/* vi: set sw=4 ts=4: */
/*
 * getopt.c - Enhanced implementation of BSD getopt(1)
 * Copyright (c) 1997, 1998, 1999, 2000  Frodo Looijaard <frodol@dds.nl>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
/*
 * Version 1.0-b4: Tue Sep 23 1997. First public release.
 * Version 1.0: Wed Nov 19 1997.
 *   Bumped up the version number to 1.0
 *   Fixed minor typo (CSH instead of TCSH)
 * Version 1.0.1: Tue Jun 3 1998
 *   Fixed sizeof instead of strlen bug
 *   Bumped up the version number to 1.0.1
 * Version 1.0.2: Thu Jun 11 1998 (not present)
 *   Fixed gcc-2.8.1 warnings
 *   Fixed --version/-V option (not present)
 * Version 1.0.5: Tue Jun 22 1999
 *   Make -u option work (not present)
 * Version 1.0.6: Tue Jun 27 2000
 *   No important changes
 * Version 1.1.0: Tue Jun 30 2000
 *   Added NLS support (partly written by Arkadiusz Mickiewicz
 *     <misiek@misiek.eu.org>)
 * Ported to Busybox - Alfred M. Szmidt <ams@trillian.itslinux.org>
 *  Removed --version/-V and --help/-h
 *  Removed parse_error(), using bb_error_msg() from Busybox instead
 *  Replaced our_malloc with xmalloc and our_realloc with xrealloc
 */
//config:config GETOPT
//config:       bool "getopt (5.8 kb)"
//config:       default y
//config:       help
//config:       The getopt utility is used to break up (parse) options in command
//config:       lines to make it easy to write complex shell scripts that also check
//config:       for legal (and illegal) options. If you want to write horribly
//config:       complex shell scripts, or use some horribly complex shell script
//config:       written by others, this utility may be for you. Most people will
//config:       wisely leave this disabled.
//config:
//config:config FEATURE_GETOPT_LONG
//config:       bool "Support -l LONGOPTs"
//config:       default y
//config:       depends on GETOPT && LONG_OPTS
//config:       help
//config:       Enable support for long options (option -l).

//applet:IF_GETOPT(APPLET_NOEXEC(getopt, getopt, BB_DIR_BIN, BB_SUID_DROP, getopt))

//kbuild:lib-$(CONFIG_GETOPT) += getopt.o

//usage:#define getopt_trivial_usage
//usage:       "[OPTIONS] [--] OPTSTRING PARAMS"
//usage:#define getopt_full_usage "\n\n"
//usage:        IF_FEATURE_GETOPT_LONG(
//usage:       "        -a              Allow long options starting with single -\n"
//usage:       "        -l LOPT[,...]   Long options to recognize\n"
//usage:        )
//usage:       "        -n PROGNAME     The name under which errors are reported"
//usage:     "\n        -o OPTSTRING    Short options to recognize"
//usage:     "\n        -q              No error messages on unrecognized options"
//usage:     "\n        -Q              No normal output"
//usage:     "\n        -s SHELL        Set shell quoting conventions"
//usage:     "\n        -T              Version test (exits with 4)"
//usage:     "\n        -u              Don't quote output"
//usage:        IF_FEATURE_GETOPT_LONG( /* example uses -l, needs FEATURE_GETOPT_LONG */
//usage:     "\n"
//usage:     "\nExample:"
//usage:     "\n"
//usage:     "\nO=`getopt -l bb: -- ab:c:: \"$@\"` || exit 1"
//usage:     "\neval set -- \"$O\""
//usage:     "\nwhile true; do"
//usage:     "\n        case \"$1\" in"
//usage:     "\n        -a)     echo A; shift;;"
//usage:     "\n        -b|--bb) echo \"B:'$2'\"; shift 2;;"
//usage:     "\n        -c)     case \"$2\" in"
//usage:     "\n                \"\")   echo C; shift 2;;"
//usage:     "\n                *)      echo \"C:'$2'\"; shift 2;;"
//usage:     "\n                esac;;"
//usage:     "\n        --)     shift; break;;"
//usage:     "\n        *)      echo Error; exit 1;;"
//usage:     "\n        esac"
//usage:     "\ndone"
//usage:        )
//usage:
//usage:#define getopt_example_usage
//usage:       "$ cat getopt.test\n"
//usage:       "#!/bin/sh\n"
//usage:       "GETOPT=`getopt -o ab:c:: --long a-long,b-long:,c-long:: \\\n"
//usage:       "       -n 'example.busybox' -- \"$@\"`\n"
//usage:       "if [ $? != 0 ]; then exit 1; fi\n"
//usage:       "eval set -- \"$GETOPT\"\n"
//usage:       "while true; do\n"
//usage:       " case $1 in\n"
//usage:       "   -a|--a-long) echo \"Option a\"; shift;;\n"
//usage:       "   -b|--b-long) echo \"Option b, argument '$2'\"; shift 2;;\n"
//usage:       "   -c|--c-long)\n"
//usage:       "     case \"$2\" in\n"
//usage:       "       \"\") echo \"Option c, no argument\"; shift 2;;\n"
//usage:       "       *)  echo \"Option c, argument '$2'\"; shift 2;;\n"
//usage:       "     esac;;\n"
//usage:       "   --) shift; break;;\n"
//usage:       "   *) echo \"Internal error!\"; exit 1;;\n"
//usage:       " esac\n"
//usage:       "done\n"

#if ENABLE_FEATURE_GETOPT_LONG
# include <getopt.h>
#endif
#include "libbb.h"

/* NON_OPT is the code that is returned when a non-option is found in '+'
   mode */
enum {
        NON_OPT = 1,
#if ENABLE_FEATURE_GETOPT_LONG
/* LONG_OPT is the code that is returned when a long option is found. */
        LONG_OPT = 2
#endif
};

/* For finding activated option flags. Must match getopt32 call! */
enum {
        OPT_o   = 0x1,  // -o
        OPT_n   = 0x2,  // -n
        OPT_q   = 0x4,  // -q
        OPT_Q   = 0x8,  // -Q
        OPT_s   = 0x10, // -s
        OPT_T   = 0x20, // -T
        OPT_u   = 0x40, // -u
#if ENABLE_FEATURE_GETOPT_LONG
        OPT_a   = 0x80, // -a
        OPT_l   = 0x100, // -l
#endif
        SHELL_IS_TCSH = 0x8000, /* hijack this bit for other purposes */
};

/* 0 is getopt_long, 1 is getopt_long_only */
#define alternative  (option_mask32 & OPT_a)

#define quiet_errors (option_mask32 & OPT_q)
#define quiet_output (option_mask32 & OPT_Q)
#define quote        (!(option_mask32 & OPT_u))
#define shell_TCSH   (option_mask32 & SHELL_IS_TCSH)

/*
 * This function 'normalizes' a single argument: it puts single quotes around
 * it and escapes other special characters. If quote is false, it just
 * returns its argument.
 * Bash only needs special treatment for single quotes; tcsh also recognizes
 * exclamation marks within single quotes, and nukes whitespace.
 * This function returns a pointer to a buffer that is overwritten by
 * each call.
 */
static const char *normalize(const char *arg)
{
        char *bufptr;
        char *BUFFER;

        if (!quote) { /* Just return arg */
                return arg;
        }

        /* Each character in arg may take up to four characters in the result:
           For a quote we need a closing quote, a backslash, a quote and an
           opening quote! We need also the global opening and closing quote,
           and one extra character for '\0'. */
        BUFFER = auto_string(xmalloc(strlen(arg)*4 + 3));

        bufptr = BUFFER;
        *bufptr ++= '\'';

        while (*arg) {
                if (shell_TCSH && *arg == '\n') {
                        /* Newline: replace it with: \n */
                        *bufptr++ = '\\';
                        *bufptr++ = 'n';
                } else
                if ((shell_TCSH && (*arg == '!' || isspace(*arg)))
                 || *arg == '\''
                ) {
                        /* Quote exclamation marks, non-NL whitespace and quotes */
                        *bufptr++ = '\'';
                        *bufptr++ = '\\';
                        *bufptr++ = *arg;
                        *bufptr++ = '\'';
                } else {
                        /* Just copy */
                        *bufptr ++= *arg;
                }
                arg++;
        }
        *bufptr++ = '\'';
        *bufptr++ = '\0';
        return BUFFER;
}

/*
 * Generate the output. argv[0] is the program name (used for reporting errors).
 * argv[1..] contains the options to be parsed. argc must be the number of
 * elements in argv (ie. 1 if there are no options, only the program name),
 * optstr must contain the short options, and longopts the long options.
 * Other settings are found in global variables.
 */
#if !ENABLE_FEATURE_GETOPT_LONG
#define generate_output(argv,argc,optstr,longopts) \
        generate_output(argv,argc,optstr)
#endif
static int generate_output(char **argv, int argc, const char *optstr, const struct option *longopts)
{
        int exit_code = 0; /* We assume everything will be OK */

        if (quiet_errors) /* No error reporting from getopt(3) */
                opterr = 0;

        /* We used it already in main() in getopt32(),
         * we *must* reset getopt(3): */
        GETOPT_RESET();

        while (1) {
#if ENABLE_FEATURE_GETOPT_LONG
                int longindex;
                int opt = alternative
                        ? getopt_long_only(argc, argv, optstr, longopts, &longindex)
                        : getopt_long(argc, argv, optstr, longopts, &longindex)
                ;
#else
                int opt = getopt(argc, argv, optstr);
#endif
                if (opt == -1)
                        break;
                if (opt == '?' || opt == ':' )
                        exit_code = 1;
                else if (!quiet_output) {
#if ENABLE_FEATURE_GETOPT_LONG
                        if (opt == LONG_OPT) {
                                printf(" --%s", longopts[longindex].name);
                                if (longopts[longindex].has_arg)
                                        printf(" %s",
                                                normalize(optarg ? optarg : ""));
                        } else
#endif
                        if (opt == NON_OPT)
                                printf(" %s", normalize(optarg));
                        else {
                                const char *charptr;
                                printf(" -%c", opt);
                                charptr = strchr(optstr, opt);
                                if (charptr && *++charptr == ':')
                                        printf(" %s",
                                                normalize(optarg ? optarg : ""));
                        }
                }
        }

        if (!quiet_output) {
                unsigned idx;
                printf(" --");
                idx = optind;
                while (argv[idx])
                        printf(" %s", normalize(argv[idx++]));
                bb_putchar('\n');
        }
        return exit_code;
}

#if ENABLE_FEATURE_GETOPT_LONG
/*
 * Register several long options. options is a string of long options,
 * separated by commas or whitespace.
 * This nukes options!
 */
static struct option *add_long_options(struct option *long_options, char *options)
{
        int long_nr = 0;
        int arg_opt, tlen;
        char *tokptr;

        if (long_options)
                while (long_options[long_nr].name)
                        long_nr++;

        tokptr = strtok_r(options, ", \t\n", &options);
        while (tokptr) {
                arg_opt = no_argument;
                tlen = strlen(tokptr);
                if (tlen) {
                        tlen--;
                        if (tokptr[tlen] == ':') {
                                arg_opt = required_argument;
                                if (tlen && tokptr[tlen-1] == ':') {
                                        tlen--;
                                        arg_opt = optional_argument;
                                }
                                tokptr[tlen] = '\0';
                                if (tlen == 0)
                                        bb_simple_error_msg_and_die("empty long option specified");
                        }
                        long_options = xrealloc_vector(long_options, 4, long_nr);
                        long_options[long_nr].has_arg = arg_opt;
                        /*long_options[long_nr].flag = NULL; - xrealloc_vector did it */
                        long_options[long_nr].val = LONG_OPT;
                        long_options[long_nr].name = xstrdup(tokptr);
                        long_nr++;
                        /*memset(&long_options[long_nr], 0, sizeof(long_options[0])); - xrealloc_vector did it */
                }
                tokptr = strtok_r(NULL, ", \t\n", &options);
        }
        return long_options;
}
#endif

static void set_shell(const char *new_shell)
{
        switch (index_in_strings("bash\0sh\0tcsh\0csh\0", new_shell)) {
        case 0:
        case 1:
                break;
        case 2:
        case 3:
                option_mask32 |= SHELL_IS_TCSH;
                break;
        default:
                bb_error_msg("unknown shell '%s', assuming bash", new_shell);
                break;
        }
}


/* Exit codes:
 *   0) No errors, successful operation.
 *   1) getopt(3) returned an error.
 *   2) A problem with parameter parsing for getopt(1).
 *   3) Internal error, out of memory
 *   4) Returned for -T
 */

#if ENABLE_FEATURE_GETOPT_LONG
static const char getopt_longopts[] ALIGN1 =
        "options\0"      Required_argument "o"
        "longoptions\0"  Required_argument "l"
        "quiet\0"        No_argument       "q"
        "quiet-output\0" No_argument       "Q"
        "shell\0"        Required_argument "s"
        "test\0"         No_argument       "T"
        "unquoted\0"     No_argument       "u"
        "alternative\0"  No_argument       "a"
        "name\0"         Required_argument "n"
        ;
#endif

int getopt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int getopt_main(int argc, char **argv)
{
        int n;
        char *optstr = NULL;
        char *name = NULL;
        unsigned opt;
        const char *compatible;
        char *s_arg;
#if ENABLE_FEATURE_GETOPT_LONG
        struct option *long_options = NULL;
        llist_t *l_arg = NULL;
#endif

        compatible = getenv("GETOPT_COMPATIBLE"); /* used as yes/no flag */

        if (!argv[1]) {
                if (compatible) {
                        /* For some reason, the original getopt gave no error
                         * when there were no arguments. */
                        puts(" --");
                        return 0;
                }
                bb_simple_error_msg_and_die("missing optstring argument");
        }

        if (argv[1][0] != '-' || compatible) {
                char *s = argv[1];

                option_mask32 |= OPT_u; /* quoting off */
                s = xstrdup(s + strspn(s, "-+"));
                argv[1] = argv[0];
                return generate_output(argv+1, argc-1, s, long_options);
        }

#if !ENABLE_FEATURE_GETOPT_LONG
        opt = getopt32(argv, "+o:n:qQs:Tu", &optstr, &name, &s_arg);
#else
        opt = getopt32long(argv, "+o:n:qQs:Tual:*", getopt_longopts,
                                        &optstr, &name, &s_arg, &l_arg);
        /* Effectuate the read options for the applet itself */
        while (l_arg) {
                long_options = add_long_options(long_options, llist_pop(&l_arg));
        }
#endif

        if (opt & OPT_s) {
                set_shell(s_arg);
        }

        if (opt & OPT_T) {
                return 4;
        }

        /* All options controlling the applet have now been parsed */
        n = optind - 1;
        if (!optstr) {
                optstr = argv[++n];
                if (!optstr)
                        bb_simple_error_msg_and_die("missing optstring argument");
        }

        argv[n] = name ? name : argv[0];
        return generate_output(argv + n, argc - n, optstr, long_options);
}