Btrfs-progs: allow multi-line command group synopsis

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

9 files changed, 39 insertions, 17 deletions

diff --git a/btrfs.c b/btrfs.c
index 76f725a9..88238d6d 100644
--- a/btrfs.c
+++ b/btrfs.c
@@ -22,8 +22,10 @@
 #include "commands.h"
 #include "version.h"
 
-static const char btrfs_cmd_group_usage[] =
-	"btrfs [--help] [--version] <group> [<group>...] <command> [<args>]";
+static const char * const btrfs_cmd_group_usage[] = {
+	"btrfs [--help] [--version] <group> [<group>...] <command> [<args>]",
+	NULL
+};
 
 static const char btrfs_cmd_group_info[] =
 	"Use --help as an argument for information on a specific group or command.";
@@ -225,7 +227,7 @@ static int handle_options(int *argc, char ***argv)
 		} else {
 			fprintf(stderr, "Unknown option: %s\n", arg);
 			fprintf(stderr, "usage: %s\n",
-				btrfs_cmd_group.usagestr);
+				btrfs_cmd_group.usagestr[0]);
 			exit(129);
 		}
 
diff --git a/cmds-balance.c b/cmds-balance.c
index 5fb2fda9..38a74269 100644
--- a/cmds-balance.c
+++ b/cmds-balance.c
@@ -29,8 +29,11 @@
 
 #include "commands.h"
 
-static const char balance_cmd_group_usage[] =
-	"btrfs [filesystem] balance [<command>] [options] <path>";
+static const char * const balance_cmd_group_usage[] = {
+	"btrfs [filesystem] balance <command> [options] <path>",
+	"btrfs [filesystem] balance <path>",
+	NULL
+};
 
 static const char balance_cmd_group_info[] =
 	"'btrfs filesystem balance' command is deprecated, please use\n"
diff --git a/cmds-device.c b/cmds-device.c
index 51089bae..db625a69 100644
--- a/cmds-device.c
+++ b/cmds-device.c
@@ -39,8 +39,10 @@ struct btrfs_ioctl_vol_args { char name[BTRFS_VOL_NAME_MAX]; };
 static inline int ioctl(int fd, int define, void *arg) { return 0; }
 #endif
 
-static const char device_cmd_group_usage[] =
-	"btrfs device <command> [<args>]";
+static const char * const device_cmd_group_usage[] = {
+	"btrfs device <command> [<args>]",
+	NULL
+};
 
 static const char * const cmd_add_dev_usage[] = {
 	"btrfs device add <device> [<device>...] <path>",
diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index a2efb938..1f53d1cf 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -34,8 +34,10 @@
 #include "commands.h"
 #include "btrfslabel.h"
 
-static const char filesystem_cmd_group_usage[] =
-	"btrfs filesystem [<group>] <command> [<args>]";
+static const char * const filesystem_cmd_group_usage[] = {
+	"btrfs filesystem [<group>] <command> [<args>]",
+	NULL
+};
 
 static const char * const cmd_df_usage[] = {
 	"btrfs filesystem df <path>",
diff --git a/cmds-inspect.c b/cmds-inspect.c
index 6cf565de..2f0228f7 100644
--- a/cmds-inspect.c
+++ b/cmds-inspect.c
@@ -28,8 +28,10 @@
 /* btrfs-list.c */
 char *path_for_root(int fd, u64 root);
 
-static const char inspect_cmd_group_usage[] =
-	"btrfs inspect-internal <command> <args>";
+static const char * const inspect_cmd_group_usage[] = {
+	"btrfs inspect-internal <command> <args>",
+	NULL
+};
 
 static int __ino_to_path_fd(u64 inum, int fd, int verbose, const char *prepend)
 {
diff --git a/cmds-scrub.c b/cmds-scrub.c
index af855baa..c4503f44 100644
--- a/cmds-scrub.c
+++ b/cmds-scrub.c
@@ -40,8 +40,10 @@
 
 #include "commands.h"
 
-static const char scrub_cmd_group_usage[] =
-	"btrfs scrub <command> [options] <path>|<device>";
+static const char * const scrub_cmd_group_usage[] = {
+	"btrfs scrub <command> [options] <path>|<device>",
+	NULL
+};
 
 #define SCRUB_DATA_FILE "/var/lib/btrfs/scrub.status"
 #define SCRUB_PROGRESS_SOCKET_PATH "/var/lib/btrfs/scrub.progress"
diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index 68ebd402..950fa8f0 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -33,8 +33,10 @@
 int list_subvols(int fd, int print_parent, int get_default);
 int find_updated_files(int fd, u64 root_id, u64 oldest_gen);
 
-static const char subvolume_cmd_group_usage[] =
-	"btrfs subvolume <command> <args>";
+static const char * const subvolume_cmd_group_usage[] = {
+	"btrfs subvolume <command> <args>",
+	NULL
+};
 
 /*
  * test if path is a directory
diff --git a/commands.h b/commands.h
index de2c75ca..a303a50d 100644
--- a/commands.h
+++ b/commands.h
@@ -51,7 +51,7 @@ struct cmd_struct {
 };
 
 struct cmd_group {
-	const char *usagestr;
+	const char * const *usagestr;
 	const char *infostr;
 
 	const struct cmd_struct commands[];
diff --git a/help.c b/help.c
index 932bdf26..6d042931 100644
--- a/help.c
+++ b/help.c
@@ -162,9 +162,16 @@ static void usage_command_group_internal(const struct cmd_group *grp, int full,
 
 void usage_command_group(const struct cmd_group *grp, int full, int err)
 {
+	const char * const *usagestr = grp->usagestr;
 	FILE *outf = err ? stderr : stdout;
 
-	fprintf(outf, "usage: %s\n\n", grp->usagestr);
+	if (usagestr && *usagestr) {
+		fprintf(outf, "usage: %s\n", *usagestr++);
+		while (*usagestr)
+			fprintf(outf, "   or: %s\n", *usagestr++);
+	}
+
+	fputc('\n', outf);
 	usage_command_group_internal(grp, full, outf);
 	fputc('\n', outf);