3 * Copyright (C) 2002 Simone Piccardi
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or (at
8 * your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 /*****************************************************************************
23 * An example for shared memory use: monitor a directory status,
24 * saving data in a shared memory segment. This version use POSIX
27 * Author: S. Piccardi Jan. 2003
29 *****************************************************************************/
30 #include <sys/types.h> /* primitive system data types */
31 #include <sys/stat.h> /* file characteristics constants and functions */
32 #include <dirent.h> /* directory operation constants and functions */
33 #include <stdlib.h> /* C standard library */
34 #include <unistd.h> /* unix standard library */
39 /* Help printing routine */
41 /* computation function for DirScan */
42 int ComputeValues(struct dirent * direntry);
43 void HandSIGTERM(int signo);
45 /* global variables for shared memory segment */
60 int main(int argc, char *argv[])
65 * Input section: decode command line parameters
68 opterr = 0; /* don't want writing to stderr */
69 while ( (i = getopt(argc, argv, "hp:")) != -1) {
74 case 'p': /* set pause (in sec.) */
75 pause = strtol(optarg, NULL, 10);
77 case 'h': /* help option */
78 printf("Wrong -h option use\n");
82 case '?': /* unrecognized options */
83 printf("Unrecognized options -%c\n",optopt);
85 default: /* should not reached */
89 /* ***********************************************************
91 * Options processing completed
95 * ***********************************************************/
96 if ((argc - optind) != 1) { /* There must be remaing parameters */
97 printf("Wrong number of arguments %d\n", argc - optind);
100 if (chdir(argv[1])) { /* chdir to be sure dir exist */
101 perror("Cannot find directory to monitor");
104 Signal(SIGTERM, HandSIGTERM); /* set handlers for termination */
105 Signal(SIGINT, HandSIGTERM);
106 Signal(SIGQUIT, HandSIGTERM);
107 key = ftok("~/gapil/sources/DirMonitor.c", 1); /* define a key, use dir */
108 shmid = shmget(key, 4096, IPC_CREAT|0666); /* get a shared memory */
110 perror("Cannot create shared memory");
113 if ( (shmptr = shmat(shmid, NULL, 0)) == NULL ) { /* attach to process */
114 perror("Cannot attach segment");
117 if ((mutex = MutexCreate(key)) == -1) { /* get a Mutex */
118 perror("Cannot create mutex");
121 /* main loop, monitor directory properties each 10 sec */
122 daemon(1, 0); /* demonize process, staying in monitored dir */
124 MutexLock(mutex); /* lock shared memory */
125 memset(shmptr, 0, sizeof(struct DirProp)); /* erase previous data */
126 DirScan(argv[1], ComputeValues); /* execute scan */
127 MutexUnlock(mutex); /* unlock shared memory */
128 sleep(pause); /* sleep until next watch */
132 * Routine to compute directory properties inside DirScan
134 int ComputeValues(struct dirent * direntry)
137 stat(direntry->d_name, &data); /* get stat data */
138 shmptr->tot_size += data.st_size;
140 if (S_ISREG(data.st_mode)) shmptr->tot_regular++;
141 if (S_ISFIFO(data.st_mode)) shmptr->tot_fifo++;
142 if (S_ISLNK(data.st_mode)) shmptr->tot_link++;
143 if (S_ISDIR(data.st_mode)) shmptr->tot_dir++;
144 if (S_ISBLK(data.st_mode)) shmptr->tot_block++;
145 if (S_ISCHR(data.st_mode)) shmptr->tot_char++;
146 if (S_ISSOCK(data.st_mode)) shmptr->tot_sock++;
150 * routine to print usage info and exit
153 printf("Program myls: list file in a directory \n");
155 printf(" DirMonitor [-h] [-p sec] dirname \n");
156 printf(" -h print this help\n");
157 printf(" -p sec set watch interval to sec seconds \n");
161 * Signal Handler to manage termination
163 void HandSIGTERM(int signo) {
165 debug("Terminated by %s\n", strsignal(signo));
167 perror("Error detaching shared memory");
170 if (shmctl(shmid, IPC_RMID, NULL)) {
171 perror("Cannot remove shared memory segment");