btrfs-progs/btrfs.c
Ilya Dryomov 08b51bd731 Btrfs-progs: allow multi-line command group synopsis
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-02-08 18:55:51 +02:00

277 lines
5.8 KiB
C

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "commands.h"
#include "version.h"
static const char * const btrfs_cmd_group_usage[] = {
"btrfs [--help] [--version] <group> [<group>...] <command> [<args>]",
NULL
};
static const char btrfs_cmd_group_info[] =
"Use --help as an argument for information on a specific group or command.";
char argv0_buf[ARGV0_BUF_SIZE] = "btrfs";
static inline const char *skip_prefix(const char *str, const char *prefix)
{
size_t len = strlen(prefix);
return strncmp(str, prefix, len) ? NULL : str + len;
}
int prefixcmp(const char *str, const char *prefix)
{
for (; ; str++, prefix++)
if (!*prefix)
return 0;
else if (*str != *prefix)
return (unsigned char)*prefix - (unsigned char)*str;
}
static int parse_one_token(const char *arg, const struct cmd_group *grp,
const struct cmd_struct **cmd_ret)
{
const struct cmd_struct *cmd = grp->commands;
const struct cmd_struct *abbrev_cmd = NULL, *ambiguous_cmd = NULL;
for (; cmd->token; cmd++) {
const char *rest;
rest = skip_prefix(arg, cmd->token);
if (!rest) {
if (!prefixcmp(cmd->token, arg)) {
if (abbrev_cmd) {
/*
* If this is abbreviated, it is
* ambiguous. So when there is no
* exact match later, we need to
* error out.
*/
ambiguous_cmd = abbrev_cmd;
}
abbrev_cmd = cmd;
}
continue;
}
if (*rest)
continue;
*cmd_ret = cmd;
return 0;
}
if (ambiguous_cmd)
return -2;
if (abbrev_cmd) {
*cmd_ret = abbrev_cmd;
return 0;
}
return -1;
}
static const struct cmd_struct *
parse_command_token(const char *arg, const struct cmd_group *grp)
{
const struct cmd_struct *cmd;
switch(parse_one_token(arg, grp, &cmd)) {
case -1:
help_unknown_token(arg, grp);
case -2:
help_ambiguous_token(arg, grp);
}
return cmd;
}
void handle_help_options_next_level(const struct cmd_struct *cmd,
int argc, char **argv)
{
if (argc < 2)
return;
if (!strcmp(argv[1], "--help")) {
if (cmd->next) {
argc--;
argv++;
help_command_group(cmd->next, argc, argv);
} else {
usage_command(cmd, 1, 0);
}
exit(0);
}
}
static void fixup_argv0(char **argv, const char *token)
{
int len = strlen(argv0_buf);
snprintf(argv0_buf + len, sizeof(argv0_buf) - len, " %s", token);
argv[0] = argv0_buf;
}
int handle_command_group(const struct cmd_group *grp, int argc,
char **argv)
{
const struct cmd_struct *cmd;
argc--;
argv++;
if (argc < 1) {
usage_command_group(grp, 0, 0);
exit(1);
}
cmd = parse_command_token(argv[0], grp);
handle_help_options_next_level(cmd, argc, argv);
fixup_argv0(argv, cmd->token);
return cmd->fn(argc, argv);
}
int check_argc_exact(int nargs, int expected)
{
if (nargs < expected)
fprintf(stderr, "%s: too few arguments\n", argv0_buf);
if (nargs > expected)
fprintf(stderr, "%s: too many arguments\n", argv0_buf);
return nargs != expected;
}
int check_argc_min(int nargs, int expected)
{
if (nargs < expected) {
fprintf(stderr, "%s: too few arguments\n", argv0_buf);
return 1;
}
return 0;
}
int check_argc_max(int nargs, int expected)
{
if (nargs > expected) {
fprintf(stderr, "%s: too many arguments\n", argv0_buf);
return 1;
}
return 0;
}
const struct cmd_group btrfs_cmd_group;
static const char * const cmd_help_usage[] = {
"btrfs help [--full]",
"Dislay help information",
"",
"--full display detailed help on every command",
NULL
};
static int cmd_help(int argc, char **argv)
{
help_command_group(&btrfs_cmd_group, argc, argv);
return 0;
}
static const char * const cmd_version_usage[] = {
"btrfs version",
"Display btrfs-progs version",
NULL
};
static int cmd_version(int argc, char **argv)
{
printf("%s\n", BTRFS_BUILD_VERSION);
return 0;
}
static int handle_options(int *argc, char ***argv)
{
char **orig_argv = *argv;
while (*argc > 0) {
const char *arg = (*argv)[0];
if (arg[0] != '-')
break;
if (!strcmp(arg, "--help")) {
break;
} else if (!strcmp(arg, "--version")) {
break;
} else {
fprintf(stderr, "Unknown option: %s\n", arg);
fprintf(stderr, "usage: %s\n",
btrfs_cmd_group.usagestr[0]);
exit(129);
}
(*argv)++;
(*argc)--;
}
return (*argv) - orig_argv;
}
const struct cmd_group btrfs_cmd_group = {
btrfs_cmd_group_usage, btrfs_cmd_group_info, {
{ "subvolume", cmd_subvolume, NULL, &subvolume_cmd_group, 0 },
{ "filesystem", cmd_filesystem, NULL, &filesystem_cmd_group, 0 },
{ "balance", cmd_balance, NULL, &balance_cmd_group, 0 },
{ "device", cmd_device, NULL, &device_cmd_group, 0 },
{ "scrub", cmd_scrub, NULL, &scrub_cmd_group, 0 },
{ "inspect-internal", cmd_inspect, NULL, &inspect_cmd_group, 0 },
{ "help", cmd_help, cmd_help_usage, NULL, 0 },
{ "version", cmd_version, cmd_version_usage, NULL, 0 },
{ 0, 0, 0, 0, 0 }
},
};
int main(int argc, char **argv)
{
const struct cmd_struct *cmd;
argc--;
argv++;
handle_options(&argc, &argv);
if (argc > 0) {
if (!prefixcmp(argv[0], "--"))
argv[0] += 2;
} else {
usage_command_group(&btrfs_cmd_group, 0, 0);
exit(1);
}
cmd = parse_command_token(argv[0], &btrfs_cmd_group);
handle_help_options_next_level(cmd, argc, argv);
fixup_argv0(argv, cmd->token);
exit(cmd->fn(argc, argv));
}