summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorRob Landley2006-05-25 23:02:40 +0000
committerRob Landley2006-05-25 23:02:40 +0000
commit399d2b5c24aaa059104a89058c7d4c8b97f41629 (patch)
tree1c6aed143c5dd2ff927190caf83b683c013028cb
parent69d863b6c609ac0523c546e408cc5d2063073425 (diff)
downloadbusybox-399d2b5c24aaa059104a89058c7d4c8b97f41629.zip
busybox-399d2b5c24aaa059104a89058c7d4c8b97f41629.tar.gz
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...)
-rw-r--r--coreutils/watch.c82
-rw-r--r--include/libbb.h2
-rw-r--r--libbb/xfuncs.c34
3 files changed, 57 insertions, 61 deletions
diff --git a/coreutils/watch.c b/coreutils/watch.c
index 9e0c54c..b783d34 100644
--- a/coreutils/watch.c
+++ b/coreutils/watch.c
@@ -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) {
+ char *thyme;
+ time_t t;
+
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");
- }
+ thyme = ctime(&t);
+ len = strlen(thyme);
+ if (len < width) header[width-len] = 0;
+
+ printf("\033[H\033[J%s %s\n", header, thyme);
- 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");
- }
+ waitpid(bb_xspawn(watched_argv),0,0);
+ sleep(period);
}
}
diff --git a/include/libbb.h b/include/libbb.h
index ca3afea..928e25d 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -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);
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index d3c9e41..2cfafb0 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -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