45 lines
1.2 KiB
C++
45 lines
1.2 KiB
C++
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#include <stdio.h>
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#include <stdlib.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <sys/mman.h>
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#include <string.h>
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#include <sys/stat.h>
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int main(int argc, char *argv[])
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{
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int s, d;
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struct stat st;
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void *sp, *dp;
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s = open(argv[1], O_RDONLY);
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if (s == -1) {
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perror("open source");
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exit(1);
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}
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d = open(argv[2], O_RDWR | O_CREAT | O_TRUNC, 0644);
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if (d == -1) {
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perror("open destintation");
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exit(1);
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}
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if (fstat(s, &st)) {
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perror("stat source");
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exit(1);
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}
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if (ftruncate(d, st.st_size)) {
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perror("truncate destination");
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exit(1);
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}
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sp = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, s, 0);
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if (sp == MAP_FAILED) {
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perror("map source");
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exit(1);
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}
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dp = mmap(NULL, st.st_size, PROT_WRITE | PROT_READ, MAP_SHARED, d, 0);
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if (dp == MAP_FAILED) {
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perror("map destintation");
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exit(1);
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}
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memcpy(dp, sp, st.st_size);
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return 0;
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}
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