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 #define USAGE_SHORT             1U
  26 #define USAGE_LONG              2U
  27 #define USAGE_OPTIONS           4U
  28 #define USAGE_LISTING           8U
  29
  30 static int do_usage_one_command(const char * const *usagestr,
  31                                 unsigned int flags, FILE *outf)
  32 {
  33         int pad = 4;
  34
  35         if (!usagestr || !*usagestr)
  36                 return -1;
  37
  38         fprintf(outf, "%s%s\n", (flags & USAGE_LISTING) ? "    " : "usage: ",
  39                 *usagestr++);
  40
  41         /* a short one-line description (mandatory) */
  42         if ((flags & USAGE_SHORT) == 0)
  43                 return 0;
  44         else if (!*usagestr)
  45                 return -2;
  46
  47         if (flags & USAGE_LISTING)
  48                 pad = 8;
  49         else
  50                 fputc('\n', outf);
  51
  52         fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
  53
  54         /* a long (possibly multi-line) description (optional) */
  55         if (!*usagestr || ((flags & USAGE_LONG) == 0))
  56                 return 0;
  57
  58         if (**usagestr)
  59                 fputc('\n', outf);
  60         while (*usagestr && **usagestr)
  61                 fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
  62
  63         /* options (optional) */
  64         if (!*usagestr || ((flags & USAGE_OPTIONS) == 0))
  65                 return 0;
  66
  67         /*
  68          * options (if present) should always (even if there is no long
  69          * description) be prepended with an empty line, skip it
  70          */
  71         usagestr++;
  72
  73         fputc('\n', outf);
  74         while (*usagestr)
  75                 fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
  76
  77         return 0;
  78 }
  79
  80 static int usage_command_internal(const char * const *usagestr,
  81                                   const char *token, int full, int lst,
  82                                   int alias, FILE *outf)
  83 {
  84         unsigned int flags = 0;
  85         int ret;
  86
  87         if (!alias)
  88                 flags |= USAGE_SHORT;
  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, 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->flags & 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, cmd->flags & CMD_ALIAS, 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_short(const struct cmd_group *grp)
 166 {
 167         const char * const *usagestr = grp->usagestr;
 168         FILE *outf = stdout;
 169         const struct cmd_struct *cmd;
 170
 171         if (usagestr && *usagestr) {
 172                 fprintf(outf, "usage: %s\n", *usagestr++);
 173                 while (*usagestr)
 174                         fprintf(outf, "   or: %s\n", *usagestr++);
 175         }
 176
 177         fputc('\n', outf);
 178
 179         fprintf(outf, "Command groups:\n");
 180         for (cmd = grp->commands; cmd->token; cmd++) {
 181                 if (cmd->flags & CMD_HIDDEN)
 182                         continue;
 183
 184                 if (!cmd->next)
 185                         continue;
 186
 187                 fprintf(outf, "  %-16s  %s\n", cmd->token, cmd->next->infostr);
 188         }
 189
 190         fprintf(outf, "\nCommands:\n");
 191         for (cmd = grp->commands; cmd->token; cmd++) {
 192                 if (cmd->flags & CMD_HIDDEN)
 193                         continue;
 194
 195                 if (cmd->next)
 196                         continue;
 197
 198                 fprintf(outf, "  %-16s  %s\n", cmd->token, cmd->usagestr[1]);
 199         }
 200
 201         fputc('\n', outf);
 202         fprintf(stderr, "For an overview of a given command use 'btrfs command --help'\n");
 203         fprintf(stderr, "or 'btrfs [command...] --help --full' to print all available options.\n");
 204         fprintf(stderr, "Any command name can be shortened as far as it stays unambiguous,\n");
 205         fprintf(stderr, "however it is recommended to use full command names in scripts.\n");
 206         fprintf(stderr, "All command groups have their manual page named 'btrfs-<group>'.\n");
 207 }
 208
 209 void usage_command_group(const struct cmd_group *grp, int full, int err)
 210 {
 211         const char * const *usagestr = grp->usagestr;
 212         FILE *outf = err ? stderr : stdout;
 213
 214         if (usagestr && *usagestr) {
 215                 fprintf(outf, "usage: %s\n", *usagestr++);
 216                 while (*usagestr)
 217                         fprintf(outf, "   or: %s\n", *usagestr++);
 218         }
 219
 220         fputc('\n', outf);
 221         usage_command_group_internal(grp, full, outf);
 222         fputc('\n', outf);
 223
 224         if (grp->infostr)
 225                 fprintf(outf, "%s\n", grp->infostr);
 226 }
 227
 228 void help_unknown_token(const char *arg, const struct cmd_group *grp)
 229 {
 230         fprintf(stderr, "%s: unknown token '%s'\n", get_argv0_buf(), arg);
 231         usage_command_group(grp, 0, 1);
 232         exit(1);
 233 }
 234
 235 void help_ambiguous_token(const char *arg, const struct cmd_group *grp)
 236 {
 237         const struct cmd_struct *cmd = grp->commands;
 238
 239         fprintf(stderr, "%s: ambiguous token '%s'\n", get_argv0_buf(), arg);
 240         fprintf(stderr, "\nDid you mean one of these ?\n");
 241
 242         for (; cmd->token; cmd++) {
 243                 if (!prefixcmp(cmd->token, arg))
 244                         fprintf(stderr, "\t%s\n", cmd->token);
 245         }
 246
 247         exit(1);
 248 }
 249
 250 void help_command_group(const struct cmd_group *grp, int argc, char **argv)
 251 {
 252         int full = 0;
 253
 254         if (argc > 1) {
 255                 if (!strcmp(argv[1], "--full"))
 256                         full = 1;
 257         }
 258
 259         usage_command_group(grp, full, 0);
 260 }