mirror of
https://github.com/autc04/Retro68.git
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43 lines
659 B
C
43 lines
659 B
C
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#include <sys/types.h>
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#include <sys/mman.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 <fcntl.h>
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#include "check.h"
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int main()
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{
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int fd;
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char *x;
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FILE *fp;
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char buf[40];
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fd = open("my.file", O_CREAT | O_TRUNC | O_RDWR, 0644);
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CHECK (fd != -1);
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CHECK (write (fd, "abcdefgh", 8) == 8);
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x = (char *)mmap (0, 20, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
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CHECK (x != MAP_FAILED);
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x[3] = 'j';
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CHECK (munmap (x, 20) == 0);
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CHECK (close(fd) != -1);
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fp = fopen("my.file","r");
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CHECK (fp != NULL);
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CHECK (fread(buf, 1, 20, fp) == 8);
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CHECK (strncmp (buf, "abcjefgh", 8) == 0);
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exit (0);
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}
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