/* args.c - Command line argument parsing.
*
* Copyright 2006 Rob Landley <rob@landley.net>
*/
// NOTE: If option parsing segfaults, switch on TOYBOX_DEBUG in menuconfig.
// Enabling TOYBOX_DEBUG in .config adds syntax checks to option string parsing
// which aren't needed in the final code (your option string is hardwired and
// should be correct when you ship), but are useful for development.
#include "toys.h"
// Design goals:
// Don't use getopt() out of libc.
// Don't permute original arguments (screwing up ps/top output).
// Integrated --long options "(noshort)a(along)b(blong1)(blong2)"
/* This uses a getopt-like option string, but not getopt() itself. We call
* it the get_opt string.
*
* Each option in the get_opt string corresponds to a bit position in the
* return value. The rightmost argument is (1<<0), the next to last is (1<<1)
* and so on. If the option isn't seen in argv[], its bit remains 0.
*
* Options which have an argument fill in the corresponding slot in the global
* union "this" (see generated/globals.h), which it treats as an array of longs
* (note that sizeof(long)==sizeof(pointer) is guaranteed by LP64).
*
* You don't have to free the option strings, which point into the environment
* space. List objects should be freed by main() when command_main() returns.
*
* Example:
* Calling get_optflags() when toys.which->options="ab:c:d" and
* argv = ["command", "-b", "fruit", "-d", "walrus"] results in:
*
* Changes to struct toys:
* toys.optflags = 5 (I.E. 0101 so -b = 4 | -d = 1)
* toys.optargs[0] = "walrus" (leftover argument)
* toys.optargs[1] = NULL (end of list)
* toys.optc = 1 (there was 1 leftover argument)
*
* Changes to union this:
* this[0]=NULL (because -c didn't get an argument this time)
* this[1]="fruit" (argument to -b)
*/
// What you can put in a get_opt string:
// Any otherwise unused character (all letters, unprefixed numbers) specify
// an option that sets a flag. The bit value is the same as the binary digit
// if you string the option characters together in order.
// So in "abcdefgh" a = 128, h = 1
//
// Suffixes specify that this option takes an argument (stored in GLOBALS):
// Note that pointer and long are always the same size, even on 64 bit.
// : plus a string argument, keep most recent if more than one
// * plus a string argument, appended to a list
// # plus a signed long argument
// <LOW - die if less than LOW
// >HIGH - die if greater than HIGH
// =DEFAULT - value if not specified
// - plus a signed long argument defaulting to negative (say + for positive)
// . plus a double precision floating point argument (with CFG_TOYBOX_FLOAT)
// Chop this option out with USE_TOYBOX_FLOAT() in option string
// Same <LOW>HIGH=DEFAULT as #
// @ plus an occurrence counter (which is a long)
// (longopt)
// | this is required. If more than one marked, only one required.
// ; long option's argument is optional (can only be supplied with --opt=)
// ^ Stop parsing after encountering this argument
// " " (space char) the "plus an argument" must be separate
// I.E. "-j 3" not "-j3". So "kill -stop" != "kill -s top"
//
// At the beginning of the get_opt string (before any options):
// ^ stop at first nonoption argument
// <0 die if less than # leftover arguments (default 0)
// >9 die if > # leftover arguments (default MAX_INT)
// ? Allow unknown arguments (pass them through to command).
// & first argument has imaginary dash (ala tar/ps)
// If given twice, all arguments have imaginary dash
//
// At the end: [groups] of previously seen options
// - Only one in group (switch off) [-abc] means -ab=-b, -ba=-a, -abc=-c
// + Synonyms (switch on all) [+abc] means -ab=-abc, -c=-abc
// ! More than one in group is error [!abc] means -ab calls error_exit()
// primarily useful if you can switch things back off again.
// Notes from getopt man page
// - and -- cannot be arguments.
// -- force end of arguments
// - is a synonym for stdin in file arguments
// -abcd means -a -b -c -d (but if -b takes an argument, then it's -a -b cd)
// Linked list of all known options (option string parsed into this).
// Hangs off getoptflagstate, freed at end of option parsing.
struct opts {
struct opts *next;
long *arg; // Pointer into union "this" to store arguments at.
int c; // Argument character to match
int flags; // |=1, ^=2, " "=4, ;=8
unsigned long long dex[3]; // bits to disable/enable/exclude in toys.optflags
char type; // Type of arguments to store union "this"
union {
long l;
FLOAT f;
} val[3]; // low, high, default - range of allowed values
};
// linked list of long options. (Hangs off getoptflagstate, free at end of
// option parsing, details about flag to set and global slot to fill out
// stored in related short option struct, but if opt->c = -1 the long option
// is "bare" (has no corresponding short option).
struct longopts {
struct longopts *next;
struct opts *opt;
char *str;
int len;
};
// State during argument parsing.
struct getoptflagstate
{
int argc, minargs, maxargs, nodash;
char *arg;
struct opts *opts;
struct longopts *longopts;
int noerror, nodash_now, stopearly;
unsigned excludes, requires;
};
// Use getoptflagstate to parse parse one command line option from argv
static int gotflag(struct getoptflagstate *gof, struct opts *opt)
{
int type;
// Did we recognize this option?
if (!opt) {
if (gof->noerror) return 1;
error_exit("Unknown option %s", gof->arg);
}
// Might enabling this switch off something else?
if (toys.optflags & opt->dex[0]) {
struct opts *clr;
unsigned long long i = 1;
// Forget saved argument for flag we switch back off
for (clr=gof->opts, i=1; clr; clr = clr->next, i<<=1)
if (clr->arg && (i & toys.optflags & opt->dex[0])) *clr->arg = 0;
toys.optflags &= ~opt->dex[0];
}
// Set flags
toys.optflags |= opt->dex[1];
gof->excludes |= opt->dex[2];
if (opt->flags&2) gof->stopearly=2;
if (toys.optflags & gof->excludes) {
struct opts *bad;
unsigned i = 1;
for (bad=gof->opts, i=1; bad ;bad = bad->next, i<<=1) {
if (opt == bad || !(i & toys.optflags)) continue;
if (toys.optflags & bad->dex[2]) break;
}
if (bad) error_exit("No '%c' with '%c'", opt->c, bad->c);
}
// Does this option take an argument?
if (!gof->arg) {
if (opt->flags & 8) return 0;
gof->arg = "";
} else gof->arg++;
type = opt->type;
if (type == '@') ++*(opt->arg);
else if (type) {
char *arg = gof->arg;
// Handle "-xblah" and "-x blah", but also a third case: "abxc blah"
// to make "tar xCjfv blah1 blah2 thingy" work like
// "tar -x -C blah1 -j -f blah2 -v thingy"
if (gof->nodash_now || (!arg[0] && !(opt->flags & 8)))
arg = toys.argv[++gof->argc];
if (!arg) {
char *s = "Missing argument to ";
struct longopts *lo;
if (opt->c != -1) error_exit("%s-%c", s, opt->c);
for (lo = gof->longopts; lo->opt != opt; lo = lo->next);
error_exit("%s--%.*s", s, lo->len, lo->str);
}
if (type == ':') *(opt->arg) = (long)arg;
else if (type == '*') {
struct arg_list **list;
list = (struct arg_list **)opt->arg;
while (*list) list=&((*list)->next);
*list = xzalloc(sizeof(struct arg_list));
(*list)->arg = arg;
} else if (type == '#' || type == '-') {
long l = atolx(arg);
if (type == '-' && !ispunct(*arg)) l*=-1;
if (l < opt->val[0].l) error_exit("-%c < %ld", opt->c, opt->val[0].l);
if (l > opt->val[1].l) error_exit("-%c > %ld", opt->c, opt->val[1].l);
*(opt->arg) = l;
} else if (CFG_TOYBOX_FLOAT && type == '.') {
FLOAT *f = (FLOAT *)(opt->arg);
*f = strtod(arg, &arg);
if (opt->val[0].l != LONG_MIN && *f < opt->val[0].f)
error_exit("-%c < %lf", opt->c, (double)opt->val[0].f);
if (opt->val[1].l != LONG_MAX && *f > opt->val[1].f)
error_exit("-%c > %lf", opt->c, (double)opt->val[1].f);
}
if (!gof->nodash_now) gof->arg = "";
}
return 0;
}
// Parse this command's options string into struct getoptflagstate, which
// includes a struct opts linked list in reverse order (I.E. right-to-left)
void parse_optflaglist(struct getoptflagstate *gof)
{
char *options = toys.which->options;
long *nextarg = (long *)&this;
struct opts *new = 0;
int idx;
// Parse option format string
memset(gof, 0, sizeof(struct getoptflagstate));
gof->maxargs = INT_MAX;
if (!options) return;
// Parse leading special behavior indicators
for (;;) {
if (*options == '^') gof->stopearly++;
else if (*options == '<') gof->minargs=*(++options)-'0';
else if (*options == '>') gof->maxargs=*(++options)-'0';
else if (*options == '?') gof->noerror++;
else if (*options == '&') gof->nodash++;
else break;
options++;
}
// Parse option string into a linked list of options with attributes.
if (!*options) gof->stopearly++;
while (*options) {
char *temp;
// Option groups come after all options are defined
if (*options == '[') break;
// Allocate a new list entry when necessary
if (!new) {
new = xzalloc(sizeof(struct opts));
new->next = gof->opts;
gof->opts = new;
new->val[0].l = LONG_MIN;
new->val[1].l = LONG_MAX;
}
// Each option must start with "(" or an option character. (Bare
// longopts only come at the start of the string.)
if (*options == '(' && new->c != -1) {
char *end;
struct longopts *lo;
// Find the end of the longopt
for (end = ++options; *end && *end != ')'; end++);
if (CFG_TOYBOX_DEBUG && !*end) error_exit("(longopt) didn't end");
// init a new struct longopts
lo = xmalloc(sizeof(struct longopts));
lo->next = gof->longopts;
lo->opt = new;
lo->str = options;
lo->len = end-options;
gof->longopts = lo;
options = ++end;
// Mark this struct opt as used, even when no short opt.
if (!new->c) new->c = -1;
continue;
// If this is the start of a new option that wasn't a longopt,
} else if (strchr(":*#@.-", *options)) {
if (CFG_TOYBOX_DEBUG && new->type)
error_exit("multiple types %c:%c%c", new->c, new->type, *options);
new->type = *options;
} else if (-1 != (idx = stridx("|^ ;", *options))) new->flags |= 1<<idx;
// bounds checking
else if (-1 != (idx = stridx("<>=", *options))) {
if (new->type == '#') {
long l = strtol(++options, &temp, 10);
if (temp != options) new->val[idx].l = l;
} else if (CFG_TOYBOX_FLOAT && new->type == '.') {
FLOAT f = strtod(++options, &temp);
if (temp != options) new->val[idx].f = f;
} else if (CFG_TOYBOX_DEBUG) error_exit("<>= only after .#");
options = --temp;
// At this point, we've hit the end of the previous option. The
// current character is the start of a new option. If we've already
// assigned an option to this struct, loop to allocate a new one.
// (It'll get back here afterwards and fall through to next else.)
} else if (new->c) {
new = 0;
continue;
// Claim this option, loop to see what's after it.
} else new->c = *options;
options++;
}
// Initialize enable/disable/exclude masks and pointers to store arguments.
// (This goes right to left so we need the whole list before we can start.)
idx = 0;
for (new = gof->opts; new; new = new->next) {
unsigned long long u = 1L<<idx++;
if (new->c == 1) new->c = 0;
new->dex[1] = u;
if (new->flags & 1) gof->requires |= u;
if (new->type) {
new->arg = (void *)nextarg;
*(nextarg++) = new->val[2].l;
}
}
// Parse trailing group indicators
while (*options) {
unsigned bits = 0;
if (CFG_TOYBOX_DEBUG && *options != '[') error_exit("trailing %s", options);
idx = stridx("-+!", *++options);
if (CFG_TOYBOX_DEBUG && idx == -1) error_exit("[ needs +-!");
if (CFG_TOYBOX_DEBUG && (options[1] == ']' || !options[1]))
error_exit("empty []");
// Don't advance past ] but do process it once in loop.
while (*options++ != ']') {
struct opts *opt;
int i;
if (CFG_TOYBOX_DEBUG && !*options) error_exit("[ without ]");
// Find this option flag (in previously parsed struct opt)
for (i=0, opt = gof->opts; ; i++, opt = opt->next) {
if (*options == ']') {
if (!opt) break;
if (bits&(1<<i)) opt->dex[idx] |= bits&~(1<<i);
} else {
if (*options==1) break;
if (CFG_TOYBOX_DEBUG && !opt)
error_exit("[] unknown target %c", *options);
if (opt->c == *options) {
bits |= 1<<i;
break;
}
}
}
}
}
}
// Fill out toys.optflags, toys.optargs, and this[] from toys.argv
void get_optflags(void)
{
struct getoptflagstate gof;
struct opts *catch;
unsigned long long saveflags;
char *letters[]={"s",""};
// Option parsing is a two stage process: parse the option string into
// a struct opts list, then use that list to process argv[];
// Allocate memory for optargs
saveflags = 0;
while (toys.argv[saveflags++]);
toys.optargs = xzalloc(sizeof(char *)*saveflags);
parse_optflaglist(&gof);
// Iterate through command line arguments, skipping argv[0]
for (gof.argc=1; toys.argv[gof.argc]; gof.argc++) {
gof.arg = toys.argv[gof.argc];
catch = NULL;
// Parse this argument
if (gof.stopearly>1) goto notflag;
gof.nodash_now = 0;
// Various things with dashes
if (*gof.arg == '-') {
// Handle -
if (!gof.arg[1]) goto notflag;
gof.arg++;
if (*gof.arg=='-') {
struct longopts *lo;
gof.arg++;
// Handle --
if (!*gof.arg) {
gof.stopearly += 2;
continue;
}
// do we match a known --longopt?
for (lo = gof.longopts; lo; lo = lo->next) {
if (!strncmp(gof.arg, lo->str, lo->len)) {
if (!gof.arg[lo->len]) gof.arg = 0;
else if (gof.arg[lo->len] == '=' && lo->opt->type)
gof.arg += lo->len;
else continue;
// It's a match.
catch = lo->opt;
break;
}
}
// Should we handle this --longopt as a non-option argument?
if (!lo && gof.noerror) {
gof.arg -= 2;
goto notflag;
}
// Long option parsed, handle option.
gotflag(&gof, catch);
continue;
}
// Handle things that don't start with a dash.
} else {
if (gof.nodash && (gof.nodash>1 || gof.argc == 1)) gof.nodash_now = 1;
else goto notflag;
}
// At this point, we have the args part of -args. Loop through
// each entry (could be -abc meaning -a -b -c)
saveflags = toys.optflags;
while (*gof.arg) {
// Identify next option char.
for (catch = gof.opts; catch; catch = catch->next)
if (*gof.arg == catch->c)
if (!((catch->flags&4) && gof.arg[1])) break;
// Handle option char (advancing past what was used)
if (gotflag(&gof, catch) ) {
toys.optflags = saveflags;
gof.arg = toys.argv[gof.argc];
goto notflag;
}
}
continue;
// Not a flag, save value in toys.optargs[]
notflag:
if (gof.stopearly) gof.stopearly++;
toys.optargs[toys.optc++] = toys.argv[gof.argc];
}
// Sanity check
if (toys.optc<gof.minargs)
error_exit("Need%s %d argument%s", letters[!!(gof.minargs-1)],
gof.minargs, letters[!(gof.minargs-1)]);
if (toys.optc>gof.maxargs)
error_exit("Max %d argument%s", gof.maxargs, letters[!(gof.maxargs-1)]);
if (gof.requires && !(gof.requires & toys.optflags)) {
struct opts *req;
char needs[32], *s = needs;
for (req = gof.opts; req; req = req->next)
if (req->flags & 1) *(s++) = req->c;
*s = 0;
error_exit("Needs %s-%s", s[1] ? "one of " : "", needs);
}
if (CFG_TOYBOX_FREE) {
llist_traverse(gof.opts, free);
llist_traverse(gof.longopts, free);
}
}