diff options
| author | christos <christos@NetBSD.org> | 2012-11-01 23:30:19 +0000 |
|---|---|---|
| committer | christos <christos@NetBSD.org> | 2012-11-01 23:30:19 +0000 |
| commit | d1b5215285d025c69b24abae3dcdaa8afaf0f796 (patch) | |
| tree | b92ec7b0a9c49d5c49da5fa54ead5d7ee029fb0c /usr.bin/flock | |
| parent | 291f566eaaa2e5b38deb579fa1716439eea35f1e (diff) | |
Add an flock program inspired by the linux one with the same name.
Diffstat (limited to 'usr.bin/flock')
| -rw-r--r-- | usr.bin/flock/Makefile | 8 | ||||
| -rw-r--r-- | usr.bin/flock/flock.1 | 99 | ||||
| -rw-r--r-- | usr.bin/flock/flock.c | 211 |
3 files changed, 318 insertions, 0 deletions
diff --git a/usr.bin/flock/Makefile b/usr.bin/flock/Makefile new file mode 100644 index 00000000000..ba91e5f790a --- /dev/null +++ b/usr.bin/flock/Makefile @@ -0,0 +1,8 @@ +# $NetBSD: Makefile,v 1.1 2012/11/01 23:30:19 christos Exp $ +# @(#)Makefile 8.1 (Berkeley) 6/6/93 + +PROG= flock +#LDADD+= -lutil +#DPADD+= ${LIBUTIL} + +.include <bsd.prog.mk> diff --git a/usr.bin/flock/flock.1 b/usr.bin/flock/flock.1 new file mode 100644 index 00000000000..5b95f85161f --- /dev/null +++ b/usr.bin/flock/flock.1 @@ -0,0 +1,99 @@ +.\" $NetBSD: flock.1,v 1.1 2012/11/01 23:30:19 christos Exp $ +.\" +.\" Copyright (c) 2012 The NetBSD Foundation, Inc. +.\" All rights reserved. +.\" +.\" This code is derived from software contributed to The NetBSD Foundation +.\" by Christos Zoulas. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS +.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS +.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +.\" POSSIBILITY OF SUCH DAMAGE. +.\" +.\" +.Dd November 1, 2012 +.Dt flock 1 +.Os +.Sh NAME +.Nm flock +.Nd Provide locking API for shell scripts +.Sh SYNOPSIS +.Nm +.Op Fl dnosxv +.Op Fl w Ar timeout +.Ar lockfile|lockdir +.Op Ar c +.Ar command +.Nm +.Op Fl dnusxv +.Op Fl w Ar timeout +.Ar lockfd +.Sh DESCRIPTION +The +.Nm +utility provides +.Xr flock 2 +access to the command line or scripts. +The first form locks a file or directory while the command provided is executed. +If the file or directory does not exist, then a file is created. +.Pp +The second form can use an arbitrary file descriptor that is provided from a +shell script for example: +.nf +( + flock -s 100 + # commands to be executed under the lock +) 100> /path/to/lockfile +.if +.Pp +The following options are available: +.Bl -tag -width "XXXXXXXXXXXXXXXXX" +.It Fl c Ar command +Pass a command to a the shell. +.It Fl d Fl Fl debug +Provide debugging output. +.It Fl s Fl Fl shared +Obtain a shared lock. +.It Fl e Fl x Fl Fl exclusive +Obtain an exclusive lock. +.It Fl u Fl Fl unlock +Unlock an existing lock. +This is available only for a file descriptor. +.It Fl n Fl Fl nb Fl Fl nonblock +Don't block and fail immediately if the lock could not be obtained. +.If Fl v Fl Fl verbose +On error print an explanation of the failure. +.It Fl w Fl Fl wait Fl Fl timeout Ar seconds +Fail if the lock could not be obtained after +.Ar seconds . +Seconds are truncated to integer values. +.It Fl o Fl Fl close +Close the file before executing the command. +This is useful if the child forks and should not be holding the lock. +.El +.Sh EXIT STATUS +.Ex -std +.Sh SEE ALSO +.Xr flock 2 +.Sh HISTORY +A +.Nm +utility appeared in +.Nx 7 diff --git a/usr.bin/flock/flock.c b/usr.bin/flock/flock.c new file mode 100644 index 00000000000..632a86e4d3f --- /dev/null +++ b/usr.bin/flock/flock.c @@ -0,0 +1,211 @@ +/* $NetBSD: flock.c,v 1.1 2012/11/01 23:30:19 christos Exp $ */ + +/*- + * Copyright (c) 2012 The NetBSD Foundation, Inc. + * All rights reserved. + * + * This code is derived from software contributed to The NetBSD Foundation + * by Christos Zoulas. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__RCSID("$NetBSD: flock.c,v 1.1 2012/11/01 23:30:19 christos Exp $"); + +#include <stdio.h> +#include <string.h> +#include <fcntl.h> +#include <stdlib.h> +#include <signal.h> +#include <unistd.h> +#include <err.h> +#include <errno.h> +#include <getopt.h> +#include <paths.h> + +struct option flock_longopts[] = { + { "debug", no_argument, 0, 'd' }, + { "help", no_argument, 0, 'h' }, + { "nonblock", no_argument, 0, 'n' }, + { "nb", no_argument, 0, 'n' }, + { "close", no_argument, 0, 'o' }, + { "shared", no_argument, 0, 's' }, + { "exclusive", no_argument, 0, 'x' }, + { "unlock", no_argument, 0, 'u' }, + { "verbose", no_argument, 0, 'v' }, + { "command", required_argument, 0, 'c' }, + { "wait", required_argument, 0, 'w' }, + { "timeout", required_argument, 0, 'w' }, + { NULL, 0, 0, 0 }, +}; + +static int verbose = 0; + +static __dead void usage(void) +{ + fprintf(stderr, "Usage: %s [-dnosxv] [-w <timeout>] file|directory [-c] " + "<command>\n\t%s [-dnusxv] [-w <timeout>] fd\n", getprogname(), + getprogname()); + exit(EXIT_FAILURE); +} + +static __dead void +sigalrm(int sig) +{ + if (verbose) { + errno = ETIMEDOUT; + errx(EXIT_FAILURE, ""); + } else + exit(EXIT_FAILURE); +} + +static const char * +lock2name(int l) +{ + static char buf[1024]; + int nb = l & LOCK_NB; + + l &= ~LOCK_NB; + if (nb) + strlcpy(buf, "LOCK_NB|", sizeof(buf)); + else + buf[0] = '\0'; + + switch (l) { + case LOCK_SH: + strlcat(buf, "LOCK_SH", sizeof(buf)); + return buf; + case LOCK_EX: + strlcat(buf, "LOCK_EX", sizeof(buf)); + return buf; + case LOCK_UN: + strlcat(buf, "LOCK_UN", sizeof(buf)); + return buf; + default: + snprintf(buf, sizeof(buf), "*%d*", l | nb); + return buf; + } +} + +int +main(int argc, char *argv[]) +{ + int c; + int lock = 0; + double timeout = 0; + int cls = 0; + int fd = -1; + int debug = 0; + char *command = NULL; + + setprogname(argv[0]); + + while ((c = getopt_long(argc, argv, "c:dnosxuw:", flock_longopts, NULL)) + != -1) + switch (c) { + case 'c': + command = optarg; + break; + case 'd': + debug++; + break; + case 'e': + case 'x': + lock |= LOCK_EX; + break; + case 'n': + lock |= LOCK_NB; + break; + case 's': + lock |= LOCK_SH; + break; + case 'u': + lock |= LOCK_UN; + break; + case 'w': + timeout = strtod(optarg, NULL); + break; + case 'v': + verbose = 1; + break; + case 'o': + cls = 1; + break; + default: + usage(); + } + + argc -= optind; + argv += optind; + + if (command) { + if (lock == LOCK_UN) + usage(); + if ((fd = open(argv[0], O_RDONLY)) == -1) { + if (errno != ENOENT || + (fd = open(argv[0], O_RDWR|O_CREAT, 0600)) == -1) + err(EXIT_FAILURE, "Cannot open `%s'", argv[0]); + } + if (debug) + fprintf(stderr, "file %s lock %s command %s\n", + argv[0], lock2name(lock), command); + + + } else { + if (cls) + usage(); + fd = strtol(argv[0], NULL, 0); // XXX: error checking + if (debug) + fprintf(stderr, "descriptor %s lock %s\n", + argv[0], lock2name(lock)); + } + + if (timeout) { + signal(SIGALRM, sigalrm); + alarm((int)timeout); // XXX: User timer_create() + if (debug) + fprintf(stderr, "alarm %d\n", (int)timeout); + } + + if (flock(fd, lock) == -1) { + if (verbose) + err(EXIT_FAILURE, "flock(%d, %s)", fd, lock2name(lock)); + else + return EXIT_FAILURE; + } + + if (timeout) + alarm(0); + + if (cls) + (void)close(fd); + + if (command == NULL) + return 0; + if (debug) + fprintf(stderr, "execute %s -c '%s'\n", _PATH_BSHELL, command); + execlp(_PATH_BSHELL, "sh", "-c", command, NULL); + err(EXIT_FAILURE, "exec %s -c '%s'", _PATH_BSHELL, command); + return 0; +} |
