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 #include <limits.h>
  21
  22 #include "commands.h"
  23 #include "utils.h"
  24
  25 static char argv0_buf[ARGV0_BUF_SIZE];
  26
  27 #define USAGE_SHORT             1U
  28 #define USAGE_LONG              2U
  29 #define USAGE_OPTIONS           4U
  30 #define USAGE_LISTING           8U
  31
  32 static int do_usage_one_command(const char * const *usagestr,
  33                                 unsigned int flags, FILE *outf)
  34 {
  35         int pad = 4;
  36
  37         if (!usagestr || !*usagestr)
  38                 return -1;
  39
  40         fprintf(outf, "%s%s\n", (flags & USAGE_LISTING) ? "    " : "usage: ",
  41                 *usagestr++);
  42
  43         /* a short one-line description (mandatory) */
  44         if ((flags & USAGE_SHORT) == 0)
  45                 return 0;
  46         else if (!*usagestr)
  47                 return -2;
  48
  49         if (flags & USAGE_LISTING)
  50                 pad = 8;
  51         else
  52                 fputc('\n', outf);
  53
  54         fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
  55
  56         /* a long (possibly multi-line) description (optional) */
  57         if (!*usagestr || ((flags & USAGE_LONG) == 0))
  58                 return 0;
  59
  60         if (**usagestr)
  61                 fputc('\n', outf);
  62         while (*usagestr && **usagestr)
  63                 fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
  64
  65         /* options (optional) */
  66         if (!*usagestr || ((flags & USAGE_OPTIONS) == 0))
  67                 return 0;
  68
  69         /*
  70          * options (if present) should always (even if there is no long
  71          * description) be prepended with an empty line, skip it
  72          */
  73         usagestr++;
  74
  75         fputc('\n', outf);
  76         while (*usagestr)
  77                 fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
  78
  79         return 0;
  80 }
  81
  82 static int usage_command_internal(const char * const *usagestr,
  83                                   const char *token, int full, int lst,
  84                                   FILE *outf)
  85 {
  86         unsigned int flags = USAGE_SHORT;
  87         int ret;
  88
  89         if (full)
  90                 flags |= USAGE_LONG | USAGE_OPTIONS;
  91         if (lst)
  92                 flags |= USAGE_LISTING;
  93
  94         ret = do_usage_one_command(usagestr, flags, outf);
  95         switch (ret) {
  96         case -1:
  97                 fprintf(outf, "No usage for '%s'\n", token);
  98                 break;
  99         case -2:
 100                 fprintf(outf, "No short description for '%s'\n", token);
 101                 break;
 102         }
 103
 104         return ret;
 105 }
 106
 107 static void usage_command_usagestr(const char * const *usagestr,
 108                                    const char *token, int full, int err)
 109 {
 110         FILE *outf = err ? stderr : stdout;
 111         int ret;
 112
 113         ret = usage_command_internal(usagestr, token, full, 0, outf);
 114         if (!ret)
 115                 fputc('\n', outf);
 116 }
 117
 118 void usage_command(const struct cmd_struct *cmd, int full, int err)
 119 {
 120         usage_command_usagestr(cmd->usagestr, cmd->token, full, err);
 121 }
 122
 123 void usage(const char * const *usagestr)
 124 {
 125         usage_command_usagestr(usagestr, NULL, 1, 1);
 126         exit(1);
 127 }
 128
 129 static void usage_command_group_internal(const struct cmd_group *grp, int full,
 130                                          FILE *outf)
 131 {
 132         const struct cmd_struct *cmd = grp->commands;
 133         int do_sep = 0;
 134
 135         for (; cmd->token; cmd++) {
 136                 if (cmd->hidden)
 137                         continue;
 138
 139                 if (full && cmd != grp->commands)
 140                         fputc('\n', outf);
 141
 142                 if (!cmd->next) {
 143                         if (do_sep) {
 144                                 fputc('\n', outf);
 145                                 do_sep = 0;
 146                         }
 147
 148                         usage_command_internal(cmd->usagestr, cmd->token, full,
 149                                                1, outf);
 150                         continue;
 151                 }
 152
 153                 /* this is an entry point to a nested command group */
 154
 155                 if (!full && cmd != grp->commands)
 156                         fputc('\n', outf);
 157
 158                 usage_command_group_internal(cmd->next, full, outf);
 159
 160                 if (!full)
 161                         do_sep = 1;
 162         }
 163 }
 164
 165 void usage_command_group(const struct cmd_group *grp, int full, int err)
 166 {
 167         const char * const *usagestr = grp->usagestr;
 168         FILE *outf = err ? stderr : stdout;
 169
 170         if (usagestr && *usagestr) {
 171                 fprintf(outf, "usage: %s\n", *usagestr++);
 172                 while (*usagestr)
 173                         fprintf(outf, "   or: %s\n", *usagestr++);
 174         }
 175
 176         fputc('\n', outf);
 177         usage_command_group_internal(grp, full, outf);
 178         fputc('\n', outf);
 179
 180         if (grp->infostr)
 181                 fprintf(outf, "%s\n", grp->infostr);
 182 }
 183
 184 void help_unknown_token(const char *arg, const struct cmd_group *grp)
 185 {
 186         fprintf(stderr, "%s: unknown token '%s'\n", argv0_buf, arg);
 187         usage_command_group(grp, 0, 1);
 188         exit(1);
 189 }
 190
 191 void help_ambiguous_token(const char *arg, const struct cmd_group *grp)
 192 {
 193         const struct cmd_struct *cmd = grp->commands;
 194
 195         fprintf(stderr, "%s: ambiguous token '%s'\n", argv0_buf, arg);
 196         fprintf(stderr, "\nDid you mean one of these ?\n");
 197
 198         for (; cmd->token; cmd++) {
 199                 if (!prefixcmp(cmd->token, arg))
 200                         fprintf(stderr, "\t%s\n", cmd->token);
 201         }
 202
 203         exit(1);
 204 }
 205
 206 void help_command_group(const struct cmd_group *grp, int argc, char **argv)
 207 {
 208         int full = 0;
 209
 210         if (argc > 1) {
 211                 if (!strcmp(argv[1], "--full"))
 212                         full = 1;
 213         }
 214
 215         usage_command_group(grp, full, 0);
 216 }