static int
write_or_append (guestfs_h *g, const char *path,
const char *content, size_t size,
int append)
{
CLEANUP_UNLINK_FREE char *tmpfile = NULL;
int fd = -1;
int64_t filesize;
/* If the content is small enough, use guestfs_internal_write{,_append}
* since that call is more efficient.
*/
if (size <= 2*1024*1024)
return
(!append ? guestfs_internal_write : guestfs_internal_write_append)
(g, path, content, size);
if (guestfs_int_lazy_make_tmpdir (g) == -1)
goto err;
/* Write the content out to a temporary file. */
tmpfile = safe_asprintf (g, "%s/write%d", g->tmpdir, ++g->unique);
fd = open (tmpfile, O_WRONLY|O_CREAT|O_NOCTTY|O_CLOEXEC, 0600);
if (fd == -1) {
perrorf (g, "open: %s", tmpfile);
goto err;
}
if (full_write (fd, content, size) != size) {
perrorf (g, "write: %s", tmpfile);
goto err;
}
if (close (fd) == -1) {
perrorf (g, "close: %s", tmpfile);
goto err;
}
fd = -1;
if (!append) {
if (guestfs_upload (g, tmpfile, path) == -1)
goto err;
}
else {
/* XXX Should have an 'upload-append' call to make this atomic. */
filesize = guestfs_filesize (g, path);
if (filesize == -1)
goto err;
if (guestfs_upload_offset (g, tmpfile, path, filesize) == -1)
goto err;
}
return 0;
err:
if (fd >= 0)
close (fd);
return -1;
}
int
run_hexedit (const char *cmd, size_t argc, char *argv[])
{
if (argc < 1 || argc > 3) {
fprintf (stderr, _("hexedit (device|filename) [max | start max]\n"));
return -1;
}
const char *filename = argv[0];
off_t size = get_size (filename);
if (size == -1)
return -1;
if (size == 0) {
fprintf (stderr,
_("hexedit: %s is a zero length file or device\n"), filename);
return -1;
}
off_t start;
off_t max;
if (argc == 1) { /* hexedit device */
/* Check we're not going to download a huge file. */
if (size > MAX_DOWNLOAD_SIZE) {
fprintf (stderr,
_("hexedit: %s is larger than %s. You must supply a limit using\n"
" 'hexedit %s <max>' (eg. 'hexedit %s 1M') or a range using\n"
" 'hexedit %s <start> <max>'.\n"),
filename, MAX_DOWNLOAD_SIZE_TEXT,
filename, filename,
filename);
return -1;
}
start = 0;
max = size;
}
else {
if (argc == 3) { /* hexedit device start max */
if (parse_size (argv[1], &start) == -1)
return -1;
if (parse_size (argv[2], &max) == -1)
return -1;
} else { /* hexedit device max */
start = 0;
if (parse_size (argv[1], &max) == -1)
return -1;
}
if (start + max > size)
max = size - start;
}
if (max <= 0) {
fprintf (stderr, _("hexedit: invalid range\n"));
return -1;
}
/* Download the requested range from the remote file|device into a
* local temporary file.
*/
const char *editor;
int r;
struct stat oldstat, newstat;
char tmpfd[sizeof "/dev/fd/" + 3 * sizeof (int)];
CLEANUP_FREE char *editcmd = NULL;
CLEANUP_FREE char *tmpdir = guestfs_get_tmpdir (g), *tmp = NULL;
if (asprintf (&tmp, "%s/guestfishXXXXXX", tmpdir) == -1) {
perror ("asprintf");
return -1;
}
int fd = mkstemp (tmp);
if (fd == -1) {
perror ("mkstemp");
return -1;
}
/* Choose an editor. */
editor = getenv ("HEXEDITOR");
if (editor == NULL)
editor = "hexedit";
snprintf (tmpfd, sizeof tmpfd, "/dev/fd/%d", fd);
if (guestfs_download_offset (g, filename, tmpfd, start, max) == -1) {
unlink (tmp);
close (fd);
return -1;
}
if (close (fd) == -1) {
unlink (tmp);
return -1;
}
/* Get the old stat. */
if (stat (tmp, &oldstat) == -1) {
perror (tmp);
unlink (tmp);
return -1;
}
/* Edit it. */
if (asprintf (&editcmd, "%s %s", editor, tmp) == -1) {
perror ("asprintf");
return -1;
}
r = system (editcmd);
if (r != 0) {
perror (editcmd);
unlink (tmp);
return -1;
}
/* Get the new stat. */
if (stat (tmp, &newstat) == -1) {
perror (tmp);
unlink (tmp);
return -1;
}
/* Changed? */
if (oldstat.st_ctime == newstat.st_ctime &&
oldstat.st_size == newstat.st_size) {
unlink (tmp);
return 0;
}
/* Write new content. */
if (guestfs_upload_offset (g, tmp, filename, start) == -1) {
unlink (tmp);
return -1;
}
unlink (tmp);
return 0;
}
