46 lines
905 B
C
46 lines
905 B
C
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#include <fcntl.h>
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#include <unistd.h>
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#include <assert.h>
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#include <stdio.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <string.h>
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#define BLOCK_SIZE 1
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int main(int argc, char *argv[])
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{
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int fin,
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fout;
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char buf[BLOCK_SIZE];
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struct stat st;
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assert( argc == 3 );
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fin = open(argv[1],O_RDONLY);
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assert( fin >= 0 );
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fstat(fin, &st);
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char *src = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fin, 0);
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assert(src != MAP_FAILED);
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fout = open(argv[2],O_CREAT|O_RDWR|O_TRUNC,0600);
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assert( fout >= 0 );
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ftruncate(fout, st.st_size);
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char *dst = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fout, 0);
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assert(dst != MAP_FAILED);
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memcpy(dst, src, st.st_size);
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munmap(src, st.st_size);
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munmap(dst, st.st_size);
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close(fin);
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close(fout);
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return 0;
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}
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