/* vi: set sw=4 ts=4 : * args.c - Command line argument parsing. * * Copyright 2006 Rob Landley <rob@landley.net> */ #include "toys.h" // Design goals: // Don't use getopt() // Don't permute original arguments. // handle --long gracefully "(noshort)a(along)b(blong1)(blong2)" // After each argument: // 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 (TODO: Bounds checking?) // @ plus an occurrence counter (which is a long) // | this is required. If more than one marked, only one required. // (longopt) // +X enabling this enables X (switch on) // ~X enabling this disables X (switch off) // x~x means toggle x, I.E. specifying it again switches it off. // !X die with error if X already set (x!x die if x supplied twice) // [yz] needs at least one of y or z. // at the beginning: // + stop at first nonoption argument // <0 at least # leftover arguments needed (default 0) // >9 at most # leftover arguments needed (default MAX_INT) // ? don't show_usage() on unknown argument. // & first argument has imaginary dash (ala tar/ps) // If given twice, all arguments have imaginary dash // Notes from getopt man page // - and -- cannot be arguments. // -- force end of arguments // - is a synonym for stdin in file arguments // -abc means -a -b -c /* This uses a getopt-like option string, but not getopt() itself. * * Each option in options corresponds to a bit position in the return * value (last argument is (1<<0), the next to last is (1<<1) and so on). * If the option isn't seen in argv[] its bit is 0. * * Options which have an argument fill in the corresponding slot in the global * toys.command struct, 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 list objects should be freed by main() when command_main() * returns. * * Example: * get_optflags() when toys.which->options="ab:c:d" * argv = ["command", "-b", "fruit", "-d"] * flags = 5, toy[0]=NULL, toy[1]="fruit"; */ // struct opts { struct opts *next; char c; int type; int shift; long *arg; }; struct getoptflagstate { int argc; char *arg; struct opts *opts, *this; int noerror, nodash_now; }; static struct getoptflagstate gof; static void gotflag(void) { int type; // Did we recognize this option? if (!gof.this && !gof.noerror) error_exit("Unknown option %s", gof.arg); else toys.optflags |= 1 << gof.this->shift; // Does this option take an argument? gof.arg++; type = gof.this->type & 255; if (type) { // 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 && !*gof.arg) { gof.arg = toys.argv[++gof.argc]; if (!gof.arg) error_exit("Missing argument"); } // Grab argument. if (!gof.arg && !(gof.arg = toys.argv[++gof.argc])) error_exit("Missing argument"); if (type == ':') *(gof.this->arg) = (long)gof.arg; else if (type == '*') { struct arg_list *temp, **list; list = (struct arg_list **)gof.this->arg; temp = xmalloc(sizeof(struct arg_list)); temp->arg = gof.arg; temp->next = *list; *list = temp; } else if (type == '#') *(gof.this->arg) = atolx((char *)gof.arg); else if (type == '@') { } gof.arg = ""; } gof.this = NULL; } // Fill out toys.optflags and toys.optargs. This isn't reentrant because // we don't bzero(&gof, sizeof(gof)); void get_optflags(void) { int stopearly = 0, optarg = 0, nodash = 0, minargs = 0, maxargs; struct longopts { struct longopts *next; struct opts *opt; char *str; int len; } *longopts = NULL; long *nextarg = (long *)&toy; char *options = toys.which->options; if (CFG_HELP) toys.exithelp++; // Allocate memory for optargs maxargs = 0; while (toys.argv[maxargs++]); toys.optargs = xzalloc(sizeof(char *)*maxargs); maxargs = INT_MAX; // Parse option format if (options) { // Parse leading special behavior indicators for (;;) { if (*options == '+') stopearly++; else if (*options == '<') minargs=*(++options)-'0'; else if (*options == '>') maxargs=*(++options)-'0'; else if (*options == '?') gof.noerror++; else if (*options == '&') nodash++; else break; options++; } // Parse rest of opts into array while (*options) { // Allocate a new option entry when necessary if (!gof.this) { gof.this = xzalloc(sizeof(struct opts)); gof.this->next = gof.opts; gof.opts = gof.this; } // Each option must start with (or an option character. (Bare // longopts only come at the start of the string.) if (*options == '(') { char *end; struct longopts *lo = xmalloc(sizeof(struct longopts)); // Find the end of the longopt for (end = ++options; *end && *end != ')'; end++); if (CFG_TOYBOX_DEBUG && !*end) error_exit("Unterminated optstring"); // Allocate and init a new struct longopts lo = xmalloc(sizeof(struct longopts)); lo->next = longopts; lo->opt = gof.this; lo->str = options; lo->len = end-options; longopts = lo; options = end; // For leading longopts (with no corresponding short opt), note // that this option struct has been used. gof.this->shift++; // If this is the start of a new option that wasn't a longopt, } else if (index(":*#@", *options)) { gof.this->type |= *options; } else if (*options == '|') { } else if (*options == '+') { } else if (*options == '~') { } else if (*options == '!') { } else if (*options == '[') { // 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.) } else if(gof.this->shift || gof.this->c) { gof.this = NULL; continue; // Claim this option, loop to see what's after it. } else gof.this->c = *options; options++; } } // Initialize shift bits and pointers to store arguments. (We have to // calculate this ahead of time because longopts jump into the middle of // the list.) gof.argc = 0; for (gof.this = gof.opts; gof.this; gof.this = gof.this->next) { gof.this->shift = gof.argc++; if (gof.this->type & 255) { gof.this->arg = (void *)nextarg; *(nextarg++) = 0; } } // Iterate through command line arguments, skipping argv[0] for (gof.argc=1; toys.argv[gof.argc]; gof.argc++) { gof.arg = toys.argv[gof.argc]; gof.this = NULL; // Parse this argument if (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) { stopearly += 2; goto notflag; } // Handle --longopt for (lo = longopts; lo; lo = lo->next) { if (!strncmp(gof.arg, lo->str, lo->len)) { if (gof.arg[lo->len]) { if (gof.arg[lo->len]=='=' && (lo->opt->type & 255)) { gof.arg += lo->len; } else continue; } // It's a match. gof.arg = ""; gof.this = lo->opt; break; } } // Long option parsed, handle option. gotflag(); continue; } // Handle things that don't start with a dash. } else { if (nodash && (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) while (*gof.arg) { // Identify next option char. for (gof.this = gof.opts; gof.this; gof.this = gof.this->next) if (*gof.arg == gof.this->c) break; // Handle option char (advancing past what was used) gotflag(); } continue; // Not a flag, save value in toys.optargs[] notflag: if (stopearly) stopearly++; toys.optargs[optarg++] = toys.argv[gof.argc]; } // Sanity check if (optarg<minargs) error_exit("Need %d argument%s", minargs, minargs ? "s" : ""); if (optarg>maxargs) error_exit("Max %d argument%s", maxargs, maxargs ? "s" : ""); if (CFG_HELP) toys.exithelp = 0; } // Loop through files listed on the command line static int dofileargs(char ***files, int fd, int iswrite) { char *filename = *((*files)++); static int flags[] = {O_RDONLY, O_CREAT|O_TRUNC, O_RDWR}; if (fd != -1) close(fd); for (;;) { // Are there no more files? if (!*filename) return (fd == -1) ? iswrite : -1; // A filename of "-" means stdin. if (*filename == '-' && !filename[1]) return 0; fd = xcreate(filename, flags[iswrite], 0777); } } int readfileargs(char ***files, int fd) { return dofileargs(files, fd, 0); } int writefileargs(char ***files, int fd) { return dofileargs(files, fd, 1); }