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 "crc32c.h"
  23 #include "commands.h"
  24 #include "version.h"
  25
  26 static const char * const btrfs_cmd_group_usage[] = {
  27         "btrfs [--help] [--version] <group> [<group>...] <command> [<args>]",
  28         NULL
  29 };
  30
  31 static const char btrfs_cmd_group_info[] =
  32         "Use --help as an argument for information on a specific group or command.";
  33
  34 char argv0_buf[ARGV0_BUF_SIZE] = "btrfs";
  35
  36 static inline const char *skip_prefix(const char *str, const char *prefix)
  37 {
  38         size_t len = strlen(prefix);
  39         return strncmp(str, prefix, len) ? NULL : str + len;
  40 }
  41
  42 int prefixcmp(const char *str, const char *prefix)
  43 {
  44         for (; ; str++, prefix++)
  45                 if (!*prefix)
  46                         return 0;
  47                 else if (*str != *prefix)
  48                         return (unsigned char)*prefix - (unsigned char)*str;
  49 }
  50
  51 static int parse_one_token(const char *arg, const struct cmd_group *grp,
  52                            const struct cmd_struct **cmd_ret)
  53 {
  54         const struct cmd_struct *cmd = grp->commands;
  55         const struct cmd_struct *abbrev_cmd = NULL, *ambiguous_cmd = NULL;
  56
  57         for (; cmd->token; cmd++) {
  58                 const char *rest;
  59
  60                 rest = skip_prefix(arg, cmd->token);
  61                 if (!rest) {
  62                         if (!prefixcmp(cmd->token, arg)) {
  63                                 if (abbrev_cmd) {
  64                                         /*
  65                                          * If this is abbreviated, it is
  66                                          * ambiguous. So when there is no
  67                                          * exact match later, we need to
  68                                          * error out.
  69                                          */
  70                                         ambiguous_cmd = abbrev_cmd;
  71                                 }
  72                                 abbrev_cmd = cmd;
  73                         }
  74                         continue;
  75                 }
  76                 if (*rest)
  77                         continue;
  78
  79                 *cmd_ret = cmd;
  80                 return 0;
  81         }
  82
  83         if (ambiguous_cmd)
  84                 return -2;
  85
  86         if (abbrev_cmd) {
  87                 *cmd_ret = abbrev_cmd;
  88                 return 0;
  89         }
  90
  91         return -1;
  92 }
  93
  94 static const struct cmd_struct *
  95 parse_command_token(const char *arg, const struct cmd_group *grp)
  96 {
  97         const struct cmd_struct *cmd = NULL;
  98
  99         switch(parse_one_token(arg, grp, &cmd)) {
 100         case -1:
 101                 help_unknown_token(arg, grp);
 102         case -2:
 103                 help_ambiguous_token(arg, grp);
 104         }
 105
 106         return cmd;
 107 }
 108
 109 void handle_help_options_next_level(const struct cmd_struct *cmd,
 110                                     int argc, char **argv)
 111 {
 112         if (argc < 2)
 113                 return;
 114
 115         if (!strcmp(argv[1], "--help")) {
 116                 if (cmd->next) {
 117                         argc--;
 118                         argv++;
 119                         help_command_group(cmd->next, argc, argv);
 120                 } else {
 121                         usage_command(cmd, 1, 0);
 122                 }
 123
 124                 exit(0);
 125         }
 126 }
 127
 128 static void fixup_argv0(char **argv, const char *token)
 129 {
 130         int len = strlen(argv0_buf);
 131
 132         snprintf(argv0_buf + len, sizeof(argv0_buf) - len, " %s", token);
 133         argv[0] = argv0_buf;
 134 }
 135
 136 int handle_command_group(const struct cmd_group *grp, int argc,
 137                          char **argv)
 138
 139 {
 140         const struct cmd_struct *cmd;
 141
 142         argc--;
 143         argv++;
 144         if (argc < 1) {
 145                 usage_command_group(grp, 0, 0);
 146                 exit(1);
 147         }
 148
 149         cmd = parse_command_token(argv[0], grp);
 150
 151         handle_help_options_next_level(cmd, argc, argv);
 152
 153         fixup_argv0(argv, cmd->token);
 154         return cmd->fn(argc, argv);
 155 }
 156
 157 int check_argc_exact(int nargs, int expected)
 158 {
 159         if (nargs < expected)
 160                 fprintf(stderr, "%s: too few arguments\n", argv0_buf);
 161         if (nargs > expected)
 162                 fprintf(stderr, "%s: too many arguments\n", argv0_buf);
 163
 164         return nargs != expected;
 165 }
 166
 167 int check_argc_min(int nargs, int expected)
 168 {
 169         if (nargs < expected) {
 170                 fprintf(stderr, "%s: too few arguments\n", argv0_buf);
 171                 return 1;
 172         }
 173
 174         return 0;
 175 }
 176
 177 int check_argc_max(int nargs, int expected)
 178 {
 179         if (nargs > expected) {
 180                 fprintf(stderr, "%s: too many arguments\n", argv0_buf);
 181                 return 1;
 182         }
 183
 184         return 0;
 185 }
 186
 187 const struct cmd_group btrfs_cmd_group;
 188
 189 static const char * const cmd_help_usage[] = {
 190         "btrfs help [--full]",
 191         "Dislay help information",
 192         "",
 193         "--full     display detailed help on every command",
 194         NULL
 195 };
 196
 197 static int cmd_help(int argc, char **argv)
 198 {
 199         help_command_group(&btrfs_cmd_group, argc, argv);
 200         return 0;
 201 }
 202
 203 static const char * const cmd_version_usage[] = {
 204         "btrfs version",
 205         "Display btrfs-progs version",
 206         NULL
 207 };
 208
 209 static int cmd_version(int argc, char **argv)
 210 {
 211         printf("%s\n", BTRFS_BUILD_VERSION);
 212         return 0;
 213 }
 214
 215 static int handle_options(int *argc, char ***argv)
 216 {
 217         char **orig_argv = *argv;
 218
 219         while (*argc > 0) {
 220                 const char *arg = (*argv)[0];
 221                 if (arg[0] != '-')
 222                         break;
 223
 224                 if (!strcmp(arg, "--help")) {
 225                         break;
 226                 } else if (!strcmp(arg, "--version")) {
 227                         break;
 228                 } else {
 229                         fprintf(stderr, "Unknown option: %s\n", arg);
 230                         fprintf(stderr, "usage: %s\n",
 231                                 btrfs_cmd_group.usagestr[0]);
 232                         exit(129);
 233                 }
 234
 235                 (*argv)++;
 236                 (*argc)--;
 237         }
 238
 239         return (*argv) - orig_argv;
 240 }
 241
 242 const struct cmd_group btrfs_cmd_group = {
 243         btrfs_cmd_group_usage, btrfs_cmd_group_info, {
 244                 { "subvolume", cmd_subvolume, NULL, &subvolume_cmd_group, 0 },
 245                 { "filesystem", cmd_filesystem, NULL, &filesystem_cmd_group, 0 },
 246                 { "balance", cmd_balance, NULL, &balance_cmd_group, 0 },
 247                 { "device", cmd_device, NULL, &device_cmd_group, 0 },
 248                 { "scrub", cmd_scrub, NULL, &scrub_cmd_group, 0 },
 249                 { "inspect-internal", cmd_inspect, NULL, &inspect_cmd_group, 0 },
 250                 { "send", cmd_send, NULL, &send_cmd_group, 0 },
 251                 { "receive", cmd_receive, NULL, &receive_cmd_group, 0 },
 252                 { "quota", cmd_quota, NULL, &quota_cmd_group, 0 },
 253                 { "qgroup", cmd_qgroup, NULL, &qgroup_cmd_group, 0 },
 254                 { "help", cmd_help, cmd_help_usage, NULL, 0 },
 255                 { "version", cmd_version, cmd_version_usage, NULL, 0 },
 256                 { 0, 0, 0, 0, 0 }
 257         },
 258 };
 259
 260 int main(int argc, char **argv)
 261 {
 262         const struct cmd_struct *cmd;
 263
 264         crc32c_optimization_init();
 265
 266         argc--;
 267         argv++;
 268         handle_options(&argc, &argv);
 269         if (argc > 0) {
 270                 if (!prefixcmp(argv[0], "--"))
 271                         argv[0] += 2;
 272         } else {
 273                 usage_command_group(&btrfs_cmd_group, 0, 0);
 274                 exit(1);
 275         }
 276
 277         cmd = parse_command_token(argv[0], &btrfs_cmd_group);
 278
 279         handle_help_options_next_level(cmd, argc, argv);
 280
 281         fixup_argv0(argv, cmd->token);
 282         exit(cmd->fn(argc, argv));
 283 }