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/* guestfish - the filesystem interactive shell
* Copyright (C) 2009-2012 Red Hat Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <inttypes.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <assert.h>
#include "fish.h"
static char *generate_random_name (const char *filename);
/* guestfish edit command, suggested by Ján Ondrej, implemented by RWMJ */
int
run_edit (const char *cmd, size_t argc, char *argv[])
{
TMP_TEMPLATE_ON_STACK (filename);
char buf[256];
const char *editor;
char *remotefilename, *newname;
struct stat oldstat, newstat;
int r, fd;
if (argc != 1) {
fprintf (stderr, _("use '%s filename' to edit a file\n"), cmd);
goto error0;
}
/* Choose an editor. */
if (STRCASEEQ (cmd, "vi"))
editor = "vi";
else if (STRCASEEQ (cmd, "emacs"))
editor = "emacs -nw";
else {
editor = getenv ("EDITOR");
if (editor == NULL)
editor = "vi"; /* could be cruel here and choose ed(1) */
}
/* Handle 'win:...' prefix. */
remotefilename = win_prefix (argv[0]);
if (remotefilename == NULL)
goto error0;
/* Download the file and write it to a temporary. */
fd = mkstemp (filename);
if (fd == -1) {
perror ("mkstemp");
goto error1;
}
snprintf (buf, sizeof buf, "/dev/fd/%d", fd);
if (guestfs_download (g, remotefilename, buf) == -1) {
close (fd);
goto error2;
}
if (close (fd) == -1) {
perror (filename);
goto error2;
}
/* Get the old stat. */
if (stat (filename, &oldstat) == -1) {
perror (filename);
goto error2;
}
/* Edit it. */
/* XXX Safe? */
snprintf (buf, sizeof buf, "%s %s", editor, filename);
r = system (buf);
if (r != 0) {
perror (buf);
goto error2;
}
/* Get the new stat. */
if (stat (filename, &newstat) == -1) {
perror (filename);
goto error2;
}
/* Changed? */
if (oldstat.st_ctime == newstat.st_ctime &&
oldstat.st_size == newstat.st_size) {
unlink (filename);
free (remotefilename);
return 0;
}
/* Upload to a new file in the same directory, so if it fails we
* don't end up with a partially written file. Give the new file
* a completely random name so we have only a tiny chance of
* overwriting some existing file.
*/
newname = generate_random_name (remotefilename);
if (!newname)
goto error2;
/* Write new content. */
if (guestfs_upload (g, filename, newname) == -1)
goto error3;
if (guestfs_mv (g, newname, remotefilename) == -1)
goto error3;
free (newname);
unlink (filename);
free (remotefilename);
return 0;
error3:
free (newname);
error2:
unlink (filename);
error1:
free (remotefilename);
error0:
return -1;
}
static char
random_char (void)
{
char c[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
return c[random () % (sizeof c - 1)];
}
static char *
generate_random_name (const char *filename)
{
char *ret, *p;
size_t i;
ret = malloc (strlen (filename) + 16);
if (!ret) {
perror ("malloc");
return NULL;
}
strcpy (ret, filename);
p = strrchr (ret, '/');
assert (p);
p++;
/* Because of "+ 16" above, there should be enough space in the
* output buffer to write 8 random characters here.
*/
for (i = 0; i < 8; ++i)
*p++ = random_char ();
*p++ = '\0';
return ret; /* caller will free */
}
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