ladybird/Userland/cp.cpp
Andreas Kling 1b16a29044 Kernel+Userland: Implement fchmod() syscall and use it to improve /bin/cp.
/bin/cp will now copy the permission bits from source to destination. :^)
2019-03-01 10:39:19 +01:00

65 lines
1.4 KiB
C++

#include <unistd.h>
#include <fcntl.h>
#include <assert.h>
#include <stdio.h>
#include <sys/stat.h>
int main(int argc, char** argv)
{
if (argc != 3) {
printf("usage: cp <source> <destination>\n");
return 0;
}
int src_fd = open(argv[1], O_RDONLY);
if (src_fd < 0) {
perror("open src");
return 1;
}
int dst_fd = open(argv[2], O_WRONLY | O_CREAT);
if (dst_fd < 0) {
perror("open dst");
return 1;
}
struct stat src_stat;
int rc = fstat(src_fd, &src_stat);
if (rc < 0) {
perror("stat src");
return 1;
}
for (;;) {
char buffer[BUFSIZ];
ssize_t nread = read(src_fd, buffer, sizeof(buffer));
if (nread < 0) {
perror("read src");
return 1;
}
if (nread == 0)
break;
ssize_t remaining_to_write = nread;
char* bufptr = buffer;
while (remaining_to_write) {
ssize_t nwritten = write(dst_fd, bufptr, remaining_to_write);
if (nwritten < 0) {
perror("write dst");
return 1;
}
assert(nwritten > 0);
remaining_to_write -= nwritten;
bufptr += nwritten;
}
}
rc = fchmod(dst_fd, src_stat.st_mode);
if (rc < 0) {
perror("fchmod dst");
return 1;
}
close(src_fd);
close(dst_fd);
return 0;
}