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| | #include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
void __procfdname(char *, unsigned);
int ttyname_r(int fd, char *name, size_t size)
{
struct stat st1, st2;
char procname[sizeof "/proc/self/fd/" + 3*sizeof(int) + 2];
ssize_t l;
if (!isatty(fd)) {
if (errno != EBADF) errno = ENOTTY;
return errno;
}
__procfdname(procname, fd);
l = readlink(procname, name, size);
if (l < 0) return errno;
else if (l == size) return ERANGE;
name[l] = 0;
if (stat(name, &st1) || fstat(fd, &st2))
return errno;
if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
return ENODEV;
return 0;
}
|