27 lines
421 B
C
27 lines
421 B
C
|
#include <lib.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
|
||
|
|
ssize_t pwrite(int fd, const void *buffer, size_t nbytes, off_t where)
|
||
|
|
{
|
||
|
|
off_t here;
|
||
|
|
ssize_t w;
|
||
|
|
|
||
|
|
if((here = lseek(fd, 0, SEEK_CUR)) < 0)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
if(lseek(fd, where, SEEK_SET) < 0)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
if((w=write(fd, buffer, nbytes)) < 0) {
|
||
|
|
int e = errno;
|
||
|
|
lseek(fd, here, SEEK_SET);
|
||
|
|
errno = e;
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
if(lseek(fd, here, SEEK_SET) < 0)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
return w;
|
||
|
|
}
|