/***************************************************
* Creat : 2001. 02. 10 (programed by Cori-Young)
* Site: http://www.byoneself.co.kr
* Update :
***************************************************/
#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <time.h>
static void do_shmctl();
extern void exit();
extern void perror();
main()
{
int cmd;
int shmid;
struct shmid_ds shmid_ds;
(void) fprintf(stderr, "All numeric input is expected to follow C conventions:n");
(void) fprintf(stderr, "t0x... is interpreted as hexadecimal,n");
(void) fprintf(stderr, "t0... is interpreted as octal,n");
(void) fprintf(stderr, "totherwise, decimal.n");
/* Get shmid and cmd. */
(void) fprintf(stderr,"Enter the shmid for the desired segment: ");
(void) scanf("%i", &shmid);
(void) fprintf(stderr, "Valid shmctl cmd values are:n");
(void) fprintf(stderr, "tIPC_RMID =t%dn", IPC_RMID);
(void) fprintf(stderr, "tIPC_SET =t%dn", IPC_SET);
(void) fprintf(stderr, "tIPC_STAT =t%dn", IPC_STAT);
(void) fprintf(stderr, "tSHM_LOCK =t%dn", SHM_LOCK);
(void) fprintf(stderr, "tSHM_UNLOCK =t%dn", SHM_UNLOCK);
(void) fprintf(stderr, "Enter the desired cmd value: ");
(void) scanf("%i", &cmd);
switch (cmd) {
case IPC_STAT:
/* Get shared memory segment status. */
break;
case IPC_SET:
/* Set owner UID and GID and permissions. */
/* Get and print current values. */
do_shmctl(shmid, IPC_STAT, &shmid_ds);
/* Set UID, GID, and permissions to be loaded. */
(void) fprintf(stderr, "nEnter shm_perm.uid: ");
(void) scanf("%hi", &shmid_ds.shm_perm.uid);
(void) fprintf(stderr, "Enter shm_perm.gid: ");
(void) scanf("%hi", &shmid_ds.shm_perm.gid);
(void) fprintf(stderr,"Note: Keep read permission for yourself.n");
(void) fprintf(stderr, "Enter shm_perm.mode: ");
(void) scanf("%hi", &shmid_ds.shm_perm.mode);
break;
case IPC_RMID:
/* Remove the segment when the last attach point is detached. */
break;
case SHM_LOCK:
/* Lock the shared memory segment. */
break;
case SHM_UNLOCK:
/* Unlock the shared memory segment. */
break;
default:
/* Unknown command will be passed to shmctl. */
break;
}
do_shmctl(shmid, cmd, &shmid_ds);
exit(0);
}
static void do_shmctl(shmid, cmd, buf)
int shmid;
int cmd;
struct shmid_ds *buf; /* pointer to shared memory data structure */
{
register int rtrn; /* hold area */
(void) fprintf(stderr, "shmctl Calling shmctl(%d, %d,buf)n",shmid, cmd);
if (cmd == IPC_SET) {
(void) fprintf(stderr, "tbuf->shm_perm.uid == %dn", buf->shm_perm.uid);
(void) fprintf(stderr, "tbuf->shm_perm.gid == %dn", buf->shm_perm.gid);
(void) fprintf(stderr, "tbuf->shm_perm.mode == %#on",buf->shm_perm.mode);
}
if ((rtrn = shmctl(shmid, cmd, buf)) == -1) {
perror("shmctl: shmctl failed");
exit(1);
}
else {
(void) fprintf(stderr, "shmctl: shmctl returned %dn", rtrn);
}
if (cmd != IPC_STAT && cmd != IPC_SET)
return;
/* Print the current status. */
(void) fprintf(stderr, "nCurrent status:n");
(void) fprintf(stderr, "tshm_perm.uid = %dn",buf->shm_perm.uid);
(void) fprintf(stderr, "tshm_perm.gid = %dn",buf->shm_perm.gid);
(void) fprintf(stderr, "tshm_perm.cuid = %dn",buf->shm_perm.cuid);
(void) fprintf(stderr, "tshm_perm.cgid = %dn", buf->shm_perm.cgid);
(void) fprintf(stderr, "tshm_perm.mode = %#on", buf->shm_perm.mode);
(void) fprintf(stderr, "tshm_perm.key = %#xn", buf->shm_perm.key);
(void) fprintf(stderr, "tshm_segsz = %dn", buf->shm_segsz);
(void) fprintf(stderr, "tshm_lpid = %dn", buf->shm_lpid);
(void) fprintf(stderr, "tshm_cpid = %dn", buf->shm_cpid);
(void) fprintf(stderr, "tshm_nattch = %dn", buf->shm_nattch);
(void) fprintf(stderr, "tshm_atime = %s",buf->shm_atime ? ctime(&buf->shm_atime) : "Not Setn");
(void) fprintf(stderr, "tshm_dtime = %s",buf->shm_dtime ? ctime(&buf->shm_dtime) : "Not Setn");
(void) fprintf(stderr, "tshm_ctime = %s",ctime(&buf->shm_ctime));
} |
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