#include <unistd.h> #include <errno.h> #include <stdio.h> #include <string.h> int ttyname_r(int fd, char *name, size_t size) { char procname[sizeof "/proc/self/fd/" + 3*sizeof(int) + 2]; ssize_t l; if (!isatty(fd)) return ENOTTY; snprintf(procname, sizeof procname, "/proc/self/fd/%d", fd); l = readlink(procname, name, size); if (l < 0) return errno; else if (l == size) return ERANGE; else return 0; }