fuse_parse_cmdline(): do not print help/version text

The current behavior makes it difficult to add help for
additional options. With the change, this becomes a lot easier.

8 files changed, 112 insertions, 62 deletions

diff --git a/example/fuse_lo-plus.c b/example/fuse_lo-plus.c
index 60c2daf..c27f377 100644
--- a/example/fuse_lo-plus.c
+++ b/example/fuse_lo-plus.c
@@ -452,10 +452,21 @@ int main(int argc, char *argv[])
 
 	if (fuse_parse_cmdline(&args, &opts) != 0)
 		return 1;
-	if (opts.show_help || opts.show_version) {
-		ret = 1;
+	if (opts.show_help) {
+		printf("usage: %s [options] <mountpoint>\n\n", argv[0]);
+		fuse_cmdline_help();
+		fuse_lowlevel_help();
+		fuse_mount_help();
+		ret = 0;
+		goto err_out1;
+	} else if (opts.show_version) {
+		printf("FUSE library version %s\n", fuse_pkgversion());
+		fuse_lowlevel_version();
+		fuse_mount_version();
+		ret = 0;
 		goto err_out1;
 	}
+
 	lo.debug = opts.debug;
 	lo.root.next = lo.root.prev = &lo.root;
 	lo.root.fd = open("/", O_PATH);
diff --git a/example/hello_ll.c b/example/hello_ll.c
index 014b8ca..b830cb2 100644
--- a/example/hello_ll.c
+++ b/example/hello_ll.c
@@ -192,8 +192,18 @@ int main(int argc, char *argv[])
 
 	if (fuse_parse_cmdline(&args, &opts) != 0)
 		return 1;
-	if (opts.show_help || opts.show_version) {
-		ret = 1;
+	if (opts.show_help) {
+		printf("usage: %s [options] <mountpoint>\n\n", argv[0]);
+		fuse_cmdline_help();
+		fuse_lowlevel_help();
+		fuse_mount_help();
+		ret = 0;
+		goto err_out1;
+	} else if (opts.show_version) {
+		printf("FUSE library version %s\n", fuse_pkgversion());
+		fuse_lowlevel_version();
+		fuse_mount_version();
+		ret = 0;
 		goto err_out1;
 	}
 
diff --git a/example/timefs1.c b/example/timefs1.c
index cff9545..430e00f 100644
--- a/example/timefs1.c
+++ b/example/timefs1.c
@@ -273,6 +273,15 @@ static void* update_fs(void *data) {
     return NULL;
 }
 
+static void show_help(const char *progname)
+{
+    printf("usage: %s [options] <mountpoint>\n\n", progname);
+    printf("File-system specific options:\n"
+               "    --update-interval=<secs>  Update-rate of file system contents\n"
+               "    --no-notify            Disable kernel notifications\n"
+               "\n");
+}
+
 int main(int argc, char *argv[]) {
     struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
     struct fuse_session *se;
@@ -284,13 +293,26 @@ int main(int argc, char *argv[]) {
                        opt_proc) == -1)
         return 1;
 
-    if (fuse_parse_cmdline(&args, &opts) != 0)
-        return 1;
-    if (opts.show_help || opts.show_version) {
+    if (fuse_parse_cmdline(&args, &opts) != 0) {
         ret = 1;
         goto err_out1;
     }
 
+    if (opts.show_help) {
+        show_help(argv[0]);
+        fuse_cmdline_help();
+        fuse_lowlevel_help();
+        fuse_mount_help();
+        ret = 0;
+        goto err_out1;
+    } else if (opts.show_version) {
+        printf("FUSE library version %s\n", fuse_pkgversion());
+        fuse_lowlevel_version();
+        fuse_mount_version();
+        ret = 0;
+        goto err_out1;
+    }
+
     se = fuse_session_new(&args, &tfs_oper,
                           sizeof(tfs_oper), NULL);
     if (se == NULL)
@@ -324,8 +346,8 @@ err_out3:
 err_out2:
     fuse_session_destroy(se);
 err_out1:
-    free(opts.mountpoint);
     fuse_opt_free_args(&args);
+    free(opts.mountpoint);
 
     return ret ? 1 : 0;
 }
diff --git a/example/timefs2.c b/example/timefs2.c
index 3194230..ea10cc1 100644
--- a/example/timefs2.c
+++ b/example/timefs2.c
@@ -319,6 +319,15 @@ static void* update_fs(void *data) {
     return NULL;
 }
 
+static void show_help(const char *progname)
+{
+    printf("usage: %s [options] <mountpoint>\n\n", progname);
+    printf("File-system specific options:\n"
+               "    --update-interval=<secs>  Update-rate of file system contents\n"
+               "    --no-notify            Disable kernel notifications\n"
+               "\n");
+}
+
 int main(int argc, char *argv[]) {
     struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
     struct fuse_session *se;
@@ -332,8 +341,18 @@ int main(int argc, char *argv[]) {
 
     if (fuse_parse_cmdline(&args, &opts) != 0)
         return 1;
-    if (opts.show_help || opts.show_version) {
-        ret = 1;
+    if (opts.show_help) {
+        show_help(argv[0]);
+        fuse_cmdline_help();
+        fuse_lowlevel_help();
+        fuse_mount_help();
+        ret = 0;
+        goto err_out1;
+    } else if (opts.show_version) {
+        printf("FUSE library version %s\n", fuse_pkgversion());
+        fuse_lowlevel_version();
+        fuse_mount_version();
+        ret = 0;
         goto err_out1;
     }
 
diff --git a/example/timefs3.c b/example/timefs3.c
index 0a52e0f..c04b81c 100644
--- a/example/timefs3.c
+++ b/example/timefs3.c
@@ -253,6 +253,16 @@ static void* update_fs(void *data) {
     return NULL;
 }
 
+static void show_help(const char *progname)
+{
+    printf("usage: %s [options] <mountpoint>\n\n", progname);
+    printf("File-system specific options:\n"
+               "    --timeout=<secs>       Timeout for kernel caches\n"
+               "    --update-interval=<secs>  Update-rate of file system contents\n"
+               "    --no-notify            Disable kernel notifications\n"
+               "\n");
+}
+
 int main(int argc, char *argv[]) {
     struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
     struct fuse_session *se;
@@ -266,8 +276,18 @@ int main(int argc, char *argv[]) {
 
     if (fuse_parse_cmdline(&args, &opts) != 0)
         return 1;
-    if (opts.show_help || opts.show_version) {
-        ret = 1;
+    if (opts.show_help) {
+        show_help(argv[0]);
+        fuse_cmdline_help();
+        fuse_lowlevel_help();
+        fuse_mount_help();
+        ret = 0;
+        goto err_out1;
+    } else if (opts.show_version) {
+        printf("FUSE library version %s\n", fuse_pkgversion());
+        fuse_lowlevel_version();
+        fuse_mount_version();
+        ret = 0;
         goto err_out1;
     }
 
diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h
index a834eba..4c39442 100644
--- a/include/fuse_lowlevel.h
+++ b/include/fuse_lowlevel.h
@@ -1599,6 +1599,12 @@ void fuse_lowlevel_help(void);
  */
 void fuse_mount_help(void);
 
+
+/**
+ * Print available options for `fuse_parse_cmdline()`.
+ */
+void fuse_cmdline_help(void);
+
 /* ----------------------------------------------------------- *
  * Filesystem setup & teardown                                 *
  * ----------------------------------------------------------- */
@@ -1615,21 +1621,14 @@ struct fuse_cmdline_opts {
 
 /**
  * Utility function to parse common options for simple file systems
- * using the low-level API. Available options are listed in `struct
- * fuse_opt fuse_helper_opts[]`. A single non-option argument is
- * treated as the mountpoint. Multiple (or no) non-option arguments
- * will result in an error.
- *
- * Unknown options are passed through unchanged. Known options (other
- * than --debug, which is preserved) and the mountpoint argument are
- * removed from *args*.
- *
- * If --help or --version is specified, the appropriate information is
- * printed to stdout and the function returns -1.
- *
- * If neither -o subtype= or -o fsname= options are given, the subtype
- * is set to the basename of the program (the fsname defaults to
- * "fuse").
+ * using the low-level API. A help text that describes the available
+ * options can be printed with `fuse_cmdline_help`. A single
+ * non-option argument is treated as the mountpoint. Multiple
+ * non-option arguments will result in an error.
+ *
+ * If neither -o subtype= or -o fsname= options are given, a new
+ * subtype option will be added and set to the basename of the program
+ * (the fsname will remain unset, and then defaults to "fuse").
  *
  * @param args argument vector (input+output)
  * @param opts output argument for parsed options
diff --git a/lib/fuse_versionscript b/lib/fuse_versionscript
index 14eb362..3301b12 100644
--- a/lib/fuse_versionscript
+++ b/lib/fuse_versionscript
@@ -127,6 +127,7 @@ FUSE_3.0 {
 		fuse_lowlevel_help;
 		fuse_lowlevel_version;
 		fuse_mount_help;
+		fuse_cmdline_help;
 		fuse_mount_version;
 
 	local:
diff --git a/lib/helper.c b/lib/helper.c
index 140de00..da93413 100644
--- a/lib/helper.c
+++ b/lib/helper.c
@@ -48,12 +48,7 @@ static const struct fuse_opt fuse_helper_opts[] = {
 	FUSE_OPT_END
 };
 
-static void usage(const char *progname)
-{
-	printf("usage: %s mountpoint [options]\n\n", progname);
-}
-
-static void helper_help(void)
+void fuse_cmdline_help(void)
 {
 	printf("General options:\n"
 	       "    -h   --help            print help\n"
@@ -64,11 +59,6 @@ static void helper_help(void)
 	       "\n");
 }
 
-static void helper_version(void)
-{
-	printf("FUSE library version: %s\n", PACKAGE_VERSION);
-}
-
 static int fuse_helper_opt_proc(void *data, const char *arg, int key,
 				struct fuse_args *outargs)
 {
@@ -126,27 +116,6 @@ int fuse_parse_cmdline(struct fuse_args *args,
 			   fuse_helper_opt_proc) == -1)
 		return -1;
 
-	if (opts->show_version) {
-		helper_version();
-		fuse_lowlevel_version();
-		fuse_mount_version();
-		return -1;
-	}
-
-	if (opts->show_help) {
-		usage(args->argv[0]);
-		helper_help();
-		fuse_lowlevel_help();
-		fuse_mount_help();
-		return -1;
-	}
-
-	if (!opts->mountpoint) {
-		fprintf(stderr, "error: no mountpoint specified\n");
-		usage(args->argv[0]);
-		return -1;
-	}
-
 	/* If neither -o subtype nor -o fsname are specified,
 	   set subtype to program's basename */
 	if (!opts->nodefault_subtype)
@@ -225,7 +194,7 @@ int fuse_main_real(int argc, char *argv[], const struct fuse_operations *op,
 		return 1;
 
 	if (opts.show_version) {
-		helper_version();
+		printf("FUSE library version %s\n", PACKAGE_VERSION);
 		fuse_lowlevel_version();
 		fuse_mount_version();
 		res = 0;
@@ -235,7 +204,7 @@ int fuse_main_real(int argc, char *argv[], const struct fuse_operations *op,
 	/* Re-add --help for later processing by fuse_new()
 	   (that way we also get help for modules options) */
 	if (opts.show_help) {
-		helper_help();
+		fuse_cmdline_help();
 		if (fuse_opt_add_arg(&args, "--help") == -1) {
 			res = 1;
 			goto out1;
@@ -245,7 +214,6 @@ int fuse_main_real(int argc, char *argv[], const struct fuse_operations *op,
 	if (!opts.show_help &&
 	    !opts.mountpoint) {
 		fprintf(stderr, "error: no mountpoint specified\n");
-		usage(args.argv[0]);
 		res = 1;
 		goto out1;
 	}