Rich Felker suggested removing dprintf() from watch, and one thing led to
another... This adds bb_xspawn() support, which does vfork/exec. (I don't know why using a static instead of a local adds ~40 bytes, but using the local doesn't work...)
This commit is contained in:
Rob Landley
parent
69d863b6c6
commit
399d2b5c24
|
|
@ -4,20 +4,7 @@
|
|||
*
|
||||
* Copyright (C) 2001 by Michael Habermann <mhabermann@gmx.de>
|
||||
*
|
||||
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
||||
*
|
||||
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
|
||||
*/
|
||||
|
||||
/* BB_AUDIT SUSv3 N/A */
|
||||
|
|
@ -41,23 +28,18 @@
|
|||
|
||||
int watch_main(int argc, char **argv)
|
||||
{
|
||||
const int header_len = 40;
|
||||
time_t t;
|
||||
pid_t pid;
|
||||
int width, len;
|
||||
unsigned period = 2;
|
||||
int old_stdout;
|
||||
int len, len2;
|
||||
char **watched_argv;
|
||||
char header[header_len + 1];
|
||||
char **watched_argv, *header;
|
||||
|
||||
if (argc < 2) {
|
||||
bb_show_usage();
|
||||
}
|
||||
if (argc < 2) bb_show_usage();
|
||||
|
||||
get_terminal_width_height(1, &width, 0);
|
||||
header = xzalloc(width--);
|
||||
|
||||
/* don't use getopt, because it permutes the arguments */
|
||||
++argv;
|
||||
if ((argc > 3) && !strcmp(*argv, "-n")
|
||||
) {
|
||||
if ((argc > 3) && !strcmp(*argv, "-n")) {
|
||||
period = bb_xgetularg10_bnd(argv[1], 1, UINT_MAX);
|
||||
argv += 2;
|
||||
}
|
||||
|
|
@ -65,44 +47,22 @@ int watch_main(int argc, char **argv)
|
|||
|
||||
/* create header */
|
||||
|
||||
len = snprintf(header, header_len, "Every %ds:", period);
|
||||
/* Don't bother checking for len < 0, as it should never happen.
|
||||
* But, just to be prepared... */
|
||||
assert(len >= 0);
|
||||
do {
|
||||
len2 = strlen(*argv);
|
||||
if (len + len2 >= header_len-1) {
|
||||
break;
|
||||
}
|
||||
header[len] = ' ';
|
||||
memcpy(header+len+1, *argv, len2);
|
||||
len += len2+1;
|
||||
} while (*++argv);
|
||||
|
||||
header[len] = 0;
|
||||
|
||||
/* thanks to lye, who showed me how to redirect stdin/stdout */
|
||||
old_stdout = dup(STDOUT_FILENO);
|
||||
len = snprintf(header, width, "Every %ds:", period);
|
||||
while (*argv && len<width)
|
||||
snprintf(header+len, width-len, " %s", *(argv++));
|
||||
|
||||
while (1) {
|
||||
time(&t);
|
||||
/* Use dprintf to avoid fflush()ing stdout. */
|
||||
if (dprintf(1, "\033[H\033[J%-*s%s\n", header_len, header, ctime(&t)) < 0) {
|
||||
bb_perror_msg_and_die("printf");
|
||||
}
|
||||
char *thyme;
|
||||
time_t t;
|
||||
|
||||
pid = vfork(); /* vfork, because of ucLinux */
|
||||
if (pid > 0) {
|
||||
//parent
|
||||
wait(0);
|
||||
sleep(period);
|
||||
} else if (0 == pid) {
|
||||
//child
|
||||
dup2(old_stdout, STDOUT_FILENO);
|
||||
execvp(*watched_argv, watched_argv);
|
||||
bb_perror_msg_and_die("%s", *watched_argv);
|
||||
} else {
|
||||
bb_perror_msg_and_die("vfork");
|
||||
}
|
||||
time(&t);
|
||||
thyme = ctime(&t);
|
||||
len = strlen(thyme);
|
||||
if (len < width) header[width-len] = 0;
|
||||
|
||||
printf("\033[H\033[J%s %s\n", header, thyme);
|
||||
|
||||
waitpid(bb_xspawn(watched_argv),0,0);
|
||||
sleep(period);
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -146,6 +146,8 @@ extern void bb_fflush_stdout_and_exit(int retval) ATTRIBUTE_NORETURN;
|
|||
|
||||
extern void xstat(const char *filename, struct stat *buf);
|
||||
extern int bb_xsocket(int domain, int type, int protocol);
|
||||
extern pid_t bb_spawn(char **argv);
|
||||
extern pid_t bb_xspawn(char **argv);
|
||||
extern void bb_xdaemon(int nochdir, int noclose);
|
||||
extern void bb_xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen);
|
||||
extern void bb_xlisten(int s, int backlog);
|
||||
|
|
|
|||
|
|
@ -182,3 +182,37 @@ void bb_xfflush_stdout(void)
|
|||
}
|
||||
}
|
||||
#endif
|
||||
|
||||
#ifdef L_spawn
|
||||
// This does a fork/exec in one call, using vfork().
|
||||
pid_t bb_spawn(char **argv)
|
||||
{
|
||||
static int failed;
|
||||
pid_t pid;
|
||||
|
||||
// Be nice to nommu machines.
|
||||
failed = 0;
|
||||
pid = vfork();
|
||||
if (pid < 0) return pid;
|
||||
if (!pid) {
|
||||
execvp(*argv, argv);
|
||||
|
||||
// We're sharing a stack with blocked parent, let parent know we failed
|
||||
// and then exit to unblock parent (but don't run atexit() stuff, which
|
||||
// would screw up parent.)
|
||||
|
||||
failed = -1;
|
||||
_exit(0);
|
||||
}
|
||||
return failed ? failed : pid;
|
||||
}
|
||||
#endif
|
||||
|
||||
#ifdef L_xspawn
|
||||
pid_t bb_xspawn(char **argv)
|
||||
{
|
||||
pid_t pid = bb_spawn(argv);
|
||||
if (pid < 0) bb_perror_msg_and_die("%s", *argv);
|
||||
return pid;
|
||||
}
|
||||
#endif
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user