qemu/qemu-img.c
blueswir1 d2c639d6dc Synch code, help and docs
Rearrange code, help printout and docs so that they are in the same
(hopefully more logical) order for easier maintenance.

Add help and docs for undocumented options.

Reformat slightly for more consistent help output.

Add comments to encourage better synchronization in the future.


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6432 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-24 18:19:25 +00:00

884 lines
25 KiB
C

/*
* QEMU disk image utility
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu-common.h"
#include "osdep.h"
#include "block_int.h"
#include <assert.h>
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif
/* Default to cache=writeback as data integrity is not important for qemu-tcg. */
#define BRDV_O_FLAGS BDRV_O_CACHE_WB
static void noreturn error(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
fprintf(stderr, "qemu-img: ");
vfprintf(stderr, fmt, ap);
fprintf(stderr, "\n");
exit(1);
va_end(ap);
}
static void format_print(void *opaque, const char *name)
{
printf(" %s", name);
}
/* Please keep in synch with qemu-img.texi */
static void help(void)
{
printf("qemu-img version " QEMU_VERSION ", Copyright (c) 2004-2008 Fabrice Bellard\n"
"usage: qemu-img command [command options]\n"
"QEMU disk image utility\n"
"\n"
"Command syntax:\n"
" create [-e] [-6] [-b base_image] [-f fmt] filename [size]\n"
" commit [-f fmt] filename\n"
" convert [-c] [-e] [-6] [-f fmt] [-O output_fmt] [-B output_base_image] filename [filename2 [...]] output_filename\n"
" info [-f fmt] filename\n"
" snapshot [-l | -a snapshot | -c snapshot | -d snapshot] filename\n"
"\n"
"Command parameters:\n"
" 'filename' is a disk image filename\n"
" 'base_image' is the read-only disk image which is used as base for a copy on\n"
" write image; the copy on write image only stores the modified data\n"
" 'output_base_image' forces the output image to be created as a copy on write\n"
" image of the specified base image; 'output_base_image' should have the same\n"
" content as the input's base image, however the path, image format, etc may\n"
" differ\n"
" 'fmt' is the disk image format. It is guessed automatically in most cases\n"
" 'size' is the disk image size in kilobytes. Optional suffixes\n"
" 'M' (megabyte, 1024 * 1024) and 'G' (gigabyte, 1024 * 1024 * 1024) are"
" supported any @code{k} or @code{K} is ignored\n"
" 'output_filename' is the destination disk image filename\n"
" 'output_fmt' is the destination format\n"
" '-c' indicates that target image must be compressed (qcow format only)\n"
" '-e' indicates that the target image must be encrypted (qcow format only)\n"
" '-6' indicates that the target image must use compatibility level 6 (vmdk format only)\n"
" '-h' with or without a command shows this help and lists the supported formats\n"
"\n"
"Parameters to snapshot subcommand:\n"
" 'snapshot' is the name of the snapshot to create, apply or delete\n"
" '-a' applies a snapshot (revert disk to saved state)\n"
" '-c' creates a snapshot\n"
" '-d' deletes a snapshot\n"
" '-l' lists all snapshots in the given image\n"
);
printf("\nSupported formats:");
bdrv_iterate_format(format_print, NULL);
printf("\n");
exit(1);
}
#if defined(WIN32)
/* XXX: put correct support for win32 */
static int read_password(char *buf, int buf_size)
{
int c, i;
printf("Password: ");
fflush(stdout);
i = 0;
for(;;) {
c = getchar();
if (c == '\n')
break;
if (i < (buf_size - 1))
buf[i++] = c;
}
buf[i] = '\0';
return 0;
}
#else
#include <termios.h>
static struct termios oldtty;
static void term_exit(void)
{
tcsetattr (0, TCSANOW, &oldtty);
}
static void term_init(void)
{
struct termios tty;
tcgetattr (0, &tty);
oldtty = tty;
tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
|INLCR|IGNCR|ICRNL|IXON);
tty.c_oflag |= OPOST;
tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
tty.c_cflag &= ~(CSIZE|PARENB);
tty.c_cflag |= CS8;
tty.c_cc[VMIN] = 1;
tty.c_cc[VTIME] = 0;
tcsetattr (0, TCSANOW, &tty);
atexit(term_exit);
}
static int read_password(char *buf, int buf_size)
{
uint8_t ch;
int i, ret;
printf("password: ");
fflush(stdout);
term_init();
i = 0;
for(;;) {
ret = read(0, &ch, 1);
if (ret == -1) {
if (errno == EAGAIN || errno == EINTR) {
continue;
} else {
ret = -1;
break;
}
} else if (ret == 0) {
ret = -1;
break;
} else {
if (ch == '\r') {
ret = 0;
break;
}
if (i < (buf_size - 1))
buf[i++] = ch;
}
}
term_exit();
buf[i] = '\0';
printf("\n");
return ret;
}
#endif
static BlockDriverState *bdrv_new_open(const char *filename,
const char *fmt)
{
BlockDriverState *bs;
BlockDriver *drv;
char password[256];
bs = bdrv_new("");
if (!bs)
error("Not enough memory");
if (fmt) {
drv = bdrv_find_format(fmt);
if (!drv)
error("Unknown file format '%s'", fmt);
} else {
drv = NULL;
}
if (bdrv_open2(bs, filename, BRDV_O_FLAGS, drv) < 0) {
error("Could not open '%s'", filename);
}
if (bdrv_is_encrypted(bs)) {
printf("Disk image '%s' is encrypted.\n", filename);
if (read_password(password, sizeof(password)) < 0)
error("No password given");
if (bdrv_set_key(bs, password) < 0)
error("invalid password");
}
return bs;
}
static int img_create(int argc, char **argv)
{
int c, ret, flags;
const char *fmt = "raw";
const char *filename;
const char *base_filename = NULL;
uint64_t size;
const char *p;
BlockDriver *drv;
flags = 0;
for(;;) {
c = getopt(argc, argv, "b:f:he6");
if (c == -1)
break;
switch(c) {
case 'h':
help();
break;
case 'b':
base_filename = optarg;
break;
case 'f':
fmt = optarg;
break;
case 'e':
flags |= BLOCK_FLAG_ENCRYPT;
break;
case '6':
flags |= BLOCK_FLAG_COMPAT6;
break;
}
}
if (optind >= argc)
help();
filename = argv[optind++];
size = 0;
if (base_filename) {
BlockDriverState *bs;
bs = bdrv_new_open(base_filename, NULL);
bdrv_get_geometry(bs, &size);
size *= 512;
bdrv_delete(bs);
} else {
if (optind >= argc)
help();
p = argv[optind];
size = strtoul(p, (char **)&p, 0);
if (*p == 'M') {
size *= 1024 * 1024;
} else if (*p == 'G') {
size *= 1024 * 1024 * 1024;
} else if (*p == 'k' || *p == 'K' || *p == '\0') {
size *= 1024;
} else {
help();
}
}
drv = bdrv_find_format(fmt);
if (!drv)
error("Unknown file format '%s'", fmt);
printf("Formatting '%s', fmt=%s",
filename, fmt);
if (flags & BLOCK_FLAG_ENCRYPT)
printf(", encrypted");
if (flags & BLOCK_FLAG_COMPAT6)
printf(", compatibility level=6");
if (base_filename) {
printf(", backing_file=%s",
base_filename);
}
printf(", size=%" PRIu64 " kB\n", size / 1024);
ret = bdrv_create(drv, filename, size / 512, base_filename, flags);
if (ret < 0) {
if (ret == -ENOTSUP) {
error("Formatting or formatting option not supported for file format '%s'", fmt);
} else {
error("Error while formatting");
}
}
return 0;
}
static int img_commit(int argc, char **argv)
{
int c, ret;
const char *filename, *fmt;
BlockDriver *drv;
BlockDriverState *bs;
fmt = NULL;
for(;;) {
c = getopt(argc, argv, "f:h");
if (c == -1)
break;
switch(c) {
case 'h':
help();
break;
case 'f':
fmt = optarg;
break;
}
}
if (optind >= argc)
help();
filename = argv[optind++];
bs = bdrv_new("");
if (!bs)
error("Not enough memory");
if (fmt) {
drv = bdrv_find_format(fmt);
if (!drv)
error("Unknown file format '%s'", fmt);
} else {
drv = NULL;
}
if (bdrv_open2(bs, filename, BRDV_O_FLAGS, drv) < 0) {
error("Could not open '%s'", filename);
}
ret = bdrv_commit(bs);
switch(ret) {
case 0:
printf("Image committed.\n");
break;
case -ENOENT:
error("No disk inserted");
break;
case -EACCES:
error("Image is read-only");
break;
case -ENOTSUP:
error("Image is already committed");
break;
default:
error("Error while committing image");
break;
}
bdrv_delete(bs);
return 0;
}
static int is_not_zero(const uint8_t *sector, int len)
{
int i;
len >>= 2;
for(i = 0;i < len; i++) {
if (((uint32_t *)sector)[i] != 0)
return 1;
}
return 0;
}
/*
* Returns true iff the first sector pointed to by 'buf' contains at least
* a non-NUL byte.
*
* 'pnum' is set to the number of sectors (including and immediately following
* the first one) that are known to be in the same allocated/unallocated state.
*/
static int is_allocated_sectors(const uint8_t *buf, int n, int *pnum)
{
int v, i;
if (n <= 0) {
*pnum = 0;
return 0;
}
v = is_not_zero(buf, 512);
for(i = 1; i < n; i++) {
buf += 512;
if (v != is_not_zero(buf, 512))
break;
}
*pnum = i;
return v;
}
#define IO_BUF_SIZE 65536
static int img_convert(int argc, char **argv)
{
int c, ret, n, n1, bs_n, bs_i, flags, cluster_size, cluster_sectors;
const char *fmt, *out_fmt, *out_baseimg, *out_filename;
BlockDriver *drv;
BlockDriverState **bs, *out_bs;
int64_t total_sectors, nb_sectors, sector_num, bs_offset;
uint64_t bs_sectors;
uint8_t buf[IO_BUF_SIZE];
const uint8_t *buf1;
BlockDriverInfo bdi;
fmt = NULL;
out_fmt = "raw";
out_baseimg = NULL;
flags = 0;
for(;;) {
c = getopt(argc, argv, "f:O:B:hce6");
if (c == -1)
break;
switch(c) {
case 'h':
help();
break;
case 'f':
fmt = optarg;
break;
case 'O':
out_fmt = optarg;
break;
case 'B':
out_baseimg = optarg;
break;
case 'c':
flags |= BLOCK_FLAG_COMPRESS;
break;
case 'e':
flags |= BLOCK_FLAG_ENCRYPT;
break;
case '6':
flags |= BLOCK_FLAG_COMPAT6;
break;
}
}
bs_n = argc - optind - 1;
if (bs_n < 1) help();
out_filename = argv[argc - 1];
if (bs_n > 1 && out_baseimg)
error("-B makes no sense when concatenating multiple input images");
bs = calloc(bs_n, sizeof(BlockDriverState *));
if (!bs)
error("Out of memory");
total_sectors = 0;
for (bs_i = 0; bs_i < bs_n; bs_i++) {
bs[bs_i] = bdrv_new_open(argv[optind + bs_i], fmt);
if (!bs[bs_i])
error("Could not open '%s'", argv[optind + bs_i]);
bdrv_get_geometry(bs[bs_i], &bs_sectors);
total_sectors += bs_sectors;
}
drv = bdrv_find_format(out_fmt);
if (!drv)
error("Unknown file format '%s'", out_fmt);
if (flags & BLOCK_FLAG_COMPRESS && drv != &bdrv_qcow && drv != &bdrv_qcow2)
error("Compression not supported for this file format");
if (flags & BLOCK_FLAG_ENCRYPT && drv != &bdrv_qcow && drv != &bdrv_qcow2)
error("Encryption not supported for this file format");
if (flags & BLOCK_FLAG_COMPAT6 && drv != &bdrv_vmdk)
error("Alternative compatibility level not supported for this file format");
if (flags & BLOCK_FLAG_ENCRYPT && flags & BLOCK_FLAG_COMPRESS)
error("Compression and encryption not supported at the same time");
ret = bdrv_create(drv, out_filename, total_sectors, out_baseimg, flags);
if (ret < 0) {
if (ret == -ENOTSUP) {
error("Formatting not supported for file format '%s'", fmt);
} else {
error("Error while formatting '%s'", out_filename);
}
}
out_bs = bdrv_new_open(out_filename, out_fmt);
bs_i = 0;
bs_offset = 0;
bdrv_get_geometry(bs[0], &bs_sectors);
if (flags & BLOCK_FLAG_COMPRESS) {
if (bdrv_get_info(out_bs, &bdi) < 0)
error("could not get block driver info");
cluster_size = bdi.cluster_size;
if (cluster_size <= 0 || cluster_size > IO_BUF_SIZE)
error("invalid cluster size");
cluster_sectors = cluster_size >> 9;
sector_num = 0;
for(;;) {
int64_t bs_num;
int remainder;
uint8_t *buf2;
nb_sectors = total_sectors - sector_num;
if (nb_sectors <= 0)
break;
if (nb_sectors >= cluster_sectors)
n = cluster_sectors;
else
n = nb_sectors;
bs_num = sector_num - bs_offset;
assert (bs_num >= 0);
remainder = n;
buf2 = buf;
while (remainder > 0) {
int nlow;
while (bs_num == bs_sectors) {
bs_i++;
assert (bs_i < bs_n);
bs_offset += bs_sectors;
bdrv_get_geometry(bs[bs_i], &bs_sectors);
bs_num = 0;
/* printf("changing part: sector_num=%lld, "
"bs_i=%d, bs_offset=%lld, bs_sectors=%lld\n",
sector_num, bs_i, bs_offset, bs_sectors); */
}
assert (bs_num < bs_sectors);
nlow = (remainder > bs_sectors - bs_num) ? bs_sectors - bs_num : remainder;
if (bdrv_read(bs[bs_i], bs_num, buf2, nlow) < 0)
error("error while reading");
buf2 += nlow * 512;
bs_num += nlow;
remainder -= nlow;
}
assert (remainder == 0);
if (n < cluster_sectors)
memset(buf + n * 512, 0, cluster_size - n * 512);
if (is_not_zero(buf, cluster_size)) {
if (bdrv_write_compressed(out_bs, sector_num, buf,
cluster_sectors) != 0)
error("error while compressing sector %" PRId64,
sector_num);
}
sector_num += n;
}
/* signal EOF to align */
bdrv_write_compressed(out_bs, 0, NULL, 0);
} else {
sector_num = 0; // total number of sectors converted so far
for(;;) {
nb_sectors = total_sectors - sector_num;
if (nb_sectors <= 0)
break;
if (nb_sectors >= (IO_BUF_SIZE / 512))
n = (IO_BUF_SIZE / 512);
else
n = nb_sectors;
while (sector_num - bs_offset >= bs_sectors) {
bs_i ++;
assert (bs_i < bs_n);
bs_offset += bs_sectors;
bdrv_get_geometry(bs[bs_i], &bs_sectors);
/* printf("changing part: sector_num=%lld, bs_i=%d, "
"bs_offset=%lld, bs_sectors=%lld\n",
sector_num, bs_i, bs_offset, bs_sectors); */
}
if (n > bs_offset + bs_sectors - sector_num)
n = bs_offset + bs_sectors - sector_num;
/* If the output image is being created as a copy on write image,
assume that sectors which are unallocated in the input image
are present in both the output's and input's base images (no
need to copy them). */
if (out_baseimg) {
if (!bdrv_is_allocated(bs[bs_i], sector_num - bs_offset, n, &n1)) {
sector_num += n1;
continue;
}
/* The next 'n1' sectors are allocated in the input image. Copy
only those as they may be followed by unallocated sectors. */
n = n1;
}
if (bdrv_read(bs[bs_i], sector_num - bs_offset, buf, n) < 0)
error("error while reading");
/* NOTE: at the same time we convert, we do not write zero
sectors to have a chance to compress the image. Ideally, we
should add a specific call to have the info to go faster */
buf1 = buf;
while (n > 0) {
/* If the output image is being created as a copy on write image,
copy all sectors even the ones containing only NUL bytes,
because they may differ from the sectors in the base image. */
if (out_baseimg || is_allocated_sectors(buf1, n, &n1)) {
if (bdrv_write(out_bs, sector_num, buf1, n1) < 0)
error("error while writing");
}
sector_num += n1;
n -= n1;
buf1 += n1 * 512;
}
}
}
bdrv_delete(out_bs);
for (bs_i = 0; bs_i < bs_n; bs_i++)
bdrv_delete(bs[bs_i]);
free(bs);
return 0;
}
#ifdef _WIN32
static int64_t get_allocated_file_size(const char *filename)
{
typedef DWORD (WINAPI * get_compressed_t)(const char *filename, DWORD *high);
get_compressed_t get_compressed;
struct _stati64 st;
/* WinNT support GetCompressedFileSize to determine allocate size */
get_compressed = (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"), "GetCompressedFileSizeA");
if (get_compressed) {
DWORD high, low;
low = get_compressed(filename, &high);
if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR)
return (((int64_t) high) << 32) + low;
}
if (_stati64(filename, &st) < 0)
return -1;
return st.st_size;
}
#else
static int64_t get_allocated_file_size(const char *filename)
{
struct stat st;
if (stat(filename, &st) < 0)
return -1;
return (int64_t)st.st_blocks * 512;
}
#endif
static void dump_snapshots(BlockDriverState *bs)
{
QEMUSnapshotInfo *sn_tab, *sn;
int nb_sns, i;
char buf[256];
nb_sns = bdrv_snapshot_list(bs, &sn_tab);
if (nb_sns <= 0)
return;
printf("Snapshot list:\n");
printf("%s\n", bdrv_snapshot_dump(buf, sizeof(buf), NULL));
for(i = 0; i < nb_sns; i++) {
sn = &sn_tab[i];
printf("%s\n", bdrv_snapshot_dump(buf, sizeof(buf), sn));
}
qemu_free(sn_tab);
}
static int img_info(int argc, char **argv)
{
int c;
const char *filename, *fmt;
BlockDriver *drv;
BlockDriverState *bs;
char fmt_name[128], size_buf[128], dsize_buf[128];
uint64_t total_sectors;
int64_t allocated_size;
char backing_filename[1024];
char backing_filename2[1024];
BlockDriverInfo bdi;
fmt = NULL;
for(;;) {
c = getopt(argc, argv, "f:h");
if (c == -1)
break;
switch(c) {
case 'h':
help();
break;
case 'f':
fmt = optarg;
break;
}
}
if (optind >= argc)
help();
filename = argv[optind++];
bs = bdrv_new("");
if (!bs)
error("Not enough memory");
if (fmt) {
drv = bdrv_find_format(fmt);
if (!drv)
error("Unknown file format '%s'", fmt);
} else {
drv = NULL;
}
if (bdrv_open2(bs, filename, BRDV_O_FLAGS, drv) < 0) {
error("Could not open '%s'", filename);
}
bdrv_get_format(bs, fmt_name, sizeof(fmt_name));
bdrv_get_geometry(bs, &total_sectors);
get_human_readable_size(size_buf, sizeof(size_buf), total_sectors * 512);
allocated_size = get_allocated_file_size(filename);
if (allocated_size < 0)
snprintf(dsize_buf, sizeof(dsize_buf), "unavailable");
else
get_human_readable_size(dsize_buf, sizeof(dsize_buf),
allocated_size);
printf("image: %s\n"
"file format: %s\n"
"virtual size: %s (%" PRId64 " bytes)\n"
"disk size: %s\n",
filename, fmt_name, size_buf,
(total_sectors * 512),
dsize_buf);
if (bdrv_is_encrypted(bs))
printf("encrypted: yes\n");
if (bdrv_get_info(bs, &bdi) >= 0) {
if (bdi.cluster_size != 0)
printf("cluster_size: %d\n", bdi.cluster_size);
if (bdi.highest_alloc)
printf("highest_alloc: %" PRId64 "\n", bdi.highest_alloc);
if (bdi.num_free_bytes)
printf("num_free_bytes: %" PRId64 "\n", bdi.num_free_bytes);
}
bdrv_get_backing_filename(bs, backing_filename, sizeof(backing_filename));
if (backing_filename[0] != '\0') {
path_combine(backing_filename2, sizeof(backing_filename2),
filename, backing_filename);
printf("backing file: %s (actual path: %s)\n",
backing_filename,
backing_filename2);
}
dump_snapshots(bs);
bdrv_delete(bs);
return 0;
}
#define SNAPSHOT_LIST 1
#define SNAPSHOT_CREATE 2
#define SNAPSHOT_APPLY 3
#define SNAPSHOT_DELETE 4
static void img_snapshot(int argc, char **argv)
{
BlockDriverState *bs;
QEMUSnapshotInfo sn;
char *filename, *snapshot_name = NULL;
int c, ret;
int action = 0;
qemu_timeval tv;
/* Parse commandline parameters */
for(;;) {
c = getopt(argc, argv, "la:c:d:h");
if (c == -1)
break;
switch(c) {
case 'h':
help();
return;
case 'l':
if (action) {
help();
return;
}
action = SNAPSHOT_LIST;
break;
case 'a':
if (action) {
help();
return;
}
action = SNAPSHOT_APPLY;
snapshot_name = optarg;
break;
case 'c':
if (action) {
help();
return;
}
action = SNAPSHOT_CREATE;
snapshot_name = optarg;
break;
case 'd':
if (action) {
help();
return;
}
action = SNAPSHOT_DELETE;
snapshot_name = optarg;
break;
}
}
if (optind >= argc)
help();
filename = argv[optind++];
/* Open the image */
bs = bdrv_new("");
if (!bs)
error("Not enough memory");
if (bdrv_open2(bs, filename, 0, NULL) < 0) {
error("Could not open '%s'", filename);
}
/* Perform the requested action */
switch(action) {
case SNAPSHOT_LIST:
dump_snapshots(bs);
break;
case SNAPSHOT_CREATE:
memset(&sn, 0, sizeof(sn));
pstrcpy(sn.name, sizeof(sn.name), snapshot_name);
qemu_gettimeofday(&tv);
sn.date_sec = tv.tv_sec;
sn.date_nsec = tv.tv_usec * 1000;
ret = bdrv_snapshot_create(bs, &sn);
if (ret)
error("Could not create snapshot '%s': %d (%s)",
snapshot_name, ret, strerror(-ret));
break;
case SNAPSHOT_APPLY:
ret = bdrv_snapshot_goto(bs, snapshot_name);
if (ret)
error("Could not apply snapshot '%s': %d (%s)",
snapshot_name, ret, strerror(-ret));
break;
case SNAPSHOT_DELETE:
ret = bdrv_snapshot_delete(bs, snapshot_name);
if (ret)
error("Could not delete snapshot '%s': %d (%s)",
snapshot_name, ret, strerror(-ret));
break;
}
/* Cleanup */
bdrv_delete(bs);
}
int main(int argc, char **argv)
{
const char *cmd;
bdrv_init();
if (argc < 2)
help();
cmd = argv[1];
optind++;
if (!strcmp(cmd, "create")) {
img_create(argc, argv);
} else if (!strcmp(cmd, "commit")) {
img_commit(argc, argv);
} else if (!strcmp(cmd, "convert")) {
img_convert(argc, argv);
} else if (!strcmp(cmd, "info")) {
img_info(argc, argv);
} else if (!strcmp(cmd, "snapshot")) {
img_snapshot(argc, argv);
} else {
help();
}
return 0;
}