/* vim: set ts=4 sts=4 sw=4 noet : */
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#include<stdio.h>
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#include<stdlib.h>
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#include "general.h"
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#include<stdarg.h>
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#include <sys/time.h>
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#include <unistd.h>
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#include <time.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <string.h>
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ts_uint ts_fprintf(FILE *fd, char *fmt, ...){
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if(quiet) return TS_SUCCESS;
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va_list ap;
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va_start(ap,fmt);
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char tmbuf[255];
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struct timeval now;
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gettimeofday(&now, 0);
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strftime(tmbuf, sizeof tmbuf, "%Y-%m-%d %H:%M:%S", localtime(&now.tv_sec));
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fprintf(fd, "[%s] ",tmbuf);
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vfprintf(fd, fmt, ap); /* Call vfprintf */
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va_end(ap); /* Cleanup the va_list */
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return TS_SUCCESS;
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}
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void err(char *text){
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ts_fprintf(stderr,"Err: %s\n", text);
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}
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void fatal(char *text, ts_int errcode){
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ts_fprintf(stderr,"Fatal: %s. TERMINATED!\n", text);
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exit(errcode);
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}
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/* Open/create the file named in 'pidFile', lock it, optionally set the
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close-on-exec flag for the file descriptor, write our PID into the file,
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and (in case the caller is interested) return the file descriptor
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referring to the locked file. The caller is responsible for deleting
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'pidFile' file (just) before process termination. 'progName' should be the
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name of the calling program (i.e., argv[0] or similar), and is used only for
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diagnostic messages. If we can't open 'pidFile', or we encounter some other
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error, then we print an appropriate diagnostic and terminate. */
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/*
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This is filelock/create_pid_file.c (Listing 55-4, page 1143), an example program file from the book, The Linux Programming Interface.
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The source code file is copyright 2010, Michael Kerrisk, and is licensed under the GNU Lesser General Public License, version 3.
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*/
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#define BUF_SIZE 100
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int createPidFile(const char *progName, const char *pidFile, int flags)
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{
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int fd;
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char buf[BUF_SIZE];
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fd = open(pidFile, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
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if (fd == -1){
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ts_fprintf(stderr,"Could not open PID file %s", pidFile);
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fatal("Cannot continue (1)",1);
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}
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if (flags & CPF_CLOEXEC) {
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/* Set the close-on-exec file descriptor flag */
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/* Instead of the following steps, we could (on Linux) have opened the
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file with O_CLOEXEC flag. However, not all systems support open()
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O_CLOEXEC (which was standardized only in SUSv4), so instead we use
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fcntl() to set the close-on-exec flag after opening the file */
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flags = fcntl(fd, F_GETFD); /* Fetch flags */
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if (flags == -1){
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ts_fprintf(stderr,"Could not get flags for PID file %s", pidFile);
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fatal("Cannot continue (2)",1);
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}
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flags |= FD_CLOEXEC; /* Turn on FD_CLOEXEC */
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if (fcntl(fd, F_SETFD, flags) == -1) /* Update flags */
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ts_fprintf(stderr,"Could not set flags for PID file %s", pidFile);
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fatal("Cannot continue (3)",1);
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}
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if (lockRegion(fd, F_WRLCK, SEEK_SET, 0, 0) == -1) {
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if (errno == EAGAIN || errno == EACCES){
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ts_fprintf(stderr,"PID file '%s' is locked; probably "
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"'%s' is already running", pidFile, progName);
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fatal("Cannot continue (4)",1);
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}
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else{
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ts_fprintf(stderr,"Unable to lock PID file '%s'", pidFile);
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fatal("Cannot continue (5)",1);
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}
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}
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if (ftruncate(fd, 0) == -1){
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ts_fprintf(stderr,"Could not truncate PID file '%s'", pidFile);
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fatal("Cannot continue (6)",1);
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}
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snprintf(buf, BUF_SIZE, "%ld\n", (long) getpid());
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if (write(fd, buf, strlen(buf)) != strlen(buf)){
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ts_fprintf(stderr,"Writing to PID file '%s'", pidFile);
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fatal("Cannot continue (7)",1);
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}
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return fd;
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}
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/* Lock a file region (private; public interfaces below) */
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static int
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lockReg(int fd, int cmd, int type, int whence, int start, off_t len)
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{
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struct flock fl;
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fl.l_type = type;
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fl.l_whence = whence;
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fl.l_start = start;
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fl.l_len = len;
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return fcntl(fd, cmd, &fl);
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}
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int /* Lock a file region using nonblocking F_SETLK */
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lockRegion(int fd, int type, int whence, int start, int len)
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{
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return lockReg(fd, F_SETLK, type, whence, start, len);
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}
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