1#include <unistd.h> 2#include <errno.h> 3#include <sys/stat.h> 4 5void __procfdname(char *, unsigned); 6 7int ttyname_r(int fd, char *name, size_t size) 8{ 9 struct stat st1, st2; 10 char procname[sizeof "/proc/self/fd/" + 3*sizeof(int) + 2]; 11 ssize_t l; 12 13 if (!isatty(fd)) return ENOTTY; 14 15 __procfdname(procname, fd); 16 l = readlink(procname, name, size); 17 18 if (l < 0) return errno; 19 else if (l == size) return ERANGE; 20 21 name[l] = 0; 22 23 if (stat(name, &st1) || fstat(fd, &st2)) 24 return errno; 25 if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino) 26 return ENOENT; 27 28 return 0; 29} 30