release/src/router/transmission/libtransmission/tr-getopt.c

   1 /*
   2  * This file Copyright (C) 2008-2010 Mnemosyne LLC
   3  *
   4  * This file is licensed by the GPL version 2.  Works owned by the
   5  * Transmission project are granted a special exemption to clause 2(b)
   6  * so that the bulk of its code can remain under the MIT license.
   7  * This exemption does not extend to derived works not owned by
   8  * the Transmission project.
   9  *
  10  * $Id: tr-getopt.c 10782 2010-06-16 14:05:18Z charles $
  11  */
  12
  13 #include <ctype.h> /* isspace() */
  14 #include <stdio.h>
  15 #include <stdlib.h> /* exit() */
  16 #include <string.h>
  17
  18 #include "tr-getopt.h"
  19
  20 #ifndef MAX
  21  #define MAX( a, b ) ( ( ( a ) > ( b ) ) ? ( a ) : ( b ) )
  22 #endif
  23
  24 int tr_optind = 1;
  25
  26 static const char*
  27 getArgName( const tr_option * opt )
  28 {
  29     const char * arg;
  30
  31     if( !opt->has_arg )
  32         arg = "";
  33     else if( opt->argName )
  34         arg = opt->argName;
  35     else
  36         arg = "<args>";
  37
  38     return arg;
  39 }
  40
  41 static int
  42 get_next_line_len( const char * description, int maxlen )
  43 {
  44     int end;
  45     int len = strlen( description );
  46
  47     if( len < maxlen )
  48         return len;
  49
  50     end = maxlen < len ? maxlen : len;
  51     while( ( end > 0 ) && !isspace( description[end] ) )
  52         --end;
  53
  54     return end ? end : len;
  55 }
  56
  57 static void
  58 getopts_usage_line( const tr_option * opt,
  59                     int               longWidth,
  60                     int               shortWidth,
  61                     int               argWidth )
  62 {
  63     int len;
  64     const char * longName   = opt->longName ? opt->longName : "";
  65     const char * shortName  = opt->shortName ? opt->shortName : "";
  66     const char * arg        = getArgName( opt );
  67
  68     const int d_indent = shortWidth + longWidth + argWidth + 7;
  69     const int d_width = 80 - d_indent;
  70     const char * d = opt->description;
  71
  72     printf( " %s%-*s %s%-*s %-*s ",
  73             (shortName && *shortName ? "-" : " "), shortWidth, shortName,
  74             (longName && *longName ? "--" : "  "), longWidth, longName,
  75             argWidth, arg );
  76     len = get_next_line_len( d, d_width );
  77     printf( "%*.*s\n", len, len, d );
  78
  79     d += len;
  80     while( isspace( *d ) ) ++d;
  81
  82     while(( len = get_next_line_len( d, d_width ))) {
  83         printf( "%*.*s%*.*s\n", d_indent, d_indent, "", len, len, d );
  84         d += len;
  85         while( isspace( *d ) ) ++d;
  86     }
  87 }
  88
  89 static void
  90 maxWidth( const struct tr_option * o,
  91           int *                    longWidth,
  92           int *                    shortWidth,
  93           int *                    argWidth )
  94 {
  95     const char * arg;
  96
  97     if( o->longName )
  98         *longWidth = MAX( *longWidth, (int)strlen( o->longName ) );
  99
 100     if( o->shortName )
 101         *shortWidth = MAX( *shortWidth, (int)strlen( o->shortName ) );
 102
 103     if( ( arg = getArgName( o ) ) )
 104         *argWidth = MAX( *argWidth, (int)strlen( arg ) );
 105 }
 106
 107 void
 108 tr_getopt_usage( const char *           progName,
 109                  const char *           description,
 110                  const struct tr_option opts[] )
 111 {
 112     int                      longWidth = 0;
 113     int                      shortWidth = 0;
 114     int                      argWidth = 0;
 115     struct tr_option         help;
 116     const struct tr_option * o;
 117
 118     for( o = opts; o->val; ++o )
 119         maxWidth( o, &longWidth, &shortWidth, &argWidth );
 120
 121     help.val = -1;
 122     help.longName = "help";
 123     help.description = "Display this help page and exit";
 124     help.shortName = "h";
 125     help.has_arg = 0;
 126     maxWidth( &help, &longWidth, &shortWidth, &argWidth );
 127
 128     if( description == NULL )
 129         description = "Usage: %s [options]";
 130     printf( description, progName );
 131     printf( "\n\nOptions:\n" );
 132     getopts_usage_line( &help, longWidth, shortWidth, argWidth );
 133     for( o = opts; o->val; ++o )
 134         getopts_usage_line( o, longWidth, shortWidth, argWidth );
 135 }
 136
 137 static const tr_option *
 138 findOption( const tr_option * opts,
 139             const char *      str,
 140             const char **     setme_arg )
 141 {
 142     size_t            matchlen = 0;
 143     const char *      arg = NULL;
 144     const tr_option * o;
 145     const tr_option * match = NULL;
 146
 147     /* find the longest matching option */
 148     for( o = opts; o->val; ++o )
 149     {
 150         size_t len = o->longName ? strlen( o->longName ) : 0;
 151
 152         if( ( matchlen < len ) && !memcmp( str, "--", 2 )
 153           && !memcmp( str + 2, o->longName, len )
 154           && ( str[len + 2] == '\0' || ( o->has_arg && str[len + 2] == '=' ) ) )
 155         {
 156             matchlen = len;
 157             match = o;
 158             arg = str[len + 2] == '=' ? str + len + 3 : NULL;
 159         }
 160
 161         len = o->shortName ? strlen( o->shortName ) : 0;
 162
 163         if( ( matchlen < len ) && !memcmp( str, "-", 1 )
 164           && !memcmp( str + 1, o->shortName, len )
 165           && ( str[len + 1] == '\0' || o->has_arg ) )
 166         {
 167             matchlen = len;
 168             match = o;
 169             switch( str[len + 1] )
 170             {
 171                 case '\0':
 172                     arg = NULL;          break;
 173
 174                 case '=':
 175                     arg = str + len + 2; break;
 176
 177                 default:
 178                     arg = str + len + 1; break;
 179             }
 180         }
 181     }
 182
 183     if( setme_arg )
 184         *setme_arg = arg;
 185
 186     return match;
 187 }
 188
 189 int
 190 tr_getopt( const char *      usage,
 191            int               argc,
 192            const char **     argv,
 193            const tr_option * opts,
 194            const char **     setme_optarg )
 195 {
 196     int               i;
 197     const char *      arg = NULL;
 198     const tr_option * o = NULL;
 199
 200     *setme_optarg = NULL;
 201
 202     /* handle the builtin 'help' option */
 203     for( i = 1; i < argc; ++i )
 204     {
 205         if( !strcmp( argv[i], "-h" ) || !strcmp( argv[i], "--help" ) )
 206         {
 207             tr_getopt_usage( argv[0], usage, opts );
 208             exit( 0 );
 209         }
 210     }
 211
 212     /* out of options? */
 213     if( argc == 1 || tr_optind >= argc )
 214         return TR_OPT_DONE;
 215
 216     o = findOption( opts, argv[tr_optind], &arg );
 217     if( !o )
 218     {
 219         /* let the user know we got an unknown option... */
 220         *setme_optarg = argv[tr_optind++];
 221         return TR_OPT_UNK;
 222     }
 223
 224     if( !o->has_arg )
 225     {
 226         /* no argument needed for this option, so we're done */
 227         if( arg )
 228             return TR_OPT_ERR;
 229         *setme_optarg = NULL;
 230         ++tr_optind;
 231         return o->val;
 232     }
 233
 234     /* option needed an argument, and it was embedded in this string */
 235     if( arg )
 236     {
 237         *setme_optarg = arg;
 238         ++tr_optind;
 239         return o->val;
 240     }
 241
 242     /* throw an error if the option needed an argument but didn't get one */
 243     if( ++tr_optind >= argc )
 244         return TR_OPT_ERR;
 245     if( findOption( opts, argv[tr_optind], NULL ) )
 246         return TR_OPT_ERR;
 247
 248     *setme_optarg = argv[tr_optind++];
 249     return o->val;
 250 }