53 lines
1.3 KiB
C
53 lines
1.3 KiB
C
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/* Mecanismes de communication entre processus - IPC */
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/* Creation d'une zone de m<>moire interne partaj<61>e (shared memory - shm ) */
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#include <stdlib.h>
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#include <sys/ipc.h>
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#include <sys/shm.h>
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#include <stdio.h>
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#define SHMEM_SIZE 256
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#define SHMEM_RIGHTS 0x01ff
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/* dimension de la zone : 255 octets */
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/* droits d'acc<63>s dans la zone de m<>more partag<61>e: 1ff */
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/* on nn'utilisera que le premier entier long pour l'exemple */
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int main (int argc, char ** argv) {
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/* l'identificateur externe (key) de la zone de m<>moire partag<61>e
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est un nombre entier transmis en param<EFBFBD>tre par l'utilisateur */
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int ipc_key ;
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int ipc_result ;
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char * pnl ;
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int i;
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if (argc<2)
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exit(1);
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ipc_key = atoi(argv[1]) ;
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/* creation de la zone commune : primitive shmget (....) */
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ipc_result = shmget(ipc_key, SHMEM_SIZE, IPC_CREAT|IPC_EXCL|SHMEM_RIGHTS) ;
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if (ipc_result != -1) {
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printf(" - Succes !! -\n");
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/* attachement <20> la zone de m<>moire partag<61>e : shmat (....) */
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pnl = (char*)shmat(ipc_result, 0, SHMEM_RIGHTS) ;
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/* initialisation avec 0 de la zone de m<>moire partag<61>e */
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for (i=0;i<SHMEM_SIZE;i++)
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pnl[i]='\0' ;
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}
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else
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printf(" Erreur :%d \n",ipc_result);
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exit(0) ;
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}
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