help.c

   1 /*
   2  * This program is free software; you can redistribute it and/or
   3  * modify it under the terms of the GNU General Public
   4  * License v2 as published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   9  * General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public
  12  * License along with this program; if not, write to the
  13  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  14  * Boston, MA 021110-1307, USA.
  15  */
  16
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20
  21 #include "commands.h"
  22 #include "utils.h"
  23
  24 static char argv0_buf[ARGV0_BUF_SIZE];
  25
  26 #define USAGE_SHORT             1U
  27 #define USAGE_LONG              2U
  28 #define USAGE_OPTIONS           4U
  29 #define USAGE_LISTING           8U
  30
  31 static int do_usage_one_command(const char * const *usagestr,
  32                                 unsigned int flags, FILE *outf)
  33 {
  34         int pad = 4;
  35
  36         if (!usagestr || !*usagestr)
  37                 return -1;
  38
  39         fprintf(outf, "%s%s\n", (flags & USAGE_LISTING) ? "    " : "usage: ",
  40                 *usagestr++);
  41
  42         /* a short one-line description (mandatory) */
  43         if ((flags & USAGE_SHORT) == 0)
  44                 return 0;
  45         else if (!*usagestr)
  46                 return -2;
  47
  48         if (flags & USAGE_LISTING)
  49                 pad = 8;
  50         else
  51                 fputc('\n', outf);
  52
  53         fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
  54
  55         /* a long (possibly multi-line) description (optional) */
  56         if (!*usagestr || ((flags & USAGE_LONG) == 0))
  57                 return 0;
  58
  59         if (**usagestr)
  60                 fputc('\n', outf);
  61         while (*usagestr && **usagestr)
  62                 fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
  63
  64         /* options (optional) */
  65         if (!*usagestr || ((flags & USAGE_OPTIONS) == 0))
  66                 return 0;
  67
  68         /*
  69          * options (if present) should always (even if there is no long
  70          * description) be prepended with an empty line, skip it
  71          */
  72         usagestr++;
  73
  74         fputc('\n', outf);
  75         while (*usagestr)
  76                 fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
  77
  78         return 0;
  79 }
  80
  81 static int usage_command_internal(const char * const *usagestr,
  82                                   const char *token, int full, int lst,
  83                                   FILE *outf)
  84 {
  85         unsigned int flags = USAGE_SHORT;
  86         int ret;
  87
  88         if (full)
  89                 flags |= USAGE_LONG | USAGE_OPTIONS;
  90         if (lst)
  91                 flags |= USAGE_LISTING;
  92
  93         ret = do_usage_one_command(usagestr, flags, outf);
  94         switch (ret) {
  95         case -1:
  96                 fprintf(outf, "No usage for '%s'\n", token);
  97                 break;
  98         case -2:
  99                 fprintf(outf, "No short description for '%s'\n", token);
 100                 break;
 101         }
 102
 103         return ret;
 104 }
 105
 106 static void usage_command_usagestr(const char * const *usagestr,
 107                                    const char *token, int full, int err)
 108 {
 109         FILE *outf = err ? stderr : stdout;
 110         int ret;
 111
 112         ret = usage_command_internal(usagestr, token, full, 0, outf);
 113         if (!ret)
 114                 fputc('\n', outf);
 115 }
 116
 117 void usage_command(const struct cmd_struct *cmd, int full, int err)
 118 {
 119         usage_command_usagestr(cmd->usagestr, cmd->token, full, err);
 120 }
 121
 122 void usage(const char * const *usagestr)
 123 {
 124         usage_command_usagestr(usagestr, NULL, 1, 1);
 125         exit(1);
 126 }
 127
 128 static void usage_command_group_internal(const struct cmd_group *grp, int full,
 129                                          FILE *outf)
 130 {
 131         const struct cmd_struct *cmd = grp->commands;
 132         int do_sep = 0;
 133
 134         for (; cmd->token; cmd++) {
 135                 if (cmd->hidden)
 136                         continue;
 137
 138                 if (full && cmd != grp->commands)
 139                         fputc('\n', outf);
 140
 141                 if (!cmd->next) {
 142                         if (do_sep) {
 143                                 fputc('\n', outf);
 144                                 do_sep = 0;
 145                         }
 146
 147                         usage_command_internal(cmd->usagestr, cmd->token, full,
 148                                                1, outf);
 149                         continue;
 150                 }
 151
 152                 /* this is an entry point to a nested command group */
 153
 154                 if (!full && cmd != grp->commands)
 155                         fputc('\n', outf);
 156
 157                 usage_command_group_internal(cmd->next, full, outf);
 158
 159                 if (!full)
 160                         do_sep = 1;
 161         }
 162 }
 163
 164 void usage_command_group(const struct cmd_group *grp, int full, int err)
 165 {
 166         const char * const *usagestr = grp->usagestr;
 167         FILE *outf = err ? stderr : stdout;
 168
 169         if (usagestr && *usagestr) {
 170                 fprintf(outf, "usage: %s\n", *usagestr++);
 171                 while (*usagestr)
 172                         fprintf(outf, "   or: %s\n", *usagestr++);
 173         }
 174
 175         fputc('\n', outf);
 176         usage_command_group_internal(grp, full, outf);
 177         fputc('\n', outf);
 178
 179         if (grp->infostr)
 180                 fprintf(outf, "%s\n", grp->infostr);
 181 }
 182
 183 void help_unknown_token(const char *arg, const struct cmd_group *grp)
 184 {
 185         fprintf(stderr, "%s: unknown token '%s'\n", argv0_buf, arg);
 186         usage_command_group(grp, 0, 1);
 187         exit(1);
 188 }
 189
 190 void help_ambiguous_token(const char *arg, const struct cmd_group *grp)
 191 {
 192         const struct cmd_struct *cmd = grp->commands;
 193
 194         fprintf(stderr, "%s: ambiguous token '%s'\n", argv0_buf, arg);
 195         fprintf(stderr, "\nDid you mean one of these ?\n");
 196
 197         for (; cmd->token; cmd++) {
 198                 if (!prefixcmp(cmd->token, arg))
 199                         fprintf(stderr, "\t%s\n", cmd->token);
 200         }
 201
 202         exit(1);
 203 }
 204
 205 void help_command_group(const struct cmd_group *grp, int argc, char **argv)
 206 {
 207         int full = 0;
 208
 209         if (argc > 1) {
 210                 if (!strcmp(argv[1], "--full"))
 211                         full = 1;
 212         }
 213
 214         usage_command_group(grp, full, 0);
 215 }