/*
 * ttyname -- figure out the name of the terminal attached to a file
 * descriptor
 *
 * Written by Eric R. Smith and placed in the public domain.
 */

#include <sys/types.h>
#include <stat.h>
#include <dirent.h>
#include <string.h>

extern int __mint;

/* magic number alert! */
static char tname[32];

/* Find the file in directory "dir" that matches "sbuf". Returns 1
 * on success, 0 on failure. Note that "dir" is a prefix, i.e. it
 * should end with "/".
 */

static int
find_ino(dir, sb, name)
	char *dir;
	struct stat *sb;
	char *name;
{
	char *where = name;
	DIR *drv;
	struct dirent *next;
	struct stat testsb;

	drv = opendir(dir);
	if (!drv) return 0;

	while (*dir) {
		*where++ = *dir++;
	}

	while (next = readdir(drv)) {
		strcpy(where, next->d_name);
		if (stat(name, &testsb))
			continue;
		if (testsb.st_dev == sb->st_dev &&
		    testsb.st_ino == sb->st_ino) {
			closedir(drv);
			return 1;
		}
	}
	closedir(drv);
	return 0;
}

char *
ttyname(fd)
	int fd;
{
	char *name;
	struct stat sb;
	extern int isatty();

	if (!isatty(fd)) return (char *)0;

	if (__mint < 9) {
		if (fd == -2) {
			name = "/dev/aux";
		} else {
			name = "/dev/con";
		}
		strcpy(tname, name);
		return tname;
	}

	if (fstat(fd, &sb))
		return (char *)0;

	/* try the devices first */
	if (find_ino("/dev/", &sb, tname))
		return tname;

	/* hmmm, maybe we're a pseudo-tty */
	if (find_ino("u:/pipe/", tname))
		return tname;

	/* I give up */
	strcpy(tname, "/dev/tty");
	return tname;
}