/* 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 unsigned dex[3]; // which 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; help_exit("Unknown option %s", gof->arg); } // Might enabling this switch off something else? if (toys.optflags & opt->dex[0]) { struct opts *clr; unsigned 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->next, i<<=1) { if (opt == bad || !(i & toys.optflags)) continue; if (toys.optflags & bad->dex[2]) break; } help_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) help_exit("%s-%c", s, opt->c); for (lo = gof->longopts; lo->opt != opt; lo = lo->next); help_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) help_exit("-%c < %ld", opt->c, opt->val[0].l); if (l > opt->val[1].l) help_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) help_exit("-%c < %lf", opt->c, (double)opt->val[0].f); if (opt->val[1].l != LONG_MAX && *f > opt->val[1].f) help_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 u = 1<<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 (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; 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) help_exit("Need%s %d argument%s", letters[!!(gof.minargs-1)], gof.minargs, letters[!(gof.minargs-1)]); if (toys.optc>gof.maxargs) help_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; help_exit("Needs %s-%s", s[1] ? "one of " : "", needs); } if (CFG_TOYBOX_FREE) { llist_traverse(gof.opts, free); llist_traverse(gof.longopts, free); } }