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authorRob Landley <rob@landley.net>2006-11-19 02:49:22 -0500
committerRob Landley <rob@landley.net>2006-11-19 02:49:22 -0500
commit8324b89598b2aee0957a0378f0f63ff5755498be (patch)
tree6958c34834147ab29607a8e67aca2b05a751f2ee /lib/args.c
parentb29ceb8bd0f99134fe215eebc531dbcd7717e8ae (diff)
downloadtoybox-8324b89598b2aee0957a0378f0f63ff5755498be.tar.gz
New option parsing infrastructure (doesn't use getopt). Hook it up to
existing applets. Still a bit buggy, but bits of it work.
Diffstat (limited to 'lib/args.c')
-rw-r--r--lib/args.c284
1 files changed, 284 insertions, 0 deletions
diff --git a/lib/args.c b/lib/args.c
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+/* 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
+// ? return array of remaining arguments in first vararg
+// <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 use the next vararg. (So varargs used by options go from left to
+ * right, but bits set by arguments go from right to left.)
+ *
+ * Example:
+ * get_optflags("ab:c:d", NULL, &bstring, &cstring);
+ * argv = ["command", "-b", "fruit", "-d"]
+ * flags = 5, bstring="fruit", cstring=NULL;
+ */
+
+struct opts {
+ struct opts *next;
+ char c;
+ int type;
+ int shift;
+ void *arg;
+};
+
+struct getoptflagstate
+{
+ int argc;
+ char *arg;
+ struct opts *opts, *this;
+ int noerror, nodash_now;
+};
+
+static struct getoptflagstate gof;
+
+// Returns zero if it didn't consume the rest of the current -abcdef
+static int gotflag(void)
+{
+ char *arg = NULL;
+ int type;
+ int ret = 0;
+
+ // Did we recognize this option?
+ if (!gof.this && !gof.noerror) error_exit("Unknown option %s\n", gof.arg);
+ else toys.optflags |= 1 << gof.this->shift;
+
+ // Does this option take an argument?
+ gof.arg++;
+ if (gof.this->type & 255) {
+ // 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");
+ } else {
+ arg = gof.arg;
+ ret++;
+ }
+ } else gof.this = NULL;
+
+ // If the last option had an argument, grab it.
+ if (!gof.this) return 0;
+ type = gof.this->type & 255;
+ if (!gof.arg && !(gof.arg = toys.argv[++gof.argc]))
+ error_exit("Missing argument");
+ if (type == ':') gof.this->arg = arg;
+ else if (type == '*') {
+ struct arg_list *temp, **list;
+ list = (struct arg_list **)gof.this->arg;
+ temp = xmalloc(sizeof(struct arg_list));
+ temp->arg = arg;
+ temp->next = *list;
+ *list = temp;
+ } else if (type == '?') {
+ } else if (type == '@') {
+ }
+
+ return ret;
+}
+
+// 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 = INT_MAX;
+ struct longopts {
+ struct longopts *next;
+ struct opts *opt;
+ char *str;
+ int len;
+ } *longopts = NULL;
+ long *nextarg = (long *)&toy;
+ char *options = toys.which->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_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;
+ // Pointer and long guaranteed to be the same size by LP64.
+ *(++nextarg) = 0;
+ gof.this->arg = (void *)nextarg;
+ } 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 (have to calculate this ahead of time because
+ // longopts jump into the middle of the list), and allocate space to
+ // store optargs.
+ gof.argc = 0;
+ for (gof.this = gof.opts; gof.this; gof.this = gof.this->next)
+ gof.this->shift = gof.argc++;
+ toys.optargs = xzalloc(sizeof(char *)*(++gof.argc));
+
+ // Iterate through command line arguments, skipping argv[0]
+ for (gof.argc=1; toys.argv[gof.argc]; gof.argc++) {
+ char *arg = toys.argv[gof.argc];
+
+ // Parse this argument
+ if (stopearly>1) goto notflag;
+
+ gof.nodash_now = 0;
+
+ // Various things with dashes
+ if (*arg == '-') {
+
+ // Handle -
+ if (!arg[1]) goto notflag;
+ arg++;
+ if (*arg=='-') {
+ struct longopts *lo;
+
+ arg++;
+ // Handle --
+ if (!*arg) {
+ stopearly += 2;
+ goto notflag;
+ }
+ // Handle --longopt
+
+ for (lo = longopts; lo; lo = lo->next) {
+ if (!strncmp(arg, lo->str, lo->len)) {
+ if (arg[lo->len]) {
+ if (arg[lo->len]=='='
+ && (lo->opt->type & 255))
+ {
+ arg += lo->len;
+ } else continue;
+
+ // *options should be nul, this makes sure
+ // that the while (*arg) loop terminates;
+ } arg = options-1;
+ gof.this = lo->opt;
+ break;
+ }
+ }
+ // Long option parsed, jump to option handling.
+ 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 (*arg) {
+ // Identify next option char.
+ for (gof.this = gof.opts; gof.this && *arg != gof.this->c;
+ gof.this = gof.this->next);
+ if (gotflag()) break;
+ arg++;
+ }
+ 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 arguments", minargs);
+ if (optarg>maxargs) error_exit("Max %d arguments", maxargs);
+}