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Ben Harris 2016-09-29 14:28:39 -04:00
commit 9215caf9c5
1 changed files with 44 additions and 0 deletions
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#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>
#include <string.h>
#include <sys/stat.h>
int main(int argc, char *argv[])
{
int s, d;
struct stat st;
void *sp, *dp;
s = open(argv[1], O_RDONLY);
if (s == -1) {
perror("open source");
exit(1);
}
d = open(argv[2], O_RDWR | O_CREAT | O_TRUNC, 0644);
if (d == -1) {
perror("open destintation");
exit(1);
}
if (fstat(s, &st)) {
perror("stat source");
exit(1);
}
if (ftruncate(d, st.st_size)) {
perror("truncate destination");
exit(1);
}
sp = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, s, 0);
if (sp == MAP_FAILED) {
perror("map source");
exit(1);
}
dp = mmap(NULL, st.st_size, PROT_WRITE | PROT_READ, MAP_SHARED, d, 0);
if (dp == MAP_FAILED) {
perror("map destintation");
exit(1);
}
memcpy(dp, sp, st.st_size);
return 0;
}