diff -urN busybox.old/include/applets.h busybox.dev/include/applets.h --- busybox.old/include/applets.h 2006-04-05 01:06:29.000000000 +0200 +++ busybox.dev/include/applets.h 2006-04-05 01:19:09.000000000 +0200 @@ -167,6 +167,7 @@ USE_LN(APPLET(ln, ln_main, _BB_DIR_BIN, _BB_SUID_NEVER)) USE_LOADFONT(APPLET(loadfont, loadfont_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)) USE_LOADKMAP(APPLET(loadkmap, loadkmap_main, _BB_DIR_SBIN, _BB_SUID_NEVER)) +USE_LOCK(APPLET_NOUSAGE(lock, lock_main, _BB_DIR_BIN, _BB_SUID_NEVER)) USE_LOGGER(APPLET(logger, logger_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)) USE_LOGIN(APPLET(login, login_main, _BB_DIR_BIN, _BB_SUID_ALWAYS)) USE_LOGNAME(APPLET(logname, logname_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)) diff -urN busybox.old/miscutils/Config.in busybox.dev/miscutils/Config.in --- busybox.old/miscutils/Config.in 2006-03-22 22:16:24.000000000 +0100 +++ busybox.dev/miscutils/Config.in 2006-04-05 01:07:12.000000000 +0200 @@ -209,6 +209,12 @@ Enables the 'hdparm -d' option to get/set using_dma flag. This is dangerous stuff, so you should probably say N. +config CONFIG_LOCK + bool "lock" + default y + help + Small utility for using locks in scripts + config CONFIG_MAKEDEVS bool "makedevs" default n diff -urN busybox.old/miscutils/Makefile.in busybox.dev/miscutils/Makefile.in --- busybox.old/miscutils/Makefile.in 2006-03-22 22:16:24.000000000 +0100 +++ busybox.dev/miscutils/Makefile.in 2006-04-05 01:10:50.000000000 +0200 @@ -20,6 +20,7 @@ MISCUTILS-$(CONFIG_EJECT) += eject.o MISCUTILS-$(CONFIG_HDPARM) += hdparm.o MISCUTILS-$(CONFIG_LAST) += last.o +MISCUTILS-$(CONFIG_LOCK) += lock.o MISCUTILS-${CONFIG_LESS} += less.o MISCUTILS-$(CONFIG_MAKEDEVS) += makedevs.o MISCUTILS-$(CONFIG_MOUNTPOINT) += mountpoint.o diff -urN busybox.old/miscutils/lock.c busybox.dev/miscutils/lock.c --- busybox.old/miscutils/lock.c 1970-01-01 01:00:00.000000000 +0100 +++ busybox.dev/miscutils/lock.c 2006-04-05 01:07:12.000000000 +0200 @@ -0,0 +1,128 @@ +#include <sys/types.h> +#include <sys/file.h> +#include <sys/stat.h> +#include <signal.h> +#include <fcntl.h> +#include <unistd.h> +#include <stdio.h> +#include "busybox.h" + +static int unlock = 0; +static int shared = 0; +static int waitonly = 0; +static int fd; +static char *file; + +static void usage(char *name) +{ + fprintf(stderr, "Usage: %s [-suw] <filename>\n" + " -s Use shared locking\n" + " -u Unlock\n" + " -w Wait for the lock to become free, don't acquire lock\n" + "\n", name); + exit(1); +} + +static void exit_unlock(int sig) +{ + flock(fd, LOCK_UN); + unlink(file); + exit(0); +} + +static int do_unlock(void) +{ + FILE *f; + int i; + + if ((f = fopen(file, "r")) == NULL) + return 0; + + fscanf(f, "%d", &i); + if (i > 0) + kill(i, SIGTERM); + + fclose(f); + + return 0; +} + +static int do_lock(void) +{ + int pid; + char pidstr[8]; + + if ((fd = open(file, O_RDWR | O_CREAT, 0700)) < 0) { + fprintf(stderr, "Can't open %s\n", file); + return 1; + } + + if (flock(fd, (shared ? LOCK_SH : LOCK_EX)) < 0) { + fprintf(stderr, "Can't lock %s\n", file); + return 1; + } + + pid = fork(); + + if (pid < 0) + return -1; + + if (pid == 0) { + signal(SIGKILL, exit_unlock); + signal(SIGTERM, exit_unlock); + signal(SIGINT, exit_unlock); + if (waitonly) + exit_unlock(0); + else + while (1) + sleep(1); + } else { + if (!waitonly) { + lseek(fd, 0, SEEK_SET); + ftruncate(fd, 0); + sprintf(pidstr, "%d\n", pid); + write(fd, pidstr, strlen(pidstr)); + close(fd); + } + + return 0; + } +} + +#ifndef CONFIG_LOCK +int main(int argc, char **argv) +#else +int lock_main(int argc, char **argv) +#endif +{ + char **args = &argv[1]; + int c = argc - 1; + + while ((*args != NULL) && (*args)[0] == '-') { + char *ch = *args; + while (*(++ch) > 0) { + switch(*ch) { + case 'w': + waitonly = 1; + break; + case 's': + shared = 1; + break; + case 'u': + unlock = 1; + break; + } + } + c--; + args++; + } + + if (c != 1) + usage(argv[0]); + + file = *args; + if (unlock) + return do_unlock(); + else + return do_lock(); +}