btrfs.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 #define _GNU_SOURCE
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21
  22 #include "commands.h"
  23 #include "version.h"
  24
  25 static const char * const btrfs_cmd_group_usage[] = {
  26         "btrfs [--help] [--version] <group> [<group>...] <command> [<args>]",
  27         NULL
  28 };
  29
  30 static const char btrfs_cmd_group_info[] =
  31         "Use --help as an argument for information on a specific group or command.";
  32
  33 char argv0_buf[ARGV0_BUF_SIZE] = "btrfs";
  34
  35 static inline const char *skip_prefix(const char *str, const char *prefix)
  36 {
  37         size_t len = strlen(prefix);
  38         return strncmp(str, prefix, len) ? NULL : str + len;
  39 }
  40
  41 int prefixcmp(const char *str, const char *prefix)
  42 {
  43         for (; ; str++, prefix++)
  44                 if (!*prefix)
  45                         return 0;
  46                 else if (*str != *prefix)
  47                         return (unsigned char)*prefix - (unsigned char)*str;
  48 }
  49
  50 static int parse_one_token(const char *arg, const struct cmd_group *grp,
  51                            const struct cmd_struct **cmd_ret)
  52 {
  53         const struct cmd_struct *cmd = grp->commands;
  54         const struct cmd_struct *abbrev_cmd = NULL, *ambiguous_cmd = NULL;
  55
  56         for (; cmd->token; cmd++) {
  57                 const char *rest;
  58
  59                 rest = skip_prefix(arg, cmd->token);
  60                 if (!rest) {
  61                         if (!prefixcmp(cmd->token, arg)) {
  62                                 if (abbrev_cmd) {
  63                                         /*
  64                                          * If this is abbreviated, it is
  65                                          * ambiguous. So when there is no
  66                                          * exact match later, we need to
  67                                          * error out.
  68                                          */
  69                                         ambiguous_cmd = abbrev_cmd;
  70                                 }
  71                                 abbrev_cmd = cmd;
  72                         }
  73                         continue;
  74                 }
  75                 if (*rest)
  76                         continue;
  77
  78                 *cmd_ret = cmd;
  79                 return 0;
  80         }
  81
  82         if (ambiguous_cmd)
  83                 return -2;
  84
  85         if (abbrev_cmd) {
  86                 *cmd_ret = abbrev_cmd;
  87                 return 0;
  88         }
  89
  90         return -1;
  91 }
  92
  93 static const struct cmd_struct *
  94 parse_command_token(const char *arg, const struct cmd_group *grp)
  95 {
  96         const struct cmd_struct *cmd;
  97
  98         switch(parse_one_token(arg, grp, &cmd)) {
  99         case -1:
 100                 help_unknown_token(arg, grp);
 101         case -2:
 102                 help_ambiguous_token(arg, grp);
 103         }
 104
 105         return cmd;
 106 }
 107
 108 void handle_help_options_next_level(const struct cmd_struct *cmd,
 109                                     int argc, char **argv)
 110 {
 111         if (argc < 2)
 112                 return;
 113
 114         if (!strcmp(argv[1], "--help")) {
 115                 if (cmd->next) {
 116                         argc--;
 117                         argv++;
 118                         help_command_group(cmd->next, argc, argv);
 119                 } else {
 120                         usage_command(cmd, 1, 0);
 121                 }
 122
 123                 exit(0);
 124         }
 125 }
 126
 127 static void fixup_argv0(char **argv, const char *token)
 128 {
 129         int len = strlen(argv0_buf);
 130
 131         snprintf(argv0_buf + len, sizeof(argv0_buf) - len, " %s", token);
 132         argv[0] = argv0_buf;
 133 }
 134
 135 int handle_command_group(const struct cmd_group *grp, int argc,
 136                          char **argv)
 137
 138 {
 139         const struct cmd_struct *cmd;
 140
 141         argc--;
 142         argv++;
 143         if (argc < 1) {
 144                 usage_command_group(grp, 0, 0);
 145                 exit(1);
 146         }
 147
 148         cmd = parse_command_token(argv[0], grp);
 149
 150         handle_help_options_next_level(cmd, argc, argv);
 151
 152         fixup_argv0(argv, cmd->token);
 153         return cmd->fn(argc, argv);
 154 }
 155
 156 int check_argc_exact(int nargs, int expected)
 157 {
 158         if (nargs < expected)
 159                 fprintf(stderr, "%s: too few arguments\n", argv0_buf);
 160         if (nargs > expected)
 161                 fprintf(stderr, "%s: too many arguments\n", argv0_buf);
 162
 163         return nargs != expected;
 164 }
 165
 166 int check_argc_min(int nargs, int expected)
 167 {
 168         if (nargs < expected) {
 169                 fprintf(stderr, "%s: too few arguments\n", argv0_buf);
 170                 return 1;
 171         }
 172
 173         return 0;
 174 }
 175
 176 int check_argc_max(int nargs, int expected)
 177 {
 178         if (nargs > expected) {
 179                 fprintf(stderr, "%s: too many arguments\n", argv0_buf);
 180                 return 1;
 181         }
 182
 183         return 0;
 184 }
 185
 186 const struct cmd_group btrfs_cmd_group;
 187
 188 static const char * const cmd_help_usage[] = {
 189         "btrfs help [--full]",
 190         "Dislay help information",
 191         "",
 192         "--full     display detailed help on every command",
 193         NULL
 194 };
 195
 196 static int cmd_help(int argc, char **argv)
 197 {
 198         help_command_group(&btrfs_cmd_group, argc, argv);
 199         return 0;
 200 }
 201
 202 static const char * const cmd_version_usage[] = {
 203         "btrfs version",
 204         "Display btrfs-progs version",
 205         NULL
 206 };
 207
 208 static int cmd_version(int argc, char **argv)
 209 {
 210         printf("%s\n", BTRFS_BUILD_VERSION);
 211         return 0;
 212 }
 213
 214 static int handle_options(int *argc, char ***argv)
 215 {
 216         char **orig_argv = *argv;
 217
 218         while (*argc > 0) {
 219                 const char *arg = (*argv)[0];
 220                 if (arg[0] != '-')
 221                         break;
 222
 223                 if (!strcmp(arg, "--help")) {
 224                         break;
 225                 } else if (!strcmp(arg, "--version")) {
 226                         break;
 227                 } else {
 228                         fprintf(stderr, "Unknown option: %s\n", arg);
 229                         fprintf(stderr, "usage: %s\n",
 230                                 btrfs_cmd_group.usagestr[0]);
 231                         exit(129);
 232                 }
 233
 234                 (*argv)++;
 235                 (*argc)--;
 236         }
 237
 238         return (*argv) - orig_argv;
 239 }
 240
 241 const struct cmd_group btrfs_cmd_group = {
 242         btrfs_cmd_group_usage, btrfs_cmd_group_info, {
 243                 { "subvolume", cmd_subvolume, NULL, &subvolume_cmd_group, 0 },
 244                 { "filesystem", cmd_filesystem, NULL, &filesystem_cmd_group, 0 },
 245                 { "balance", cmd_balance, NULL, &balance_cmd_group, 0 },
 246                 { "device", cmd_device, NULL, &device_cmd_group, 0 },
 247                 { "scrub", cmd_scrub, NULL, &scrub_cmd_group, 0 },
 248                 { "inspect-internal", cmd_inspect, NULL, &inspect_cmd_group, 0 },
 249                 { "send", cmd_send, NULL, &send_cmd_group, 0 },
 250                 { "receive", cmd_receive, NULL, &receive_cmd_group, 0 },
 251                 { "help", cmd_help, cmd_help_usage, NULL, 0 },
 252                 { "version", cmd_version, cmd_version_usage, NULL, 0 },
 253                 { 0, 0, 0, 0, 0 }
 254         },
 255 };
 256
 257 int main(int argc, char **argv)
 258 {
 259         const struct cmd_struct *cmd;
 260
 261         argc--;
 262         argv++;
 263         handle_options(&argc, &argv);
 264         if (argc > 0) {
 265                 if (!prefixcmp(argv[0], "--"))
 266                         argv[0] += 2;
 267         } else {
 268                 usage_command_group(&btrfs_cmd_group, 0, 0);
 269                 exit(1);
 270         }
 271
 272         cmd = parse_command_token(argv[0], &btrfs_cmd_group);
 273
 274         handle_help_options_next_level(cmd, argc, argv);
 275
 276         fixup_argv0(argv, cmd->token);
 277         exit(cmd->fn(argc, argv));
 278 }