text: /*-
   * Copyright (c) 2003-2008 Tim Kientzle
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  /*
   * Command line parser for tar.
   */
  
  #include "bsdtar_platform.h"
  __FBSDID("$FreeBSD$");
  
  #ifdef HAVE_ERRNO_H
  #include <errno.h>
  #endif
  #ifdef HAVE_STDLIB_H
  #include <stdlib.h>
  #endif
  #ifdef HAVE_STRING_H
  #include <string.h>
  #endif
  
  #include "bsdtar.h"
  #include "err.h"
  
  /*
   * Short options for tar.  Please keep this sorted.
   */
  static const char *short_options
  	= "aBb:C:cf:HhI:JjkLlmnOoPpqrSs:T:tUuvW:wX:xyZz";
  
  /*
   * Long options for tar.  Please keep this list sorted.
   *
   * The symbolic names for options that lack a short equivalent are
   * defined in bsdtar.h.  Also note that so far I've found no need
   * to support optional arguments to long options.  That would be
   * a small change to the code below.
   */
  
  static const struct bsdtar_option {
  	const char *name;
  	int required;      /* 1 if this option requires an argument. */
  	int equivalent;    /* Equivalent short option. */
  } tar_longopts[] = {
  	{ "absolute-paths",       0, 'P' },
  	{ "append",               0, 'r' },
  	{ "acls",                 0, OPTION_ACLS },
  	{ "auto-compress",        0, 'a' },
  	{ "b64encode",            0, OPTION_B64ENCODE },
  	{ "block-size",           1, 'b' },
  	{ "blocking-factor",	  1, 'b' },
  	{ "bunzip2",              0, 'j' },
  	{ "bzip",                 0, 'j' },
  	{ "bzip2",                0, 'j' },
  	{ "cd",                   1, 'C' },
  	{ "check-links",          0, OPTION_CHECK_LINKS },
  	{ "chroot",               0, OPTION_CHROOT },
  	{ "clear-nochange-fflags", 0, OPTION_CLEAR_NOCHANGE_FFLAGS },
  	{ "compress",             0, 'Z' },
  	{ "confirmation",         0, 'w' },
  	{ "create",               0, 'c' },
  	{ "dereference",	  0, 'L' },
  	{ "directory",            1, 'C' },
  	{ "disable-copyfile",	  0, OPTION_NO_MAC_METADATA },
  	{ "exclude",              1, OPTION_EXCLUDE },
  	{ "exclude-from",         1, 'X' },
  	{ "extract",              0, 'x' },
  	{ "fast-read",            0, 'q' },
  	{ "fflags",               0, OPTION_FFLAGS },
  	{ "file",                 1, 'f' },
  	{ "files-from",           1, 'T' },
  	{ "format",               1, OPTION_FORMAT },
  	{ "gid",		  1, OPTION_GID },
  	{ "gname",		  1, OPTION_GNAME },
  	{ "grzip",                0, OPTION_GRZIP },
  	{ "gunzip",               0, 'z' },
  	{ "gzip",                 0, 'z' },
  	{ "help",                 0, OPTION_HELP },
  	{ "hfsCompression",       0, OPTION_HFS_COMPRESSION },
  	{ "ignore-zeros",         0, OPTION_IGNORE_ZEROS },
  	{ "include",              1, OPTION_INCLUDE },
  	{ "insecure",             0, 'P' },
  	{ "interactive",          0, 'w' },
  	{ "keep-newer-files",     0, OPTION_KEEP_NEWER_FILES },
  	{ "keep-old-files",       0, 'k' },
  	{ "list",                 0, 't' },
  	{ "lrzip",                0, OPTION_LRZIP },
  	{ "lz4",                  0, OPTION_LZ4 },
  	{ "lzip",                 0, OPTION_LZIP },
  	{ "lzma",                 0, OPTION_LZMA },
  	{ "lzop",                 0, OPTION_LZOP },
  	{ "mac-metadata",         0, OPTION_MAC_METADATA },
  	{ "modification-time",    0, 'm' },
  	{ "newer",		  1, OPTION_NEWER_CTIME },
  	{ "newer-ctime",	  1, OPTION_NEWER_CTIME },
  	{ "newer-ctime-than",	  1, OPTION_NEWER_CTIME_THAN },
  	{ "newer-mtime",	  1, OPTION_NEWER_MTIME },
  	{ "newer-mtime-than",	  1, OPTION_NEWER_MTIME_THAN },
  	{ "newer-than",		  1, OPTION_NEWER_CTIME_THAN },
  	{ "no-acls",              0, OPTION_NO_ACLS },
  	{ "no-fflags",            0, OPTION_NO_FFLAGS },
  	{ "no-mac-metadata",      0, OPTION_NO_MAC_METADATA },
  	{ "no-recursion",         0, 'n' },
  	{ "no-same-owner",	  0, OPTION_NO_SAME_OWNER },
  	{ "no-same-permissions",  0, OPTION_NO_SAME_PERMISSIONS },
  	{ "no-xattr",             0, OPTION_NO_XATTRS },
  	{ "no-xattrs",            0, OPTION_NO_XATTRS },
  	{ "nodump",               0, OPTION_NODUMP },
  	{ "nopreserveHFSCompression",0, OPTION_NOPRESERVE_HFS_COMPRESSION },
  	{ "norecurse",            0, 'n' },
  	{ "null",		  0, OPTION_NULL },
  	{ "numeric-owner",	  0, OPTION_NUMERIC_OWNER },
  	{ "older",		  1, OPTION_OLDER_CTIME },
  	{ "older-ctime",	  1, OPTION_OLDER_CTIME },
  	{ "older-ctime-than",	  1, OPTION_OLDER_CTIME_THAN },
  	{ "older-mtime",	  1, OPTION_OLDER_MTIME },
  	{ "older-mtime-than",	  1, OPTION_OLDER_MTIME_THAN },
  	{ "older-than",		  1, OPTION_OLDER_CTIME_THAN },
  	{ "one-file-system",	  0, OPTION_ONE_FILE_SYSTEM },
  	{ "options",              1, OPTION_OPTIONS },
  	{ "passphrase",		  1, OPTION_PASSPHRASE },
  	{ "posix",		  0, OPTION_POSIX },
  	{ "preserve-permissions", 0, 'p' },
  	{ "read-full-blocks",	  0, 'B' },
  	{ "same-owner",	          0, OPTION_SAME_OWNER },
  	{ "same-permissions",     0, 'p' },
  	{ "strip-components",	  1, OPTION_STRIP_COMPONENTS },
  	{ "to-stdout",            0, 'O' },
  	{ "totals",		  0, OPTION_TOTALS },
  	{ "uid",		  1, OPTION_UID },
  	{ "uname",		  1, OPTION_UNAME },
  	{ "uncompress",           0, 'Z' },
  	{ "unlink",		  0, 'U' },
  	{ "unlink-first",	  0, 'U' },
  	{ "update",               0, 'u' },
  	{ "use-compress-program", 1, OPTION_USE_COMPRESS_PROGRAM },
  	{ "uuencode",             0, OPTION_UUENCODE },
  	{ "verbose",              0, 'v' },
  	{ "version",              0, OPTION_VERSION },
  	{ "xattrs",               0, OPTION_XATTRS },
  	{ "xz",                   0, 'J' },
  	{ "zstd",                 0, OPTION_ZSTD },
  	{ NULL, 0, 0 }
  };
  
  /*
   * This getopt implementation has two key features that common
   * getopt_long() implementations lack.  Apart from those, it's a
   * straightforward option parser, considerably simplified by not
   * needing to support the wealth of exotic getopt_long() features.  It
   * has, of course, been shamelessly tailored for bsdtar.  (If you're
   * looking for a generic getopt_long() implementation for your
   * project, I recommend Gregory Pietsch's public domain getopt_long()
   * implementation.)  The two additional features are:
   *
   * Old-style tar arguments: The original tar implementation treated
   * the first argument word as a list of single-character option
   * letters.  All arguments follow as separate words.  For example,
   *    tar xbf 32 /dev/tape
   * Here, the "xbf" is three option letters, "32" is the argument for
   * "b" and "/dev/tape" is the argument for "f".  We support this usage
   * if the first command-line argument does not begin with '-'.  We
   * also allow regular short and long options to follow, e.g.,
   *    tar xbf 32 /dev/tape -P --format=pax
   *
   * -W long options: There's an obscure GNU convention (only rarely
   * supported even there) that allows "-W option=argument" as an
   * alternative way to support long options.  This was supported in
   * early bsdtar as a way to access long options on platforms that did
   * not support getopt_long() and is preserved here for backwards
   * compatibility.  (Of course, if I'd started with a custom
   * command-line parser from the beginning, I would have had normal
   * long option support on every platform so that hack wouldn't have
   * been necessary.  Oh, well.  Some mistakes you just have to live
   * with.)
   *
   * TODO: We should be able to use this to pull files and intermingled
   * options (such as -C) from the command line in write mode.  That
   * will require a little rethinking of the argument handling in
   * bsdtar.c.
   *
   * TODO: If we want to support arbitrary command-line options from -T
   * input (as GNU tar does), we may need to extend this to handle option
   * words from sources other than argv/argc.  I'm not really sure if I
   * like that feature of GNU tar, so it's certainly not a priority.
   */
  
  int
  bsdtar_getopt(struct bsdtar *bsdtar)
  {
  	enum { state_start = 0, state_old_tar, state_next_word,
  	       state_short, state_long };
  
  	const struct bsdtar_option *popt, *match = NULL, *match2 = NULL;
  	const char *p, *long_prefix = "--";
  	size_t optlength;
  	int opt = '?';
  	int required = 0;
  
  	bsdtar->argument = NULL;
  
  	/* First time through, initialize everything. */
  	if (bsdtar->getopt_state == state_start) {
  		/* Skip program name. */
  		++bsdtar->argv;
  		--bsdtar->argc;
  		if (*bsdtar->argv == NULL)
  			return (-1);
  		/* Decide between "new style" and "old style" arguments. */
  		if (bsdtar->argv[0][0] == '-') {
  			bsdtar->getopt_state = state_next_word;
  		} else {
  			bsdtar->getopt_state = state_old_tar;
  			bsdtar->getopt_word = *bsdtar->argv++;
  			--bsdtar->argc;
  		}
  	}
  
  	/*
  	 * We're parsing old-style tar arguments
  	 */
  	if (bsdtar->getopt_state == state_old_tar) {
  		/* Get the next option character. */
  		opt = *bsdtar->getopt_word++;
  		if (opt == '\0') {
  			/* New-style args can follow old-style. */
  			bsdtar->getopt_state = state_next_word;
  		} else {
  			/* See if it takes an argument. */
  			p = strchr(short_options, opt);
  			if (p == NULL)
  				return ('?');
  			if (p[1] == ':') {
  				bsdtar->argument = *bsdtar->argv;
  				if (bsdtar->argument == NULL) {
  					lafe_warnc(0,
  					    "Option %c requires an argument",
  					    opt);
  					return ('?');
  				}
  				++bsdtar->argv;
  				--bsdtar->argc;
  			}
  		}
  	}
  
  	/*
  	 * We're ready to look at the next word in argv.
  	 */
  	if (bsdtar->getopt_state == state_next_word) {
  		/* No more arguments, so no more options. */
  		if (bsdtar->argv[0] == NULL)
  			return (-1);
  		/* Doesn't start with '-', so no more options. */
  		if (bsdtar->argv[0][0] != '-')
  			return (-1);
  		/* "--" marks end of options; consume it and return. */
  		if (strcmp(bsdtar->argv[0], "--") == 0) {
  			++bsdtar->argv;
  			--bsdtar->argc;
  			return (-1);
  		}
  		/* Get next word for parsing. */
  		bsdtar->getopt_word = *bsdtar->argv++;
  		--bsdtar->argc;
  		if (bsdtar->getopt_word[1] == '-') {
  			/* Set up long option parser. */
  			bsdtar->getopt_state = state_long;
  			bsdtar->getopt_word += 2; /* Skip leading '--' */
  		} else {
  			/* Set up short option parser. */
  			bsdtar->getopt_state = state_short;
  			++bsdtar->getopt_word;  /* Skip leading '-' */
  		}
  	}
  
  	/*
  	 * We're parsing a group of POSIX-style single-character options.
  	 */
  	if (bsdtar->getopt_state == state_short) {
  		/* Peel next option off of a group of short options. */
  		opt = *bsdtar->getopt_word++;
  		if (opt == '\0') {
  			/* End of this group; recurse to get next option. */
  			bsdtar->getopt_state = state_next_word;
  			return bsdtar_getopt(bsdtar);
  		}
  
  		/* Does this option take an argument? */
  		p = strchr(short_options, opt);
  		if (p == NULL)
  			return ('?');
  		if (p[1] == ':')
  			required = 1;
  
  		/* If it takes an argument, parse that. */
  		if (required) {
  			/* If arg is run-in, bsdtar->getopt_word already points to it. */
  			if (bsdtar->getopt_word[0] == '\0') {
  				/* Otherwise, pick up the next word. */
  				bsdtar->getopt_word = *bsdtar->argv;
  				if (bsdtar->getopt_word == NULL) {
  					lafe_warnc(0,
  					    "Option -%c requires an argument",
  					    opt);
  					return ('?');
  				}
  				++bsdtar->argv;
  				--bsdtar->argc;
  			}
  			if (opt == 'W') {
  				bsdtar->getopt_state = state_long;
  				long_prefix = "-W "; /* For clearer errors. */
  			} else {
  				bsdtar->getopt_state = state_next_word;
  				bsdtar->argument = bsdtar->getopt_word;
  			}
  		}
  	}
  
  	/* We're reading a long option, including -W long=arg convention. */
  	if (bsdtar->getopt_state == state_long) {
  		/* After this long option, we'll be starting a new word. */
  		bsdtar->getopt_state = state_next_word;
  
  		/* Option name ends at '=' if there is one. */
  		p = strchr(bsdtar->getopt_word, '=');
  		if (p != NULL) {
  			optlength = (size_t)(p - bsdtar->getopt_word);
  			bsdtar->argument = (char *)(uintptr_t)(p + 1);
  		} else {
  			optlength = strlen(bsdtar->getopt_word);
  		}
  
  		/* Search the table for an unambiguous match. */
  		for (popt = tar_longopts; popt->name != NULL; popt++) {
  			/* Short-circuit if first chars don't match. */
  			if (popt->name[0] != bsdtar->getopt_word[0])
  				continue;
  			/* If option is a prefix of name in table, record it.*/
  			if (strncmp(bsdtar->getopt_word, popt->name, optlength) == 0) {
  				match2 = match; /* Record up to two matches. */
  				match = popt;
  				/* If it's an exact match, we're done. */
  				if (strlen(popt->name) == optlength) {
  					match2 = NULL; /* Forget the others. */
  					break;
  				}
  			}
  		}
  
  		/* Fail if there wasn't a unique match. */
  		if (match == NULL) {
  			lafe_warnc(0,
  			    "Option %s%s is not supported",
  			    long_prefix, bsdtar->getopt_word);
  			return ('?');
  		}
  		if (match2 != NULL) {
  			lafe_warnc(0,
  			    "Ambiguous option %s%s (matches --%s and --%s)",
  			    long_prefix, bsdtar->getopt_word, match->name, match2->name);
  			return ('?');
  		}
  
  		/* We've found a unique match; does it need an argument? */
  		if (match->required) {
  			/* Argument required: get next word if necessary. */
  			if (bsdtar->argument == NULL) {
  				bsdtar->argument = *bsdtar->argv;
  				if (bsdtar->argument == NULL) {
  					lafe_warnc(0,
  					    "Option %s%s requires an argument",
  					    long_prefix, match->name);
  					return ('?');
  				}
  				++bsdtar->argv;
  				--bsdtar->argc;
  			}
  		} else {
  			/* Argument forbidden: fail if there is one. */
  			if (bsdtar->argument != NULL) {
  				lafe_warnc(0,
  				    "Option %s%s does not allow an argument",
  				    long_prefix, match->name);
  				return ('?');
  			}
  		}
  		return (match->equivalent);
  	}
  
  	return (opt);
  }
  