Copyright (c) Ray Lai <ray@raylai.com>
Copyright (c) Helg Bredow <helg@openbsd.org>
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.Dd $Mdocdate: July 8 2018 $ .Dt FUSE_OPT 3 .Os .Sh NAME .Nm FUSE_ARGS_INIT , .Nm FUSE_OPT_IS_OPT_KEY , .Nm FUSE_OPT_KEY , .Nm fuse_opt_add_arg , .Nm fuse_opt_insert_arg , .Nm fuse_opt_add_opt , .Nm fuse_opt_add_opt_escaped , .Nm fuse_opt_free_args , .Nm fuse_opt_match , .Nm fuse_opt_parse .Nd FUSE argument and option parser .Sh SYNOPSIS n fuse_opt.h .Ft struct fuse_args .Fo FUSE_ARGS_INIT .Fa "int argc" .Fa "char argv**" .Fc .Ft int .Fo FUSE_OPT_IS_OPT_KEY .Fa "fuse_opt *t" .Fc .Ft struct fuse_opt .Fo FUSE_OPT_KEY .Fa "const char *templ" .Fa "int key" .Fc .Ft int .Fo fuse_opt_add_arg .Fa "struct fuse_args *args" .Fa "const char *arg" .Fc .Ft int .Fo fuse_opt_insert_arg .Fa "struct fuse_args *args" .Fa "int pos" .Fa "const char *opt" .Fc .Ft int .Fo fuse_opt_add_opt .Fa "char **opts" .Fa "const char *opt" .Fc .Ft int .Fo fuse_opt_add_opt_escaped .Fa "char **opts" .Fa "const char *opt" .Fc .Ft void .Fo fuse_opt_free_args .Fa "struct fuse_args *args" .Fc .Ft int .Fo fuse_opt_match .Fa "const struct fuse_opt *opts" .Fa "const char *opt" .Fc .Ft int .Fo fuse_opt_parse .Fa "struct fuse_args *args" .Fa "void *data" .Fa "const struct fuse_opt *opts" .Fa "fuse_opt_proc_t proc" .Fc .Sh DESCRIPTION These FUSE library functions and macros provide support for complex argument and option parsing. These are typically entered on the command line but may also be passed by file systems to the .Xr fuse_mount 3 and .Xr fuse_new 3 functions. .Ft struct fuse_args holds string options in an array: d -literal -offset indent struct fuse_args { int argc; /* argument count */ char **argv; /* NULL-terminated array of arguments */ int allocated; /* argv was allocated and must be freed */ }; .Ed
p l -tag -width Ds -compact t Fn FUSE_OPT_KEY templ key returns a .Fa struct fuse_opt template that matches an argument or option .Fa templ with option key .Fa key . This macro is used as an element in .Fa struct fuse_opt arrays to create a template that is processed by a fuse_opt_proc_t. The special constants FUSE_OPT_KEEP and FUSE_OPT_DISCARD can be specified if proc does not need to handle this option or argument; proc is not called in this case.
p t Fn FUSE_OPT_IS_OPT_KEY templ checks if .Fa templ is an option key.
p The last element of the .Fa opts .Ft struct fuse_opt option array must be .Dv FUSE_OPT_END .
p .Fa proc points to a function with the following signature: .Ft int (*fuse_opt_proc_t) .Fo proc .Fa "void *data" .Fa "const char *arg" .Fa "int key" .Fa "struct fuse_args *outargs" .Fc
p Special key values: d -literal -offset indent FUSE_OPT_KEY_OPT /* no match */ FUSE_OPT_KEY_NONOPT /* non-option */ FUSE_OPT_KEY_KEEP /* don't process; return 1 */ FUSE_OPT_KEY_DISCARD /* don't process; return 0 */ .Ed
p t Fn FUSE_ARGS_INIT initializes a .Ft struct fuse_args with .Fa argc and .Fa argv , which are usually obtained from .Fn main . .Fa argv is NULL-terminated, and is suitable for use with .Xr execvp 3 . .Fa argv is used directly and .Fa allocated is set to 0.
p t Fn fuse_opt_add_arg adds a single option to the end of .Fa args . If .Fa args->allocated is 0, .Fa args->argv is copied to the heap and .Fa args->allocated is set to a non-zero value.
p t Fn fuse_opt_insert_arg inserts a single argument at position .Fa pos into .Fa args , shifting .Fa args->argv as needed.
p t Fn fuse_opt_add_opt adds an option .Fa opt to a comma-separated string of options .Fa opts . .Fa *opts can be NULL, which is typically used when adding the first option.
p t Fn fuse_opt_add_opt_escaped escapes any .Sq "," and .Sq "\\" characters in .Fa opt before adding it to .Fa opts .
p t Fn fuse_opt_free_args frees .Fa args->argv if it was allocated .Fa args and initializes everything to 0.
p t Fn fuse_opt_match tests if the argument or option .Fa opt appears in the list of templates .Fa opts . If .Fa opt is an option then it must not include the -o prefix.
p t Fn fuse_opt_parse parses options, setting any members of .Fa data automatically depending on the format of the template. If .Fa proc is not NULL, then this is called for any argument that matches a template that has .Fa val = FUSE_OPT_KEY. .Fa opts is an array of .Ft struct fuse_opt , each of which describes actions for each option: d -literal -offset indent struct fuse_opt { const char *templ; /* template for option */ unsigned long off; /* data offset */ int val; /* key value */ }; .Ed
p The following templates are supported. foo=
p foo=%u %u can be any format that can be parsed by .Fn sscanf 3 . If this is %s then a copy of the string is allocated. foo=bar matches the option exactly (treated the same as if it didn't have an =).
p foo matches exactly
p -b or --bar matches the argument "-b " or "--bar " (trailing space) argument expects a value, that is passed to .Fa proc
p -b %u or:w --bar %u Treated the same as foo=%u above
p Each argument or option is matched against every template. This allows more than one member of .Fa data to be set by a single argument or option (see example for gid below). .El .Sh RETURN VALUES .Fn fuse_opt_add_arg , .Fn fuse_opt_insert_arg , .Fn fuse_opt_add_opt , .Fn fuse_opt_add_opt_escaped , and .Fn fuse_opt_parse return 0 on success, -1 on error.
p .Fn fuse_opt_match returns 1 on match, 0 if no match. .Sh ERRORS .Fn fuse_opt_add_arg , .Fn fuse_opt_insert_arg , .Fn fuse_opt_add_opt , and .Fn fuse_opt_add_opt_escaped can run out of memory and set .Va errno . .Sh SEE ALSO .Xr fuse_main 3 .Sh STANDARDS These library functions conform to FUSE 2.6. .Sh HISTORY These functions first appeared in .Ox 5.4 . .Sh AUTHORS .An Sylvestre Gallon Aq Mt ccna.syl@gmail.com .An Helg Bredow Aq Mt xx404@msn.com
p This manual was written by .An Ray Lai Aq Mt ray@raylai.com and updated by .An Helg Bredow Aq Mt xx404@msn.com