Mega Code Archive
Copy file using mmap()
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#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>
#define PACKAGE "mmap"
int main(int argc, char *argv[]) {
int input, output;
size_t filesize;
void *source, *target;
if(argc != 3)
fprintf(stderr, "%s SOURCE DEST\n"), exit(1);
if((input = open(argv[1], O_RDONLY)) == -1)
fprintf(stderr, "%s: Error: opening file: %s\n", PACKAGE, argv[1]), exit(1);
if((output = open(argv[2], O_RDWR|O_CREAT|O_TRUNC, 0666)) == -1)
fprintf(stderr, "%s: Error: opening file: %s\n", PACKAGE, argv[2]), exit(1);
filesize = lseek(input, 0, SEEK_END);
lseek(output, filesize - 1, SEEK_SET);
write(output, '\0', 1);
if((source = mmap(0, filesize, PROT_READ, MAP_SHARED, input, 0)) == (void *) -1)
fprintf(stderr, "Error mapping input file: %s\n", argv[1]), exit(1);
if((target = mmap(0, filesize, PROT_WRITE, MAP_SHARED, output, 0)) == (void *) -1)
fprintf(stderr, "Error mapping ouput file: %s\n", argv[2]), exit(1);
memcpy(target, source, filesize);
munmap(source, filesize);
munmap(target, filesize);
close(input);
close(output);
return 0;
}
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