66 lines
1.8 KiB
C
66 lines
1.8 KiB
C
#include "common.h"
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#include <fcntl.h>
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#include <semaphore.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#define FAIL_TO_CLEANUP(cond, jmp_to) \
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if (cond) { \
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perror(#cond); \
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ret = EXIT_FAILURE; \
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goto jmp_to; \
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}
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int main(void) {
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int ret = 0;
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int shm_fd = -1;
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void *shm_ptr = MAP_FAILED;
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sem_t *sem_c2s = SEM_FAILED;
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sem_t *sem_s2c = SEM_FAILED;
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FAIL_TO_CLEANUP((shm_fd = shm_open(SHM_NAME, O_RDWR, 0)) == -1, exit);
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FAIL_TO_CLEANUP(
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(shm_ptr = mmap(NULL, SHM_SIZE,
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PROT_READ | PROT_WRITE,
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MAP_SHARED, shm_fd, 0)) == MAP_FAILED,
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unmap_shared_mem);
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FAIL_TO_CLEANUP((sem_c2s = sem_open(SEM_C2S_NAME, 0)) == SEM_FAILED,
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close_sem_c2s);
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FAIL_TO_CLEANUP((sem_s2c = sem_open(SEM_S2C_NAME, 0)) == SEM_FAILED,
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close_sem_s2c);
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char filename[SHM_SIZE];
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FAIL_TO_CLEANUP(fgets(filename, sizeof(filename), stdin) == NULL, close_sem_s2c);
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size_t ln = strlen(filename);
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if (ln > 0 && filename[ln - 1] == '\n')
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filename[ln - 1] = '\0';
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memset(shm_ptr, 0, SHM_SIZE);
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strncpy((char *)shm_ptr, filename, SHM_SIZE - 1);
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FAIL_TO_CLEANUP(sem_post(sem_c2s) == -1, close_sem_s2c);
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FAIL_TO_CLEANUP(sem_wait(sem_s2c) == -1, close_sem_s2c);
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size_t len = strnlen((char *)shm_ptr, SHM_SIZE);
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FAIL_TO_CLEANUP(fwrite(shm_ptr, sizeof(char), len, stdout) != len, close_sem_s2c);
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fflush(stdout); // don't really care if fails
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close_sem_s2c:
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sem_close(sem_s2c);
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close_sem_c2s:
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sem_close(sem_c2s);
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unmap_shared_mem:
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munmap(shm_ptr, SHM_SIZE);
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close_shared_fd:
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close(shm_fd);
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exit:
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return ret;
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}
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