/* The "help" command. This used to just list all commands, but
* that's not very useful. Instead display some useful
* context-sensitive help. This could be improved if we knew how many
* drives had been added already, and whether anything was mounted.
*/
void
display_help (void)
{
if (guestfs_is_config (g))
printf (_(
"Add disk images to examine using the -a or -d options, or the 'add' command.\n"
"Or create a new disk image using -N, or the 'alloc' or 'sparse' commands.\n"
"Once you have done this, use the 'run' command.\n"
));
else
printf (_(
"Find out what filesystems are available using 'list-filesystems' and then\n"
"mount them to examine or modify the contents using 'mount-ro' or\n"
"'mount'.\n"
));
printf ("\n");
printf (_(
"For more information about a command, use 'help cmd'.\n"
"\n"
"To read the manual, type 'man'.\n"
));
printf ("\n");
}
/* This is the underlying allocation function. It's called from
* a few other places in guestfish.
*/
int
alloc_disk (const char *filename, const char *size_str, int add, int sparse)
{
off_t size;
int fd;
char c = 0;
if (parse_size (size_str, &size) == -1)
return -1;
if (!guestfs_is_config (g)) {
fprintf (stderr, _("can't allocate or add disks after launching\n"));
return -1;
}
fd = open (filename, O_WRONLY|O_CREAT|O_NOCTTY|O_TRUNC, 0666);
if (fd == -1) {
perror (filename);
return -1;
}
if (!sparse) { /* Not sparse */
#ifdef HAVE_POSIX_FALLOCATE
int err = posix_fallocate (fd, 0, size);
if (err != 0) {
errno = err;
perror ("fallocate");
close (fd);
unlink (filename);
return -1;
}
#else
/* Slow emulation of posix_fallocate on platforms which don't have it. */
char buffer[BUFSIZ];
memset (buffer, 0, sizeof buffer);
size_t remaining = size;
while (remaining > 0) {
size_t n = remaining > sizeof buffer ? sizeof buffer : remaining;
ssize_t r = write (fd, buffer, n);
if (r == -1) {
perror ("write");
close (fd);
unlink (filename);
return -1;
}
remaining -= r;
}
#endif
} else { /* Sparse */
if (lseek (fd, size-1, SEEK_SET) == (off_t) -1) {
perror ("lseek");
close (fd);
unlink (filename);
return -1;
}
if (write (fd, &c, 1) != 1) {
perror ("write");
close (fd);
unlink (filename);
return -1;
}
}
if (close (fd) == -1) {
perror (filename);
unlink (filename);
return -1;
}
if (add) {
if (guestfs_add_drive_opts (g, filename,
GUESTFS_ADD_DRIVE_OPTS_FORMAT, "raw",
-1) == -1) {
unlink (filename);
return -1;
}
}
return 0;
}
