+++ /dev/null
-/* Flock.c
- *
- * Copyright (C) 2001 Simone Piccardi
- *
- * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-/*****************************************************************************
- *
- * Program Flock.c:
- * Program to test file locking
- *
- * Author: Simone Piccardi
- * Nov. 2002
- *
- * Usage: flock -h give all info's
- *
- * $Id: Flock.c,v 1.3 2002/11/18 23:54:01 piccardi Exp $
- *
- *****************************************************************************/
-/*
- * Include needed headers
- */
-#include <errno.h> /* error definitions and routines */
-#include <stdlib.h> /* C standard library */
-#include <unistd.h> /* unix standard library */
-#include <stdio.h> /* standard I/O library */
-#include <string.h> /* string functions */
-#include <fcntl.h> /* string functions */
-/* user defined header */
-#include "macros.h" /* some useful macros */
-
-/* Help printing routine */
-void usage(void);
-
-int main(int argc, char *argv[])
-{
-/*
- * Variables definition
- */
- int type = F_UNLCK; /* lock type: default to unlock (invalid) */
- off_t start = 0; /* start of the locked region: default to 0 */
- off_t len = 0; /* length of the locked region: default to 0 */
- int fd, res, i; /* internal variables */
- int bsd = 0; /* semantic type: default to POSIX */
- int cmd = F_SETLK; /* lock command: default to non-blocking */
- struct flock lock; /* file lock structure */
- /*
- * Input section: decode command line parameters
- * Use getopt function
- */
- opterr = 0; /* don't want writing to stderr */
- while ( (i = getopt(argc, argv, "hs:l:wrbf")) != -1) {
- switch (i) {
- /*
- * Handling options
- */
- case 'h': /* help option */
- printf("Wrong -h option use\n");
- usage();
- return -1;
- break;
- case 's': /* take start point of the lock */
- start = strtol(optarg, NULL, 10); /* convert input */
- break;
- case 'l': /* take length of the lock */
- len = strtol(optarg, NULL, 10); /* convert input */
- break;
- case 'w': /* set type to write lock */
- type = F_WRLCK;
- break;
- case 'r': /* set type to read lock */
- type = F_RDLCK;
- break;
- case 'b': /* set lock to blocking */
- cmd = F_SETLKW;
- break;
- case 'f': /* enable BSD semantic */
- bsd = 1;
- break;
- case '?': /* unrecognized options */
- printf("Unrecognized options -%c\n",optopt);
- usage();
- default: /* should not reached */
- usage();
- }
- }
- /* ***********************************************************
- *
- * Options processing completed
- *
- * Main code beginning
- *
- * ***********************************************************/
- if ((argc - optind) != 1) { /* There must be remaing parameters */
- printf("Wrong number of arguments %d\n", argc - optind);
- usage();
- }
- if (type == F_UNLCK) { /* There must be a -w or -r option set */
- printf("You should set a read or a write lock\n");
- usage();
- }
- fd = open(argv[optind], O_RDONLY); /* open the file to be locked */
- if (fd < 0) { /* on error exit */
- perror("Wrong filename");
- exit(1);
- }
- /* do lock */
- if (bsd) { /* if BSD locking */
- /* rewrite cmd for suitables flock operation values */
- if (cmd == F_SETLK) { /* if no-blocking */
- cmd = LOCK_NB; /* set the value for flock operation */
- } else { /* else */
- cmd = 0; /* default is null */
- }
- if (type == F_RDLCK) cmd |= LOCK_SH; /* set for shared lock */
- if (type == F_WRLCK) cmd |= LOCK_EX; /* set for exclusive lock */
- res = flock(fd, cmd); /* esecute lock */
- } else { /* if POSIX locking */
- /* setting flock structure */
- lock.l_type = type; /* set type: read or write */
- lock.l_whence = SEEK_SET; /* start from the beginning of the file */
- lock.l_start = start; /* set the start of the locked region */
- lock.l_len = len; /* set the length of the locked region */
- res = fcntl(fd, cmd, &lock); /* do lock */
- }
- /* check lock results */
- if (res) { /* on error exit */
- perror("Failed lock");
- exit(1);
- } else { /* else write message */
- printf("Lock acquired\n");
- }
- pause(); /* stop the process, use a signal to exit */
- return 0;
-}
-/*
- * routine to print usage info and exit
- */
-void usage(void) {
- printf("Program flock: lock a region of a file \n");
- printf("Usage:\n");
- printf(" forktest [-h] [-s start] [-l len] [-w|-r] filename \n");
- printf(" -h print this help\n");
- printf(" -s start region starting byte\n");
- printf(" -l len region length (0 means all file)\n");
- printf(" -w write lock\n");
- printf(" -r read lock\n");
- printf(" -b block when locking impossible\n");
- printf(" -f enable BSD semantic\n");
- exit(1);
-}
projects / gapil.git / blobdiff