blind

commit 26837582379eed2a18350a448f51865f3cd86916
parent 29716cb446111a6c0d82df08d18a1eec848d826c
Author: Mattias Andrée <maandree@kth.se>
Date:   Sun, 29 Jan 2017 21:20:55 +0100

blind-repeat: add support for reading from stdin

Signed-off-by: Mattias Andrée <maandree@kth.se>

Diffstat:
M
man/blind-repeat.1
 | 
15
+++++++++++++--
M
src/blind-repeat.c
 | 
90
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------

2 files changed, 86 insertions(+), 19 deletions(-)
diff --git a/man/blind-repeat.1 b/man/blind-repeat.1
@@ -13,8 +13,6 @@ write the a video to stdout that is a loop of the
 selected video. The looped video is read from the
 selected
 .IR file .
-.I file
-must be a regular file.
 The video will be repeated
 .I count
 times, or until there is no process the reads from
@@ -22,6 +20,19 @@ this process's stdout if
 .B inf
 is selected instead of
 .IR count .
+.P
+.I file
+must be a regular file, or
+.RB ' - '.
+If
+.I file
+is
+.RB ' - ',
+.B blind-repeat
+will read stdin into memory; you are highly discouraged
+from using this unless stdin is a single frame, or known
+to only be a very small number of frames, is it can
+potentially use all of the computer's memory.
 .SH SEE ALSO
 .BR blind (7),
 .BR blind-from-image (1)
diff --git a/src/blind-repeat.c b/src/blind-repeat.c
@@ -10,26 +10,15 @@
 
 USAGE("(count | 'inf') file")
 
-int
-main(int argc, char *argv[])
+static void
+repeat_regular_file(char *file, size_t count, int inf)
 {
 	struct stream stream;
-	size_t count = 0, ptr;
-	ssize_t r;
 	char buf[BUFSIZ];
-	int inf = 0;
-
-	ENOFLAGS(argc != 2);
-
-	if (!strcmp(argv[0], "inf"))
-		inf = 1;
-	else
-		count = etozu_arg("the count", argv[0], 0, SIZE_MAX);
-
-	if (inf)
-		einf_check_fd(STDOUT_FILENO, "<stdout>");
+	size_t ptr;
+	ssize_t r;
 
-	stream.file = argv[1];
+	stream.file = file;
 	stream.fd = eopen(stream.file, O_RDONLY);
 	einit_stream(&stream);
 	if (count > SIZE_MAX / stream.frames)
@@ -51,11 +40,78 @@ main(int argc, char *argv[])
 			if (writeall(STDOUT_FILENO, buf, (size_t)r)) {
 				if (!inf || errno != EPIPE)
 					eprintf("write <stdout>:");
-				return 0;
+				return;
 			}
 		}
 	}
 
 	close(stream.fd);
+}
+
+static void
+repeat_stdin(size_t count, int inf)
+{
+	struct stream stream;
+	char *buf;
+	size_t ptr, size;
+	ssize_t r;
+
+	stream.file = "<stdin>";
+	stream.fd = STDIN_FILENO;
+	einit_stream(&stream);
+	if (count > SIZE_MAX / stream.frames)
+		eprintf("%s: video is too long\n", stream.file);
+	stream.frames *= count;
+	fprint_stream_head(stdout, &stream);
+	efflush(stdout, "<stdout>");
+
+	ptr = stream.ptr;
+	size = ptr < BUFSIZ ? BUFSIZ : ptr;
+	buf = emalloc(size);
+	memcpy(buf, stream.buf, ptr);
+
+	for (;;) {
+		if (ptr == size)
+			buf = erealloc(buf, size <<= 1);
+		r = read(STDIN_FILENO, buf + ptr, size - ptr);
+		if (r < 0)
+			eprintf("read <stdout>:");
+		if (r == 0)
+			break;
+		ptr += (size_t)r;
+	}
+
+	while (inf || count--) {
+		if (writeall(STDOUT_FILENO, buf, ptr)) {
+			if (!inf || errno != EPIPE)
+				eprintf("write <stdout>:");
+			return;
+		}
+	}
+
+	free(buf);
+}
+
+int
+main(int argc, char *argv[])
+{
+	size_t count = 0;
+	int inf = 0;
+
+	ENOFLAGS(argc != 2);
+
+	if (!strcmp(argv[0], "inf"))
+		inf = 1;
+	else
+		count = etozu_arg("the count", argv[0], 0, SIZE_MAX);
+
+	if (inf)
+		einf_check_fd(STDOUT_FILENO, "<stdout>");
+
+	if (!strcmp(argv[1], "-"))
+		repeat_stdin(count, inf);
+	else
+		repeat_regular_file(argv[1], count, inf);
+
 	return 0;
 }