Enrico Fraccaroli (Galfurian)
54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
#include <stdio.h>
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#include <string.h>
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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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int main(int argc, char *argv[])
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{
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key_t key;
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int shmid, id;
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char *str, *ptr;
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char *path;
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if (argc != 3) {
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printf("%s: You must provide a file and the id to generate the key.\n", argv[0]);
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return 1;
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}
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// Get the file.
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path = argv[1];
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// Get the id.
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id = strtol(argv[2], &ptr, 10);
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// Generate the key.
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key = ftok(path, id);
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if (key == -1) {
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perror("ftok");
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return EXIT_FAILURE;
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}
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printf("id = %d; key = %d\n", id, key);
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// Create shared memory.
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shmid = shmget(key, 1024, IPC_CREAT | 0666);
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if (shmid == -1) {
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perror("shmget");
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return EXIT_FAILURE;
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}
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printf("shmid = %d;\n", shmid);
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// Attach the shared memory.
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str = (char *)shmat(shmid, NULL, 0);
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if (str == NULL) {
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perror("shmat");
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return EXIT_FAILURE;
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}
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// Read the message.
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// printf("Write Data : ");
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// gets(str);
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strcpy(str, "Hello there!\n");
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// Print the message.
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printf("Data written in memory: %s\n", str);
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// Detatch the shared memory.
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if (shmdt(str) < 0) {
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perror("shmdt");
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return EXIT_FAILURE;
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}
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return EXIT_SUCCESS;
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}
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