args: Use /etc/kmsfb-manage.conf when no arguments were passed

This patch adds support for a default arguments file. It parses the
given file as commandline arguments. If the file does not exist, the
help is printed.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>

1 files changed, 59 insertions, 5 deletions

diff --git a/src/kmsfb-manage.c b/src/kmsfb-manage.c
index 0fbad75..0edecf7 100644
--- a/src/kmsfb-manage.c
+++ b/src/kmsfb-manage.c
@@ -1276,12 +1276,69 @@ static void usage(const char *prgname)
 	exit(1);
 }
 
+#define MAX_ARGS 256
+
 int main(int argc, char *argv[])
 {
 	int fd;
 	int c;
 	struct drm_resource *res;
 	int err;
+	char **parse_args;
+	char *cmdline;
+	char *cmdlinev[MAX_ARGS];
+
+	if (argc <= 1) {
+		int f;
+		int ret;
+		ssize_t read_bytes;
+		struct stat st;
+		const char *fname = "/etc/kmsfb-manage.conf";
+		char *cmdline_ptr;
+
+		f = open(fname, O_RDONLY);
+		if (f == -1) {
+			fprintf(stderr, "Failed to open '%s' (%s)!\n", fname, strerror(errno));
+			usage(argv[0]);
+			return 1;
+		}
+
+		ret = fstat(f, &st);
+		if (ret) {
+			fprintf(stderr, "Failed to stat '%s' (%s)!\n", fname, strerror(errno));
+			return 1;
+		}
+
+		cmdline = malloc(st.st_size + 1);
+		if (!cmdline) {
+			fprintf(stderr, "Failed to allocate memory to read in default arguments!\n");
+			return 1;
+		}
+
+		read_bytes = read(f, cmdline, st.st_size);
+		close(f);
+		if (read_bytes != st.st_size) {
+			fprintf(stderr, "kmsfb-manage could not read from file!\n");
+			return 1;
+		}
+		cmdline[st.st_size] = '\0';
+
+		cmdlinev[0] = argv[0];
+		argc = 1;
+		cmdline_ptr = strtok(cmdline, " \n\r");
+		while (cmdline_ptr && argc < MAX_ARGS) {
+			cmdlinev[argc] = cmdline_ptr;
+			cmdline_ptr = strtok(NULL, " \n\r");
+			++argc;
+		}
+		if (argc == MAX_ARGS) {
+			fprintf(stderr, "too many arguments (max %d)!\n", MAX_ARGS);
+			return 1;
+		}
+		parse_args = cmdlinev;
+	} else {
+		parse_args = argv;
+	}
 
 	fd = open("/dev/dri/card0", O_RDWR);
 	if (fd < 0) {
@@ -1293,14 +1350,11 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	if (argc == 1)
-		usage(argv[0]);
-
 	drmfd = fd;
 
 	while (1) {
 		int option_index = 0;
-		c = getopt_long(argc, argv, "f:w:o:hsd",
+		c = getopt_long(argc, parse_args, "f:w:o:hsd",
                         long_options, &option_index);
 		if (c == -1)
 			break;
@@ -1329,7 +1383,7 @@ int main(int argc, char *argv[])
 				exit(1);
 			break;
 		case 'h':
-			usage(argv[0]);
+			usage(parse_args[0]);
 			break;
 		case 'd':
 			debug = 1;