Don't handle --help and --version in fuse_session_new().

Help and version messages can be generated using the new
fuse_lowlevel_help(), fuse_lowlevel_version(), fuse_mount_help(), and
fuse_mount_version() functions.

The fuse_parse_cmdline() function has been made more powerful
to do this automatically, and is now explicitly intended only
for low-level API users.

This is a code simplication patch. We don't have to parse for --help and
--version in quite as many places, and we no longer have a low-level
initialization function be responsible for the (super-high level) task
of printing a program usage message.

In the high-level API, we can now handle the command line parsing
earlier and avoid running other initialization code if we're just going
to abort later on.

2 files changed, 62 insertions, 31 deletions

diff --git a/include/fuse_common.h b/include/fuse_common.h
index f39dab3..f32c872 100644
--- a/include/fuse_common.h
+++ b/include/fuse_common.h
@@ -209,34 +209,6 @@ struct fuse_session;
 struct fuse_pollhandle;
 
 /**
- * Utility functions for simple file systems to parse common options.
- *
- * The following options are parsed:
- *
- *   '-f'	     foreground
- *   '-d' '-odebug'  foreground, but keep the debug option
- *   '-s'	     single threaded
- *   '-h' '--help'   help
- *   '-ho'	     help without header
- *   '-ofsname=..'   file system name, if not present, then set to the program
- *		     name
- *
- * Unknown parameters in `args` are passed through unchanged. Known
- * parameters (with the exception of --help and --version) are removed.
- *
- * All parameters may be NULL (in which case they may still
- * be specified on the command line, but will not be set).
- *
- * @param args argument vector
- * @param mountpoint the returned mountpoint, should be freed after use
- * @param multithreaded set to 1 unless the '-s' option is present
- * @param foreground set to 1 if one of the relevant options is present
- * @return 0 on success, -1 on failure
- */
-int fuse_parse_cmdline(struct fuse_args *args, char **mountpoint,
-		       int *multithreaded, int *foreground);
-
-/**
  * Go into the background
  *
  * @param foreground if true, stay in the foreground
diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h
index f90a052..0822e51 100644
--- a/include/fuse_lowlevel.h
+++ b/include/fuse_lowlevel.h
@@ -1560,10 +1560,72 @@ void fuse_req_interrupt_func(fuse_req_t req, fuse_interrupt_func_t func,
  */
 int fuse_req_interrupted(fuse_req_t req);
 
+
+/* ----------------------------------------------------------- *
+ * Inquiry functions                                           *
+ * ----------------------------------------------------------- */
+
+/**
+ * Print FUSE library version to stdout.
+ */
+void fuse_lowlevel_version(void);
+
+/**
+ * Print FUSE mount (fusermount) version stdout.
+ */
+void fuse_mount_version(void);
+
+/**
+ * Print available low-level options to stdout.
+ * These options may be passed to `fuse_session_new()`
+ */
+void fuse_lowlevel_help(void);
+
+/**
+ * Print available mount options to stdout.
+ * These options may be passed to `fuse_session_new()`
+ */
+void fuse_mount_help(void);
+
 /* ----------------------------------------------------------- *
  * Filesystem setup & teardown                                 *
  * ----------------------------------------------------------- */
 
+struct fuse_cmdline_opts {
+	int singlethread;
+	int foreground;
+	int debug;
+	int nodefault_subtype;
+	char *mountpoint;
+	int show_version;
+	int show_help;
+};
+
+/**
+ * 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 proceeds normally.
+ *
+ * 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").
+ *
+ * @param args argument vector (input+output)
+ * @param opts output argument for parsed options
+ * @return 0 on success, -1 on failure
+ */
+int fuse_parse_cmdline(struct fuse_args *args,
+		       struct fuse_cmdline_opts *opts);
+
 /**
  * Create a low level session.
  *
@@ -1574,9 +1636,6 @@ int fuse_req_interrupted(fuse_req_t req);
  * `struct fuse_opt fuse_mount_opts[]`. If not all options are known,
  * an error message is written to stderr and the function returns NULL.
  *
- * If the --help or --version parameters are specified, the function
- * prints the requsted information to stdout and returns NULL.
- *
  * @param args argument vector
  * @param op the (low-level) filesystem operations
  * @param op_size sizeof(struct fuse_lowlevel_ops)