preamble" name = "user-content-preamble">Description</a> ##
+
+This is a CGI gif percentage \(well, per\-0xFF\) bar using hard\-coded data and colour\-cycling\. Outputs `image/gif` of the progress bar in nice mottled style\. Usage `gifbar?[0-255]`\.
+
+
+
+## <a id = "user-content-license" name = "user-content-license">License</a> ##
+
+1997, 2007 Neil Edelman, distributed under the terms of the [GNU General Public License 3](https://opensource.org/licenses/GPL-3.0)\.
 
-Usage: gifbar?[0-255]
 
-## License ##
 
-1997, 2007 Neil Edelman, distributed under the terms of
-the [MIT License](https://opensource.org/licenses/MIT).
diff --git a/src/gifbar.c b/src/gifbar.c
index c177767..f1628fa 100644
--- a/src/gifbar.c
+++ b/src/gifbar.c
@@ -1,8 +1,9 @@
 /** @license 1997, 2007 Neil Edelman, distributed under the terms of the
  [GNU General Public License 3](https://opensource.org/licenses/GPL-3.0).
 
- CGI GET a single argument, a number from [0-255]. Outputs `image/gif`
- of the progress bar in nice mottled style. */
+ This is a CGI gif percentage (well, per-0xFF) bar using hard-coded data and
+ colour-cycling. Outputs `image/gif` of the progress bar in nice mottled style.
+ Usage `gifbar?[0-255]`. */
 
 /* I was looking though old code, and the one is genius. I cleaned it up.
  September 3, 2007.
@@ -52,8 +53,8 @@ trailer: (one per data stream)
 #include <string.h> /* strcmp() */
 #include <assert.h>
 
-/** Prints the GIF of `parm` per-`[0, 255]` on `stdout`. */
-static void print_gif(unsigned char parm) {
+/** Prints the GIF of `parm` per-`[0, 255]` on `stdout`. @return Success. */
+static int print_gif(unsigned char parm) {
 	/* Binary `gif` output that I made up with a painting programme; could
 	 replace with anything, make it `00-FF` as it goes across the image. */
 	static unsigned char table[256 * 3];
@@ -284,7 +285,8 @@ static void print_gif(unsigned char parm) {
 	if(fwrite(header, 1, sizeof header, stdout) != sizeof header
 		|| fwrite(table, 1, sizeof table, stdout) != sizeof table
 		|| fwrite(descriptor_data_end, 1, sizeof descriptor_data_end, stdout)
-		!= sizeof descriptor_data_end) perror("stdout");
+		!= sizeof descriptor_data_end) return perror("stdout"), 0;
+	return 1;
 }
 
 int main(void) {
@@ -299,6 +301,5 @@ int main(void) {
 	printf("Content-type: image/gif\n\n");
 	/* May need to set `stdout` to binary mode to avoid line feed translation;
 	 if on Windows? if(setmode(stdout, O_BINARY) == -1) return 1; */
-	print_gif((unsigned char)atoi(env)); /* Don't care ab conversion errors. */
-	return EXIT_SUCCESS;
+	return print_gif((unsigned char)atoi(env)) ? EXIT_SUCCESS : EXIT_FAILURE;
 }