/∗ Getopt for GNU. Copyright (C) 1987, 1989 Free Software Foundation, Inc.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 1, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. ∗/ /∗ This version of ‘getopt’ appears to the caller like standard Unix ‘getopt’

but it behaves differently for the user, since it allows the user

to intersperse the options with the other arguments.

As ‘getopt’ works, it permutes the elements of ‘argv’ so that,

when it is done, all the options precede everything else. Thus

all application programs are extended to handle flexible argument order.

Setting the environment variable POSIX OPTION ORDER disables permutation. Then the behavior is completely standard.

GNU application programs can use a third alternative mode in which

they can distinguish the relative order of options and other arguments. ∗/

#include <stdio.h>

/∗ If compiled with GNU C, use the built-in alloca ∗/

#ifdef GNUC

#define alloca builtin alloca #else /∗ not GNUC ∗/

#ifdef sparc
#include <alloca.h>
#else

char ∗alloca ();

#endif

#endif /∗ not GNUC ∗/

#ifdef USG

#define bcopy(s, d, l) memcpy((d), (s), (l)) #define index strchr

#endif

char ∗getenv (); char ∗index (); char ∗malloc ();

/∗ For communication from ‘getopt’ to the caller.

When ‘getopt’ finds an option that takes an argument,

the argument value is returned here.

Also, when ‘ordering’ is RETURN IN ORDER,

each non-option ARGV-element is returned here. ∗/

char ∗optarg = 0;

/∗ Index in ARGV of the next element to be scanned.

This is used for communication to and from the caller

and for communication between successive calls to ‘getopt’.

On entry to ‘getopt’, zero means this is the first call; initialize.

When ‘getopt’ returns EOF, this is the index of the first of the non-option elements that the caller should itself scan.

Otherwise, ‘optind’ communicates from one call to the next how much of ARGV has been scanned so far. ∗/

int optind = 0;

/∗ The next char to be scanned in the option-element in which the last option character we returned was found. This allows us to pick up the scan where we left off.

If this is zero, or a null string, it means resume the scan by advancing to the next ARGV-element. ∗/

static char ∗nextchar;

/∗ Callers store zero here to inhibit the error message for unrecognized options. ∗/

int opterr = 1;

/∗ Describe how to deal with options that follow non-option ARGV-elements.

If the caller did not specify anything, the default is REQUIRE ORDER if the environment variable POSIX OPTION ORDER is defined, PERMUTE otherwise.

REQUIRE ORDER means don’t recognize them as options. Stop option processing when the first non-option is seen. This is what Unix does.

PERMUTE is the default. We permute the contents of ARGV as we scan, so that eventually all the options are at the end. This allows options to be given in any order, even with programs that were not written to expect this.

RETURN IN ORDER is an option available to programs that were written to expect options and other ARGV-elements in any order and that care about the ordering of the two. We describe each non-option ARGV-element as if it were the argument of an option with character code one. Using ‘-’ as the first character of the list of option characters requests this mode of operation.

The special argument ‘–’ forces an end of option-scanning regardless of the value of ‘ordering’. In the case of RETURN IN ORDER, only ‘–’ can cause ‘getopt’ to return EOF with ‘optind’ != ARGC. ∗/

static enum { REQUIRE ORDER, PERMUTE, RETURN IN ORDER } ordering;

/∗ Describe the long-named options requested by the application.

GETOPT LONG OPTIONS is a vector of ‘struct option’ terminated by an element containing a name which is zero. The field ‘has arg’ is 1 if the option takes an argument, 2 if it takes an optional argument. ∗/

struct option {

char ∗name; int has arg; int ∗flag; int val;

};

struct option ∗ getopt long options;

int getopt long only = 0;

#if 0

/∗ This is an ugly kludge. Programs should use the opt index argument

to getopt long instead. ∗/ /∗ Name of long-named option actually found. ∗/

char ∗ getopt option name;

#endif

/∗ Index in GETOPT LONG OPTIONS of the long-named option actually found. Only valid when a long-named option was found. ∗/

int option index; /∗ Handle permutation of arguments. ∗/

/∗ Describe the part of ARGV that contains non-options that have been skipped. ‘first nonopt’ is the index in ARGV of the first of them; ‘last nonopt’ is the index after the last of them. ∗/

static int first nonopt; static int last nonopt;

/∗ Exchange two adjacent subsequences of ARGV.

One subsequence is elements [first nonopt,last nonopt)

which contains all the non-options that have been skipped so far.

The other is elements [last nonopt,optind), which contains all the options processed since those non-options were skipped.

‘first nonopt’ and ‘last nonopt’ are relocated so that they describe the new indices of the non-options in ARGV after they are moved. ∗/

static void exchange (argv)

char ∗∗argv; {

int nonopts size

= (last nonopt - first nonopt) ∗ sizeof (char ∗); char ∗∗temp = (char ∗∗) alloca (nonopts size);

/∗ Interchange the two blocks of data in argv. ∗/

bcopy (&argv[first nonopt], temp, nonopts size);

bcopy (&argv[last nonopt], &argv[first nonopt],

(optind - last nonopt) ∗ sizeof (char ∗)); bcopy (temp, &argv[first nonopt + optind - last nonopt],

nonopts size);

/∗ Update records for the slots the non-options now occupy. ∗/

first nonopt += (optind - last nonopt);

last nonopt = optind; } /∗ Scan elements of ARGV (whose length is ARGC) for option characters

given in OPTSTRING.

If an element of ARGV starts with ’-’, and is not exactly ”-” or ”–”, then it is an option element. The characters of this element (aside from the initial ’-’) are option characters. If ‘getopt’ is called repeatedly, it returns successively each of the option characters from each of the option elements.

If ‘getopt’ finds another option character, it returns that character, updating ‘optind’ and ‘nextchar’ so that the next call to ‘getopt’ can resume the scan with the following option character or ARGV-element.

If there are no more option characters, ‘getopt’ returns ‘EOF’. Then ‘optind’ is the index in ARGV of the first ARGV-element that is not an option. (The ARGV-elements have been permuted so that those that are not options now come last.)

OPTSTRING is a string containing the legitimate option characters. If an option character is seen that is not listed in OPTSTRING, return ’?’ after printing an error message. If you set ‘opterr’ to zero, the error message is suppressed but we still return ’?’.

If a char in OPTSTRING is followed by a colon, that means it wants an arg, so the following text in the same ARGV-element, or the text of the following ARGV-element, is returned in ‘optarg’. Two colons mean an option that wants an optional arg; if there is text in the current ARGV-element, it is returned in ‘optarg’, otherwise ‘optarg’ is set to zero.

If OPTSTRING starts with ‘-’, it requests a different method of handling the non-option ARGV-elements. See the comments about RETURN IN ORDER, above.

Long-named options begin with ‘+’ instead of ‘-’. Their names may be abbreviated as long as the abbreviation is unique or is an exact match for some defined option. If they have an argument, it follows the option name in the same ARGV-element, separated from the option name by a ‘=’, or else the in next ARGV-element. ‘getopt’ returns 0 when it finds a long-named option. ∗/

int getopt (argc, argv, optstring)

int argc;

char ∗∗argv;

char ∗optstring; {

optarg = 0; /∗ Initialize the internal data when the first call is made.

Start processing options with ARGV-element 1 (since ARGV-element 0 is the program name); the sequence of previously skipped non-option ARGV-elements is empty. ∗/

if (optind == 0)

{ first nonopt = last nonopt = optind = 1;

nextchar = 0;

/∗ Determine how to handle the ordering of options and nonoptions. ∗/

if (optstring[0] == ’-’)

ordering = RETURN IN ORDER;

else if (getenv (" POSIX OPTION ORDER") ≠ 0)

ordering = REQUIRE ORDER; else

ordering = PERMUTE; }

if (nextchar == 0 || ∗nextchar == 0)

{

if (ordering == PERMUTE)

{

/∗ If we have just processed some options following some non-options, exchange them so that the options come first. ∗/

if (first nonopt ≠ last nonopt && last nonopt ≠ optind)

exchange (argv); else if (last nonopt ≠ optind) first nonopt = optind;

/∗ Now skip any additional non-options and extend the range of non-options previously skipped. ∗/

while (optind < argc

&& (argv[optind][0] ≠ ’-’

|| argv[optind][1] == 0) && ( getopt long options == 0 || argv[optind][0] ≠ ’+’ || argv[optind][1] == 0))

optind++; last nonopt = optind;

}

/∗ Special ARGV-element ‘–’ means premature end of options.

Skip it like a null option, then exchange with previous non-options as if it were an option, then skip everything else like a non-option. ∗/

if (optind ≠ argc && !strcmp (argv[optind], "--"))

{ optind++;

if (first nonopt ≠ last nonopt && last nonopt ≠ optind)

exchange (argv); else if (first nonopt == last nonopt)

first nonopt = optind; last nonopt = argc;

optind = argc; }

/∗ If we have done all the ARGV-elements, stop the scan and back over any non-options that we skipped and permuted. ∗/

if (optind == argc)

{

/∗ Set the next-arg-index to point at the non-options

that we previously skipped, so the caller will digest them. ∗/ if (first nonopt ≠ last nonopt)

optind = first nonopt; return EOF;

}

/∗ If we have come to a non-option and did not permute it, either stop the scan or describe it to the caller and pass it by. ∗/

if ((argv[optind][0] ≠ ’-’ || argv[optind][1] == 0)

&& ( getopt long options == 0

|| argv[optind][0] ≠ ’+’ || argv[optind][1] == 0)) {

if (ordering == REQUIRE ORDER)

return EOF; optarg = argv[optind++];

#if 0

getopt option name = 0;

#endif

return 1; }

/∗ We have found another option-ARGV-element.

Start decoding its characters. ∗/

nextchar = argv[optind] + 1; }

if ( getopt long options ≠ 0

&& (argv[optind][0] == ’+’

|| ( getopt long only && argv[optind][0] == ’-’)) )

{ struct option ∗p; char ∗s = nextchar; int exact = 0; int ambig = 0; struct option ∗pfound = 0; int indfound;

while (∗s && ∗s ≠ ’=’) s++;

/∗ Test all options for either exact match or abbreviated matches. ∗/ for (p = getopt long options, option index = 0; p→name;

p++, option index++) if (!strncmp (p→name, nextchar, s - nextchar))

{

if (s - nextchar == strlen (p→name))

{ /∗ Exact match found. ∗/ pfound = p; indfound = option index; exact = 1; break;

} else if (pfound == 0)

{ /∗ First nonexact match found. ∗/ pfound = p; indfound = option index;

} else

/∗ Second nonexact match found. ∗/ ambig = 1;

}

if (ambig && !exact)

{

    fprintf (stderr, "%s:  option `%s' is ambiguous\n",

argv[0], argv[optind]);

nextchar += strlen (nextchar);

return ’?’; }

if (pfound ≠ 0)

{ option index = indfound; optind++; if (∗s)

{

if (pfound→has arg > 0) optarg = s + 1;

else {

fprintf (stderr,

                "%s:  option `%c%s' doesn't allow an argument\n",

argv[0], argv[optind - 1][0], pfound→name);

nextchar += strlen (nextchar);

return ’?’; }

} else if (pfound→has arg)

{

if (optind < argc)

optarg = argv[optind++]; else if (pfound→has arg ≠ 2)

{

        fprintf (stderr, "%s:  option `%s' requires an argument\n",

argv[0], argv[optind - 1]);

nextchar += strlen (nextchar);

return ’?’; }

}

#if 0

getopt option name = pfound→name;

#endif

nextchar += strlen (nextchar); if (pfound→flag)

∗(pfound→flag) = pfound→val; return 0;

} /∗ Can’t find it as a long option. If this is getopt long only,

and the option starts with ’-’ and is a valid short option, then interpret it as a short option. Otherwise it’s an error. ∗/

if ( getopt long only == 0 || argv[optind][0] == ’+’ ||

index (optstring, ∗nextchar) == 0) { if (opterr ≠ 0)

  fprintf (stderr, "%s:  unrecognized option `%c%s'\n",

argv[0], argv[optind][0], nextchar);

nextchar += strlen (nextchar); return ’?’;

} }

/∗ Look at and handle the next option-character. ∗/

{ char c = ∗nextchar++; char ∗temp = index (optstring, c);

/∗ Increment ‘optind’ when we start to process its last character. ∗/ if (∗nextchar == 0)

optind++;

if (temp == 0 || c == ’:’)

{

if (opterr ≠ 0)

{

if (c < 040 || c ≥ 0177)

    fprintf (stderr, "%s:  unrecognized option, character code
0%o\n",

argv[0], c);

else

    fprintf (stderr, "%s:  unrecognized option `-%c'\n",

argv[0], c);

} return ’?’;

} if (temp[1] == ’:’)

{

if (temp[2] == ’:’)

{ /∗ This is an option that accepts an argument optionally. ∗/ if (∗nextchar ≠ 0)

{ optarg = nextchar; optind++;

} else

optarg = 0; nextchar = 0;

} else {

/∗ This is an option that requires an argument. ∗/ if (∗nextchar ≠ 0)

{ optarg = nextchar; /∗ If we end this ARGV-element by taking the rest as an arg,

we must advance to the next element now. ∗/ optind++;

} else if (optind == argc)

{

if (opterr ≠ 0)

    fprintf (stderr, "%s:  option `-%c' requires an argument\n",

argv[0], c);

c = ’?’; }

else

/∗ We already incremented ‘optind’ once;

increment it again when taking next ARGV-elt as argument. ∗/ optarg = argv[optind++];

nextchar = 0; }

} return c;

} }

#ifdef TEST

/∗ Compile with -DTEST to make an executable for use in testing the above definition of ‘getopt’. ∗/

int main (argc, argv)

int argc; char ∗∗argv;

{ char c; int digit optind = 0;

while (1)

{ int this option optind = optind; if ((c = getopt (argc, argv, "abc:d:0123456789")) == EOF)

break;

switch (c)

{ case ’0’: case ’1’: case ’2’: case ’3’: case ’4’: case ’5’: case ’6’: case ’7’: case ’8’: case ’9’:

if (digit optind ≠ 0 && digit optind ≠ this option optind)

    printf ("digits occur in two different argv-elements.\n");

digit optind = this option optind;

printf ("option %c\n", c);

break;

case ’a’:

  printf ("option a\n");

break;

case ’b’:

  printf ("option b\n");

break;

case ’c’:

  printf ("option c with value `%s'\n", optarg);

break;

case ’?’:

break;

default:

  printf ("??  getopt returned character code 0%o ??\n", c);

} }

if (optind < argc)

{

printf ("non-option ARGV-elements:  ");

while (optind < argc)

printf ("%s ", argv[optind++]); printf ("\n");

}

return 0; }

#endif /∗ TEST ∗/