--filelist: Support reading from /dev/stdin ("-" as shortcut)

Note that read_filelist used to check if its argument was an image (for people
accidentaly typing "feh -df *" instead of "feh -dF *"); this was removed
because it failed on /dev/stdin.

I might re-add it, but I'm not yet sure about the future of feh's automatic
filelist saving.

4 files changed, 25 insertions, 17 deletions

diff --git a/ChangeLog b/ChangeLog
index ff6f0f4..5eda224 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,7 @@ git HEAD
       better readable
       <https://github.com/derf/feh/issues/60>
     * The --collage option (aka collage mode) is now deprecated
+    * The --filelist option now supports /dev/stdin (or "-" as shortcut)
 
 Tue, 16 Aug 2011 22:48:06 +0200  Daniel Friesel <derf@finalrewind.org>
 
diff --git a/man/feh.pre b/man/feh.pre
index 598231a..a1b7b9b 100644
--- a/man/feh.pre
+++ b/man/feh.pre
@@ -195,12 +195,20 @@ This option is similar to the playlists used by music software.  If
 .Ar file
 exists, it will be read for a list of files to load, in the order they appear.
 The format is a list of image filenames, absolute or relative to the current
-directory, one filename per line.  If
+directory, one filename per line.
+.
+.Pp
+.
+If
 .Ar file
 doesn't exist, it will be created from the internal filelist at the end of a
 viewing session.  This is best used to store the results of complex sorts
 .Pq Cm -Spixels No for example
-for later viewing.  Any changes to the internal filelist
+for later viewing.
+.
+.Pp
+.
+Any changes to the internal filelist
 .Pq such as deleting a file or it being pruned for being unloadable
 will be saved to
 .Ar file
@@ -209,6 +217,15 @@ when
 exits.  You can add files to filelists by specifying them on the commandline
 when also specifying the list.
 .
+.Pp
+.
+If
+.Ar file
+is
+.Qq - ,
+.Nm
+will read the filelist from its standard input.
+.
 .It Cm -e , --font Ar font
 .
 Set global font.  Should be a truetype font, resident in the current directory
diff --git a/src/filelist.c b/src/filelist.c
index 0373504..d83b8df 100644
--- a/src/filelist.c
+++ b/src/filelist.c
@@ -440,7 +440,7 @@ int feh_write_filelist(gib_list * list, char *filename)
 	FILE *fp;
 	gib_list *l;
 
-	if (!list || !filename)
+	if (!list || !filename || !strcmp(filename, "/dev/stdin"))
 		return(0);
 
 	errno = 0;
@@ -467,19 +467,6 @@ gib_list *feh_read_filelist(char *filename)
 	if (!filename)
 		return(NULL);
 
-	/* try and load the given filelist as an image, cowardly refuse to
-	 * overwrite an image with a filelist. (requested by user who did feh -df *
-	 * when he meant feh -dF *, as it overwrote the first image with the
-	 * filelist).
-	 */
-	if (feh_load_image_char(&im1, filename)) {
-		weprintf(
-				"The file you specified as a filelist to read - %s - appears to be an image. Ignoring it (this is a common mistake).\n",
-				filename);
-		opt.filelistfile = NULL;
-		return(NULL);
-	}
-
 	errno = 0;
 	if ((fp = fopen(filename, "r")) == NULL) {
 		/* return quietly, as it's okay to specify a filelist file that doesn't
diff --git a/src/options.c b/src/options.c
index 13aaa95..c5ed85d 100644
--- a/src/options.c
+++ b/src/options.c
@@ -627,7 +627,10 @@ static void feh_parse_option_array(int argc, char **argv, int finalrun)
 			opt.alpha_level = 255 - atoi(optarg);
 			break;
 		case 'f':
-			opt.filelistfile = estrdup(optarg);
+			if (!strcmp(optarg, "-"))
+				opt.filelistfile = estrdup("/dev/stdin");
+			else
+				opt.filelistfile = estrdup(optarg);
 			break;
 		case '0':
 			opt.reload_button = atoi(optarg);