Adding FIFO/pipe support ref. #5

.github/README.md

@@ -21,6 +21,8 @@ version and further details on sxiv, how to install it and how it works.
 
 ### Changelog:
 
+2021-09-07 - Added the fifo patch
+
 2021-06-11 - Added the alpha patch
 
 2021-06-10 - Added the "allow escape key in external key handler" patch (for the lack of a better
@@ -62,6 +64,9 @@ version and further details on sxiv, how to install it and how it works.
    - [ewmh-wm-client-machine](https://github.com/muennich/sxiv/pull/403)
       - sets the WM_CLIENT_MACHINE X property
 
+   - [fifo](https://github.com/muennich/sxiv/pull/369)
+      - adds support for pipe-based redirection for sxiv
+
    - [image-mode-cycle](https://github.com/i-tsvetkov/sxiv-patches)
       - adds the ability to cycle when viewing multiple images
 

Makefile

@@ -19,10 +19,10 @@ HAVE_LIBEXIF = 1
 #xrender = -lXrender
 
 # Uncomment to enable SVG support / SVG_IMAGE_SUPPORT_PATCH
-#svglibs = `pkg-config --cflags --libs librsvg-2.0 cairo`
+svglibs = `pkg-config --cflags --libs librsvg-2.0 cairo`
 
 # Uncomment to enable WebP support / WEBP_IMAGE_SUPPORT_PATCH
-#webplibs = -lwebpdemux -lwebp
+webplibs = -lwebpdemux -lwebp
 
 # Uncomment to enable libcurl support / LIBCURL_PATCH
 #curllibs = -lcurl

image.c

@@ -575,7 +575,11 @@ Imlib_Image img_open(const fileinfo_t *file)
 	    stat(file->path, &st) == 0 && S_ISREG(st.st_mode))
 	{
 		#if WEBP_IMAGE_SUPPORT_PATCH
+		#if FIFO_PATCH
+		if (im == NULL && !strstr(file->name, "/proc/") && strcmp(file->name, "/dev/stdin"))
+		#else
 		if (im == NULL)
+		#endif // FIFO_PATCH
 			im = load_webp_firstframe_im(file);
 		#endif // WEBP_IMAGE_SUPPORT_PATCH
 

main.c

@@ -67,10 +67,10 @@ int filecnt, fileidx;
 int alternate;
 int markcnt;
 int markidx;
-#if LIBCURL_PATCH
+#if LIBCURL_PATCH || FIFO_PATCH
 char **rmfiles;
 int rmcnt, rmidx;
-#endif // LIBCURL_PATCH
+#endif // LIBCURL_PATCH | FIFO_PATCH
 
 int prefix;
 bool extprefix;
@@ -115,9 +115,9 @@ CLEANUP void tmp_unlink(char **rmfiles, int n) {
 
 void cleanup(void)
 {
-	#if LIBCURL_PATCH
+	#if LIBCURL_PATCH || FIFO_PATCH
 	tmp_unlink(rmfiles, rmidx);
-	#endif // LIBCURL_PATCH
+	#endif // LIBCURL_PATCH | FIFO_PATCH
 	img_close(&img, false);
 	arl_cleanup(&arl);
 	tns_free(&tns);
@@ -130,18 +130,43 @@ void internal_check_add_file(char *filename, char *url, bool given)
 void check_add_file(char *filename, bool given)
 #endif // LIBCURL_PATCH
 {
-	char *path;
+	char *path = NULL;
+	#if FIFO_PATCH
+	struct stat st;
+	bool rm = false;
+	#endif // FIFO_PATCH
 
 	if (*filename == '\0')
 		return;
 
+	#if FIFO_PATCH
+	if (access(filename, R_OK) == 0 && stat(filename, &st) == 0) {
+		switch (st.st_mode & S_IFMT) {
+		case S_IFREG:
+			path = realpath(filename, NULL);
+			break;
+
+		case S_IFIFO:
+			path = tmp_pipe_drain(filename);
+			rm = true;
+			break;
+		}
+	}
+
+	if (path == NULL) {
+		if (given)
+			error(0, errno, "%s", filename);
+		return;
+	}
+	#else
 	if (access(filename, R_OK) < 0 ||
 	    (path = realpath(filename, NULL)) == NULL)
 	{
 		if (given)
 			error(0, errno, "%s", filename);
 		return;
 	}
+	#endif // FIFO_PATCH
 
 	if (fileidx == filecnt) {
 		filecnt *= 2;
@@ -166,6 +191,18 @@ void check_add_file(char *filename, bool given)
 	if (given)
 		files[fileidx].flags |= FF_WARN;
 	fileidx++;
+
+	#if FIFO_PATCH
+	if (rm) {
+		if (rmidx == rmcnt) {
+			rmcnt *= 2;
+			rmfiles = erealloc(rmfiles, rmcnt * sizeof(char*));
+			memset(&rmfiles[rmcnt/2], 0, rmcnt/2 * sizeof(char*));
+		}
+
+		rmfiles[rmidx++] = path;
+	}
+	#endif // FIFO_PATCH
 }
 
 #if LIBCURL_PATCH
@@ -961,11 +998,12 @@ int main(int argc, char **argv)
 	files = emalloc(filecnt * sizeof(*files));
 	memset(files, 0, filecnt * sizeof(*files));
 	fileidx = 0;
-	#if LIBCURL_PATCH
+
+	#if LIBCURL_PATCH || FIFO_PATCH
 	rmcnt = 16;
 	rmfiles = emalloc(rmcnt * sizeof(char*));
 	rmidx = 0;
-	#endif // LIBCURL_PATCH
+	#endif // LIBCURL_PATCH | FIFO_PATCH
 
 	if (options->from_stdin) {
 		n = 0;

patches.def.h

@@ -62,6 +62,20 @@
  */
 #define EWMH_WM_CLIENT_MACHINE 0
 
+/* Adds support for pipe-based redirection for sxiv.
+ *
+ * Example commands:
+ *   $ sxiv <(curl -s https://i.imgur.com/JdfIbt4g.png) <(curl -s https://i.imgur.com/WwcW92d.png)
+ *   $ curl -s https://i.imgur.com/JdfIbt4g.png | sxiv /dev/stdin
+ *
+ * This is not possible out of the box because FIFO/pipe files are not seekable which breaks
+ * things. The patch works around this by draining the pipe to a temporary file which is displayed
+ * and unlinked on exit.
+ *
+ * https://github.com/muennich/sxiv/pull/369
+ */
+#define FIFO_PATCH 0
+
 /* Adds the ability to cycle when viewing multiple images.
  * https://github.com/i-tsvetkov/sxiv-patches
  */

sxiv.h

@@ -411,6 +411,10 @@ int r_opendir(r_dir_t*, const char*, bool);
 int r_closedir(r_dir_t*);
 char* r_readdir(r_dir_t*, bool);
 int r_mkdir(char*);
+#if FIFO_PATCH
+char* tmp_pipe_drain(char*);
+CLEANUP void tmp_unlink(char**, int);
+#endif // FIFO_PATCH
 
 
 /* window.c */

util.c

@@ -211,3 +211,37 @@ int r_mkdir(char *path)
 	return 0;
 }
 
+#if FIFO_PATCH
+char *tmp_pipe_drain(char *pipe)
+{
+	int n;
+	char buf[1024];
+	char *path = emalloc(PATH_MAX);
+	int fd;
+
+	snprintf(path, PATH_MAX, "/tmp/sxiv-XXXXXX");
+	if ((fd = mkstemp(path)) < 0) {
+		free(path);
+		return NULL;
+	}
+
+	FILE *src = fopen(pipe, "rb");
+	FILE *dst = fdopen(fd, "wb");
+
+	while ((n = fread(buf, sizeof(char), sizeof(buf), src)) > 0) {
+		if (fwrite(buf, sizeof(char), n, dst) < n) {
+			free(path);
+			return NULL;
+		}
+	}
+
+	fclose(dst);
+	fclose(src);
+	return path;
+}
+
+CLEANUP void tmp_unlink(char **rmfiles, int n) {
+	while (n--)
+		unlink(rmfiles[n]);
+}
+#endif // FIFO_PATCH