source: azure_iot_hub/trunk/musl-1.1.18/src/unistd/ttyname_r.c@ 388

#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)) return ENOTTY;

        __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;
}