31 lines
577 B
C
31 lines
577 B
C
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#include <unistd.h>
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#include <fcntl.h>
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#include <sys/mman.h>
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#include <string.h>
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#include <stdio.h>
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int main(int argc, char **argv)
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{
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int fd = open(argv[1], O_RDWR | O_CREAT, (mode_t)0600);
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const char *text = "hello";
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size_t textsize = strlen(text) + 1;
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char *map;
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lseek(fd, textsize-1, SEEK_SET);
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write(fd, "", 1);
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map = mmap(0, textsize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
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printf("address is 0x%x\n", (unsigned long)map);
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memcpy(map, text, strlen(text));
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//while(1);
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msync(map, textsize, MS_SYNC);
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munmap(map, textsize);
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close(fd);
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return 0;
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}
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