2006-09-01 Marcus Brinkmann <marcus@g10code.de>

[gnupg.git] / jnlib / argparse.c

/* [argparse.c wk 17.06.97] Argument Parser for option handling
 *      Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
 *
 * This file is part of GnuPG.
 *
 * GnuPG 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 2 of the License, or
 * (at your option) any later version.
 *
 * GnuPG 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 * USA.
 */

#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>

#include "libjnlib-config.h"
#include "mischelp.h"
#include "stringhelp.h"
#include "logging.h"
#include "argparse.h"


/*********************************
 * @Summary arg_parse
 *  #include <wk/lib.h>
 *
 *  typedef struct {
 *      char *argc;               pointer to argc (value subject to change)
 *      char ***argv;             pointer to argv (value subject to change)
 *      unsigned flags;           Global flags (DO NOT CHANGE)
 *      int err;                  print error about last option
 *                                1 = warning, 2 = abort
 *      int r_opt;                return option
 *      int r_type;               type of return value (0 = no argument found)
 *      union {
 *          int   ret_int;
 *          long  ret_long
 *          ulong ret_ulong;
 *          char *ret_str;
 *      } r;                      Return values
 *      struct {
 *          int idx;
 *          const char *last;
 *          void *aliases;
 *      } internal;               DO NOT CHANGE
 *  } ARGPARSE_ARGS;
 *
 *  typedef struct {
 *      int         short_opt;
 *      const char *long_opt;
 *      unsigned flags;
 *  } ARGPARSE_OPTS;
 *
 *  int arg_parse( ARGPARSE_ARGS *arg, ARGPARSE_OPTS *opts );
 *
 * @Description
 *  This is my replacement for getopt(). See the example for a typical usage.
 *  Global flags are:
 *     Bit 0 : Do not remove options form argv
 *     Bit 1 : Do not stop at last option but return other args
 *             with r_opt set to -1.
 *     Bit 2 : Assume options and real args are mixed.
 *     Bit 3 : Do not use -- to stop option processing.
 *     Bit 4 : Do not skip the first arg.
 *     Bit 5 : allow usage of long option with only one dash
 *     Bit 6 : ignore --version
 *     all other bits must be set to zero, this value is modified by the
 *     function, so assume this is write only.
 *  Local flags (for each option):
 *     Bit 2-0 : 0 = does not take an argument
 *               1 = takes int argument
 *               2 = takes string argument
 *               3 = takes long argument
 *               4 = takes ulong argument
 *     Bit 3 : argument is optional (r_type will the be set to 0)
 *     Bit 4 : allow 0x etc. prefixed values.
 *     Bit 7 : this is a command and not an option
 *  You stop the option processing by setting opts to NULL, the function will
 *  then return 0.
 * @Return Value
 *   Returns the args.r_opt or 0 if ready
 *   r_opt may be -2/-7 to indicate an unknown option/command.
 * @See Also
 *   ArgExpand
 * @Notes
 *  You do not need to process the options 'h', '--help' or '--version'
 *  because this function includes standard help processing; but if you
 *  specify '-h', '--help' or '--version' you have to do it yourself.
 *  The option '--' stops argument processing; if bit 1 is set the function
 *  continues to return normal arguments.
 *  To process float args or unsigned args you must use a string args and do
 *  the conversion yourself.
 * @Example
 *
 *     ARGPARSE_OPTS opts[] = {
 *     { 'v', "verbose",   0 },
 *     { 'd', "debug",     0 },
 *     { 'o', "output",    2 },
 *     { 'c', "cross-ref", 2|8 },
 *     { 'm', "my-option", 1|8 },
 *     { 500, "have-no-short-option-for-this-long-option", 0 },
 *     {0} };
 *     ARGPARSE_ARGS pargs = { &argc, &argv, 0 }
 *
 *     while( ArgParse( &pargs, &opts) ) {
 *         switch( pargs.r_opt ) {
 *           case 'v': opt.verbose++; break;
 *           case 'd': opt.debug++; break;
 *           case 'o': opt.outfile = pargs.r.ret_str; break;
 *           case 'c': opt.crf = pargs.r_type? pargs.r.ret_str:"a.crf"; break;
 *           case 'm': opt.myopt = pargs.r_type? pargs.r.ret_int : 1; break;
 *           case 500: opt.a_long_one++;  break
 *           default : pargs.err = 1; break; -- force warning output --
 *         }
 *     }
 *     if( argc > 1 )
 *         log_fatal( "Too many args");
 *
 */

typedef struct alias_def_s *ALIAS_DEF;
struct alias_def_s {
    ALIAS_DEF next;
    char *name;   /* malloced buffer with name, \0, value */
    const char *value; /* ptr into name */
};

static const char *(*strusage_handler)( int ) = NULL;

static int  set_opt_arg(ARGPARSE_ARGS *arg, unsigned flags, char *s);
static void show_help(ARGPARSE_OPTS *opts, unsigned flags);
static void show_version(void);


static void
initialize( ARGPARSE_ARGS *arg, const char *filename, unsigned *lineno )
{
    if( !(arg->flags & (1<<15)) ) { /* initialize this instance */
        arg->internal.idx = 0;
        arg->internal.last = NULL;
        arg->internal.inarg = 0;
        arg->internal.stopped = 0;
        arg->internal.aliases = NULL;
        arg->internal.cur_alias = NULL;
        arg->err = 0;
        arg->flags |= 1<<15; /* mark initialized */
        if( *arg->argc < 0 )
            jnlib_log_bug("Invalid argument for ArgParse\n");
    }


    if( arg->err ) { /* last option was erroneous */
        const char *s;

        if( filename ) {
            if( arg->r_opt == -6 )
                s = "argument not expected\n";
            else if( arg->r_opt == -5 )
                s = "read error\n";
            else if( arg->r_opt == -4 )
                s = "keyword too long\n";
            else if( arg->r_opt == -3 )
                s = "missing argument\n";
            else if( arg->r_opt == -7 )
                s = "invalid command\n";
            else if( arg->r_opt == -10 )
                s = "invalid alias definition\n";
            else
                s = "invalid option\n";
            jnlib_log_error("%s:%u: %s\n", filename, *lineno, s);
        }
        else {
            s = arg->internal.last? arg->internal.last:"[??]";
            
            if( arg->r_opt == -3 )
              jnlib_log_error ("Missing argument for option \"%.50s\"\n", s);
            else if( arg->r_opt == -6 )
              jnlib_log_error ("Option \"%.50s\" does not expect an argument\n",
                               s );
            else if( arg->r_opt == -7 )
              jnlib_log_error ("Invalid command \"%.50s\"\n", s);
            else if( arg->r_opt == -8 )
              jnlib_log_error ("Option \"%.50s\" is ambiguous\n", s);
            else if( arg->r_opt == -9 )
              jnlib_log_error ("Command \"%.50s\" is ambiguous\n",s );
            else
              jnlib_log_error ("Invalid option \"%.50s\"\n", s);
        }
        if( arg->err != 1 )
            exit(2);
        arg->err = 0;
    }

    /* clearout the return value union */
    arg->r.ret_str = NULL;
    arg->r.ret_long= 0;
}


static void
store_alias( ARGPARSE_ARGS *arg, char *name, char *value )
{
    /* TODO: replace this dummy function with a rea one
     * and fix the probelms IRIX has with (ALIAS_DEV)arg..
     * used as lvalue
     */
#if 0
    ALIAS_DEF a = jnlib_xmalloc( sizeof *a );
    a->name = name;
    a->value = value;
    a->next = (ALIAS_DEF)arg->internal.aliases;
    (ALIAS_DEF)arg->internal.aliases = a;
#endif
}

/****************
 * Get options from a file.
 * Lines starting with '#' are comment lines.
 * Syntax is simply a keyword and the argument.
 * Valid keywords are all keywords from the long_opt list without
 * the leading dashes. The special keywords "help", "warranty" and "version"
 * are not valid here.
 * The special keyword "alias" may be used to store alias definitions,
 * which are later expanded like long options.
 * Caller must free returned strings.
 * If called with FP set to NULL command line args are parse instead.
 *
 * Q: Should we allow the syntax
 *     keyword = value
 *    and accept for boolean options a value of 1/0, yes/no or true/false?
 * Note: Abbreviation of options is here not allowed.
 */
int
optfile_parse( FILE *fp, const char *filename, unsigned *lineno,
               ARGPARSE_ARGS *arg, ARGPARSE_OPTS *opts)
{
    int state, i, c;
    int idx=0;
    char keyword[100];
    char *buffer = NULL;
    size_t buflen = 0;
    int inverse=0;
    int in_alias=0;

    if( !fp ) /* same as arg_parse() in this case */
        return arg_parse( arg, opts );

    initialize( arg, filename, lineno );

    /* find the next keyword */
    state = i = 0;
    for(;;) {
        c=getc(fp);
        if( c == '\n' || c== EOF ) {
            if( c != EOF )
                ++*lineno;
            if( state == -1 )
                break;
            else if( state == 2 ) {
                keyword[i] = 0;
                for(i=0; opts[i].short_opt; i++ )
                    if( opts[i].long_opt && !strcmp( opts[i].long_opt, keyword) )
                        break;
                idx = i;
                arg->r_opt = opts[idx].short_opt;
                if( inverse ) /* this does not have an effect, hmmm */
                    arg->r_opt = -arg->r_opt;
                if( !opts[idx].short_opt )   /* unknown command/option */
                    arg->r_opt = (opts[idx].flags & 256)? -7:-2;
                else if( !(opts[idx].flags & 7) ) /* does not take an arg */
                    arg->r_type = 0;           /* okay */
                else if( (opts[idx].flags & 8) )  /* argument is optional */
                    arg->r_type = 0;           /* okay */
                else                           /* required argument */
                    arg->r_opt = -3;           /* error */
                break;
            }
            else if( state == 3 ) {            /* no argument found */
                if( in_alias )
                    arg->r_opt = -3;           /* error */
                else if( !(opts[idx].flags & 7) ) /* does not take an arg */
                    arg->r_type = 0;           /* okay */
                else if( (opts[idx].flags & 8) )  /* no optional argument */
                    arg->r_type = 0;           /* okay */
                else                           /* no required argument */
                    arg->r_opt = -3;           /* error */
                break;
            }
            else if( state == 4 ) {     /* have an argument */
                if( in_alias ) {
                    if( !buffer )
                        arg->r_opt = -6;
                    else {
                        char *p;

                        buffer[i] = 0;
                        p = strpbrk( buffer, " \t" );
                        if( p ) {
                            *p++ = 0;
                            trim_spaces( p );
                        }
                        if( !p || !*p ) {
                            jnlib_free( buffer );
                            arg->r_opt = -10;
                        }
                        else {
                            store_alias( arg, buffer, p );
                        }
                    }
                }
                else if( !(opts[idx].flags & 7) )  /* does not take an arg */
                    arg->r_opt = -6;        /* error */
                else {
                    char *p;
                    if( !buffer ) {
                        keyword[i] = 0;
                        buffer = jnlib_xstrdup(keyword);
                    }
                    else
                        buffer[i] = 0;

                    trim_spaces( buffer );
                    p = buffer;
                    if( *p == '"' ) { /* remove quotes */
                        p++;
                        if( *p && p[strlen(p)-1] == '"' )
                            p[strlen(p)-1] = 0;
                    }
                    if( !set_opt_arg(arg, opts[idx].flags, p) )
                        jnlib_free(buffer);
                }
                break;
            }
            else if( c == EOF ) {
                if( ferror(fp) )
                    arg->r_opt = -5;   /* read error */
                else
                    arg->r_opt = 0;    /* eof */
                break;
            }
            state = 0;
            i = 0;
        }
        else if( state == -1 )
            ; /* skip */
        else if( !state && isspace(c) )
            ; /* skip leading white space */
        else if( !state && c == '#' )
            state = 1;  /* start of a comment */
        else if( state == 1 )
            ; /* skip comments */
        else if( state == 2 && isspace(c) ) {
            keyword[i] = 0;
            for(i=0; opts[i].short_opt; i++ )
                if( opts[i].long_opt && !strcmp( opts[i].long_opt, keyword) )
                    break;
            idx = i;
            arg->r_opt = opts[idx].short_opt;
            if( !opts[idx].short_opt ) {
                if( !strcmp( keyword, "alias" ) ) {
                    in_alias = 1;
                    state = 3;
                }
                else {
                    arg->r_opt = (opts[idx].flags & 256)? -7:-2;
                    state = -1;        /* skip rest of line and leave */
                }
            }
            else
                state = 3;
        }
        else if( state == 3 ) { /* skip leading spaces of the argument */
            if( !isspace(c) ) {
                i = 0;
                keyword[i++] = c;
                state = 4;
            }
        }
        else if( state == 4 ) { /* collect the argument */
            if( buffer ) {
                if( i < buflen-1 )
                    buffer[i++] = c;
                else {
                    buflen += 50;
                    buffer = jnlib_xrealloc(buffer, buflen);
                    buffer[i++] = c;
                }
            }
            else if( i < DIM(keyword)-1 )
                keyword[i++] = c;
            else {
                buflen = DIM(keyword)+50;
                buffer = jnlib_xmalloc(buflen);
                memcpy(buffer, keyword, i);
                buffer[i++] = c;
            }
        }
        else if( i >= DIM(keyword)-1 ) {
            arg->r_opt = -4;   /* keyword to long */
            state = -1;        /* skip rest of line and leave */
        }
        else {
            keyword[i++] = c;
            state = 2;
        }
    }

    return arg->r_opt;
}



static int
find_long_option( ARGPARSE_ARGS *arg,
                  ARGPARSE_OPTS *opts, const char *keyword )
{
    int i;
    size_t n;

    /* Would be better if we can do a binary search, but it is not
       possible to reorder our option table because we would mess
       up our help strings - What we can do is: Build a nice option
       lookup table wehn this function is first invoked */
    if( !*keyword )
        return -1;
    for(i=0; opts[i].short_opt; i++ )
        if( opts[i].long_opt && !strcmp( opts[i].long_opt, keyword) )
            return i;
  #if 0
    {
        ALIAS_DEF a;
        /* see whether it is an alias */
        for( a = args->internal.aliases; a; a = a->next ) {
            if( !strcmp( a->name, keyword) ) {
                /* todo: must parse the alias here */
                args->internal.cur_alias = a;
                return -3; /* alias available */
            }
        }
    }
  #endif
    /* not found, see whether it is an abbreviation */
    /* aliases may not be abbreviated */
    n = strlen( keyword );
    for(i=0; opts[i].short_opt; i++ ) {
        if( opts[i].long_opt && !strncmp( opts[i].long_opt, keyword, n ) ) {
            int j;
            for(j=i+1; opts[j].short_opt; j++ ) {
                if( opts[j].long_opt
                    && !strncmp( opts[j].long_opt, keyword, n ) )
                    return -2;  /* abbreviation is ambiguous */
            }
            return i;
        }
    }
    return -1;
}

int
arg_parse( ARGPARSE_ARGS *arg, ARGPARSE_OPTS *opts)
{
    int idx;
    int argc;
    char **argv;
    char *s, *s2;
    int i;

    initialize( arg, NULL, NULL );
    argc = *arg->argc;
    argv = *arg->argv;
    idx = arg->internal.idx;

    if( !idx && argc && !(arg->flags & (1<<4)) ) { /* skip the first entry */
        argc--; argv++; idx++;
    }

  next_one:
    if( !argc ) { /* no more args */
        arg->r_opt = 0;
        goto leave; /* ready */
    }

    s = *argv;
    arg->internal.last = s;

    if( arg->internal.stopped && (arg->flags & (1<<1)) ) {
        arg->r_opt = -1;  /* not an option but a argument */
        arg->r_type = 2;
        arg->r.ret_str = s;
        argc--; argv++; idx++; /* set to next one */
    }
    else if( arg->internal.stopped ) { /* ready */
        arg->r_opt = 0;
        goto leave;
    }
    else if( *s == '-' && s[1] == '-' ) { /* long option */
        char *argpos;

        arg->internal.inarg = 0;
        if( !s[2] && !(arg->flags & (1<<3)) ) { /* stop option processing */
            arg->internal.stopped = 1;
            argc--; argv++; idx++;
            goto next_one;
        }

        argpos = strchr( s+2, '=' );
        if( argpos )
            *argpos = 0;
        i = find_long_option( arg, opts, s+2 );
        if( argpos )
            *argpos = '=';

        if( i < 0 && !strcmp( "help", s+2) )
            show_help(opts, arg->flags);
        else if( i < 0 && !strcmp( "version", s+2) ) {
            if( !(arg->flags & (1<<6)) ) {
                show_version();
                exit(0);
            }
        }
        else if( i < 0 && !strcmp( "warranty", s+2) ) {
            puts( strusage(16) );
            exit(0);
        }
        else if( i < 0 && !strcmp( "dump-options", s+2) ) {
            for(i=0; opts[i].short_opt; i++ ) {
                if( opts[i].long_opt )
                    printf( "--%s\n", opts[i].long_opt );
            }
            fputs("--dump-options\n--help\n--version\n--warranty\n", stdout );
            exit(0);
        }

        if( i == -2 ) /* ambiguous option */
            arg->r_opt = -8;
        else if( i == -1 ) {
            arg->r_opt = -2;
            arg->r.ret_str = s+2;
        }
        else
            arg->r_opt = opts[i].short_opt;
        if( i < 0 )
            ;
        else if( (opts[i].flags & 7) ) {
            if( argpos ) {
                s2 = argpos+1;
                if( !*s2 )
                    s2 = NULL;
            }
            else
                s2 = argv[1];
            if( !s2 && (opts[i].flags & 8) ) { /* no argument but it is okay*/
                arg->r_type = 0;               /* because it is optional */
            }
            else if( !s2 ) {
                arg->r_opt = -3; /* missing argument */
            }
            else if( !argpos && *s2 == '-' && (opts[i].flags & 8) ) {
                /* the argument is optional and the next seems to be
                 * an option. We do not check this possible option
                 * but assume no argument */
                arg->r_type = 0;
            }
            else {
                set_opt_arg(arg, opts[i].flags, s2);
                if( !argpos ) {
                    argc--; argv++; idx++; /* skip one */
                }
            }
        }
        else { /* does not take an argument */
            if( argpos )
                arg->r_type = -6; /* argument not expected */
            else
                arg->r_type = 0;
        }
        argc--; argv++; idx++; /* set to next one */
    }
    else if( (*s == '-' && s[1]) || arg->internal.inarg ) { /* short option */
        int dash_kludge = 0;
        i = 0;
        if( !arg->internal.inarg ) {
            arg->internal.inarg++;
            if( arg->flags & (1<<5) ) {
                for(i=0; opts[i].short_opt; i++ )
                    if( opts[i].long_opt && !strcmp( opts[i].long_opt, s+1)) {
                        dash_kludge=1;
                        break;
                    }
            }
        }
        s += arg->internal.inarg;

        if( !dash_kludge ) {
            for(i=0; opts[i].short_opt; i++ )
                if( opts[i].short_opt == *s )
                    break;
        }

        if( !opts[i].short_opt && ( *s == 'h' || *s == '?' ) )
            show_help(opts, arg->flags);

        arg->r_opt = opts[i].short_opt;
        if( !opts[i].short_opt ) {
            arg->r_opt = (opts[i].flags & 256)? -7:-2;
            arg->internal.inarg++; /* point to the next arg */
            arg->r.ret_str = s;
        }
        else if( (opts[i].flags & 7) ) {
            if( s[1] && !dash_kludge ) {
                s2 = s+1;
                set_opt_arg(arg, opts[i].flags, s2);
            }
            else {
                s2 = argv[1];
                if( !s2 && (opts[i].flags & 8) ) { /* no argument but it is okay*/
                    arg->r_type = 0;               /* because it is optional */
                }
                else if( !s2 ) {
                    arg->r_opt = -3; /* missing argument */
                }
                else if( *s2 == '-' && s2[1] && (opts[i].flags & 8) ) {
                    /* the argument is optional and the next seems to be
                     * an option. We do not check this possible option
                     * but assume no argument */
                    arg->r_type = 0;
                }
                else {
                    set_opt_arg(arg, opts[i].flags, s2);
                    argc--; argv++; idx++; /* skip one */
                }
            }
            s = "x"; /* so that !s[1] yields false */
        }
        else { /* does not take an argument */
            arg->r_type = 0;
            arg->internal.inarg++; /* point to the next arg */
        }
        if( !s[1] || dash_kludge ) { /* no more concatenated short options */
            arg->internal.inarg = 0;
            argc--; argv++; idx++;
        }
    }
    else if( arg->flags & (1<<2) ) {
        arg->r_opt = -1;  /* not an option but a argument */
        arg->r_type = 2;
        arg->r.ret_str = s;
        argc--; argv++; idx++; /* set to next one */
    }
    else {
        arg->internal.stopped = 1; /* stop option processing */
        goto next_one;
    }

  leave:
    *arg->argc = argc;
    *arg->argv = argv;
    arg->internal.idx = idx;
    return arg->r_opt;
}



static int
set_opt_arg(ARGPARSE_ARGS *arg, unsigned flags, char *s)
{
    int base = (flags & 16)? 0 : 10;

    switch( arg->r_type = (flags & 7) ) {
      case 1: /* takes int argument */
        arg->r.ret_int = (int)strtol(s,NULL,base);
        return 0;
      case 3: /* takes long argument   */
        arg->r.ret_long= strtol(s,NULL,base);
        return 0;
      case 4: /* takes ulong argument  */
        arg->r.ret_ulong= strtoul(s,NULL,base);
        return 0;
      case 2: /* takes string argument */
      default:
        arg->r.ret_str = s;
        return 1;
    }
}


static size_t
long_opt_strlen( ARGPARSE_OPTS *o )
{
    size_t n = strlen(o->long_opt);

    if( o->description && *o->description == '|' ) {
        const char *s;

        s=o->description+1;
        if( *s != '=' )
            n++;
        for(; *s && *s != '|'; s++ )
            n++;
    }
    return n;
}

/****************
 * Print formatted help. The description string has some special
 * meanings:
 *  - A description string which is "@" suppresses help output for
 *    this option
 *  - a description,ine which starts with a '@' and is followed by
 *    any other characters is printed as is; this may be used for examples
 *    ans such.
 *  - A description which starts with a '|' outputs the string between this
 *    bar and the next one as arguments of the long option.
 */
static void
show_help( ARGPARSE_OPTS *opts, unsigned flags )
{
    const char *s;

    show_version();
    putchar('\n');
    s = strusage(41);
    puts(s);
    if( opts[0].description ) { /* auto format the option description */
        int i,j, indent;
        /* get max. length of long options */
        for(i=indent=0; opts[i].short_opt; i++ ) {
            if( opts[i].long_opt )
                if( !opts[i].description || *opts[i].description != '@' )
                    if( (j=long_opt_strlen(opts+i)) > indent && j < 35 )
                         indent = j;
        }
        /* example: " -v, --verbose   Viele Sachen ausgeben" */
        indent += 10;
        if( *opts[0].description != '@' )
            puts("Options:");
        for(i=0; opts[i].short_opt; i++ ) {
            s = _( opts[i].description );
            if( s && *s== '@' && !s[1] ) /* hide this line */
                continue;
            if( s && *s == '@' ) { /* unindented comment only line */
                for(s++; *s; s++ ) {
                    if( *s == '\n' ) {
                        if( s[1] )
                            putchar('\n');
                    }
                    else
                        putchar(*s);
                }
                putchar('\n');
                continue;
            }

            j = 3;
            if( opts[i].short_opt < 256 ) {
                printf(" -%c", opts[i].short_opt );
                if( !opts[i].long_opt ) {
                    if(s && *s == '|' ) {
                        putchar(' '); j++;
                        for(s++ ; *s && *s != '|'; s++, j++ )
                            putchar(*s);
                        if( *s )
                            s++;
                    }
                }
            }
            else
                fputs("   ", stdout);
            if( opts[i].long_opt ) {
                j += printf("%c --%s", opts[i].short_opt < 256?',':' ',
                                       opts[i].long_opt );
                if(s && *s == '|' ) {
                    if( *++s != '=' ) {
                        putchar(' ');
                        j++;
                    }
                    for( ; *s && *s != '|'; s++, j++ )
                        putchar(*s);
                    if( *s )
                        s++;
                }
                fputs("   ", stdout);
                j += 3;
            }
            for(;j < indent; j++ )
                putchar(' ');
            if( s ) {
                if( *s && j > indent ) {
                    putchar('\n');
                    for(j=0;j < indent; j++ )
                        putchar(' ');
                }
                for(; *s; s++ ) {
                    if( *s == '\n' ) {
                        if( s[1] ) {
                            putchar('\n');
                            for(j=0;j < indent; j++ )
                                putchar(' ');
                        }
                    }
                    else
                        putchar(*s);
                }
            }
            putchar('\n');
        }
        if( flags & 32 )
            puts("\n(A single dash may be used instead of the double ones)");
    }
    if( (s=strusage(19)) ) {  /* bug reports to ... */
        putchar('\n');
        fputs(s, stdout);
    }
    fflush(stdout);
    exit(0);
}

static void
show_version()
{
    const char *s;
    int i;
    /* version line */
    fputs(strusage(11), stdout);
    if( (s=strusage(12)) )
        printf(" (%s)", s );
    printf(" %s\n", strusage(13) );
    /* additional version lines */
    for(i=20; i < 30; i++ )
        if( (s=strusage(i)) )
            printf("%s\n", s );
    /* copyright string */
    if( (s=strusage(14)) )
        printf("%s\n", s );
    /* copying conditions */
    if( (s=strusage(15)) )
        fputs(s, stdout);
    /* thanks */
    if( (s=strusage(18)) )
        fputs(s, stdout);
    /* additional program info */
    for(i=30; i < 40; i++ )
        if( (s=strusage(i)) )
            fputs (s, stdout);
    fflush(stdout);
}


void
usage( int level )
{
    if( !level ) {
        fprintf(stderr,"%s %s; %s\n", strusage(11), strusage(13),
                                                     strusage(14) );
        fflush(stderr);
    }
    else if( level == 1 ) {
        fputs(strusage(40),stderr);
        exit(2);
    }
    else if( level == 2 ) {
        puts(strusage(41));
        exit(0);
    }
}

/* Level
 *     0: Copyright String auf stderr ausgeben
 *     1: Kurzusage auf stderr ausgeben und beenden
 *     2: Langusage auf stdout ausgeben und beenden
 *    11: name of program
 *    12: optional name of package which includes this program.
 *    13: version  string
 *    14: copyright string
 *    15: Short copying conditions (with LFs)
 *    16: Long copying conditions (with LFs)
 *    17: Optional printable OS name
 *    18: Optional thanks list   (with LFs)
 *    19: Bug report info
 *20..29: Additional lib version strings.
 *30..39: Additional program info (with LFs)
 *    40: short usage note (with LF)
 *    41: long usage note (with LF)
 */
const char *
strusage( int level )
{
    const char *p = strusage_handler? strusage_handler(level) : NULL;

    if( p )
        return p;

    switch( level ) {
      case 11: p = "foo"; break;
      case 13: p = "0.0"; break;
      case 14: p = "Copyright (C) 2006 Free Software Foundation, Inc."; break;
      case 15: p =
"This program comes with ABSOLUTELY NO WARRANTY.\n"
"This is free software, and you are welcome to redistribute it\n"
"under certain conditions. See the file COPYING for details.\n"; break;
      case 16:  p =
"This is free software; you can redistribute it and/or modify\n"
"it under the terms of the GNU General Public License as published by\n"
"the Free Software Foundation; either version 2 of the License, or\n"
"(at your option) any later version.\n\n"
"It is distributed in the hope that it will be useful,\n"
"but WITHOUT ANY WARRANTY; without even the implied warranty of\n"
"MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n"
"GNU General Public License for more details.\n\n"
"You should have received a copy of the GNU General Public License\n"
"along with this program; if not, write to the Free Software\n"
"Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,\n"
"USA.\n";
        break;
      case 40: /* short and long usage */
      case 41: p = ""; break;
    }

    return p;
}

void
set_strusage( const char *(*f)( int ) )
{
    strusage_handler = f;
}


#ifdef TEST
static struct {
    int verbose;
    int debug;
    char *outfile;
    char *crf;
    int myopt;
    int echo;
    int a_long_one;
}opt;

int
main(int argc, char **argv)
{
    ARGPARSE_OPTS opts[] = {
    { 'v', "verbose",   0 , "Laut sein"},
    { 'e', "echo"   ,   0 , "Zeile ausgeben, damit wir sehen, was wir einegegeben haben"},
    { 'd', "debug",     0 , "Debug\nfalls mal etasws\nSchief geht"},
    { 'o', "output",    2   },
    { 'c', "cross-ref", 2|8, "cross-reference erzeugen\n" },
    { 'm', "my-option", 1|8 },
    { 500, "a-long-option", 0 },
    {0} };
    ARGPARSE_ARGS pargs = { &argc, &argv, 2|4|32 };
    int i;

    while( ArgParse( &pargs, opts) ) {
        switch( pargs.r_opt ) {
          case -1 : printf( "arg=`%s'\n", pargs.r.ret_str); break;
          case 'v': opt.verbose++; break;
          case 'e': opt.echo++; break;
          case 'd': opt.debug++; break;
          case 'o': opt.outfile = pargs.r.ret_str; break;
          case 'c': opt.crf = pargs.r_type? pargs.r.ret_str:"a.crf"; break;
          case 'm': opt.myopt = pargs.r_type? pargs.r.ret_int : 1; break;
          case 500: opt.a_long_one++;  break;
          default : pargs.err = 1; break; /* force warning output */
        }
    }
    for(i=0; i < argc; i++ )
        printf("%3d -> (%s)\n", i, argv[i] );
    puts("Options:");
    if( opt.verbose )
        printf("  verbose=%d\n", opt.verbose );
    if( opt.debug )
        printf("  debug=%d\n", opt.debug );
    if( opt.outfile )
        printf("  outfile=`%s'\n", opt.outfile );
    if( opt.crf )
        printf("  crffile=`%s'\n", opt.crf );
    if( opt.myopt )
        printf("  myopt=%d\n", opt.myopt );
    if( opt.a_long_one )
        printf("  a-long-one=%d\n", opt.a_long_one );
    if( opt.echo       )
        printf("  echo=%d\n", opt.echo );
    return 0;
}
#endif

/**** bottom of file ****/