From 3ebc83e38181515e3aef5a3dd1ce6daf3edaf9a6 Mon Sep 17 00:00:00 2001
From: Eric Andersen <andersen@codepoet.org>
Date: Mon, 21 May 2001 23:00:16 +0000
Subject: rewrite to accomodate devfs

---
 libc/termios/ttyname.c | 90 +++++++++++++++++++++++++++++++++-----------------
 1 file changed, 60 insertions(+), 30 deletions(-)

(limited to 'libc/termios/ttyname.c')

diff --git a/libc/termios/ttyname.c b/libc/termios/ttyname.c
index 2aa009104..f7f066e61 100644
--- a/libc/termios/ttyname.c
+++ b/libc/termios/ttyname.c
@@ -4,39 +4,69 @@
 #include <sys/stat.h>
 #include <dirent.h>
 
+static char * __check_dir_for_tty_match(char * dirname, struct stat *st)
+{
+    DIR *fp;
+    struct stat dst;
+    struct dirent *d;
+    static char name[NAME_MAX];
+
+    fp = opendir(dirname);
+    if (fp == 0)
+	return 0;
+    strcpy(name, dirname);
+    strcat(name, "/");
+
+    while ((d = readdir(fp)) != 0) {
+	strcpy(name + sizeof(dirname), d->d_name);
+	if (stat(name, &dst) == 0
+		&& st->st_dev == dst.st_dev && st->st_ino == dst.st_ino) {
+	    closedir(fp);
+	    return name;
+	}
+    }
+    closedir(fp);
+    return NULL;
+}
+
+/* This is a failly slow approach.  We do a linear search through
+ * some directories looking for a match.  Yes this is lame.  But 
+ * it should work, should be small, and will return names that match
+ * what is on disk.  
+ *
+ * Another approach we could use would be to use the info in /proc/self/fd */
 char *ttyname(fd)
 int fd;
 {
-	static char dev[] = "/dev";
-	struct stat st, dst;
-	DIR *fp;
-	struct dirent *d;
-	static char name[NAME_MAX];
-	int noerr = errno;
-
-	if (fstat(fd, &st) < 0)
-		return 0;
-	if (!isatty(fd)) {
-		__set_errno(ENOTTY);
-		return 0;
-	}
+    char *the_name = NULL;
+    struct stat st;
+    int noerr = errno;
 
-	fp = opendir(dev);
-	if (fp == 0)
-		return 0;
-	strcpy(name, dev);
-	strcat(name, "/");
-
-	while ((d = readdir(fp)) != 0) {
-		strcpy(name + sizeof(dev), d->d_name);
-		if (stat(name, &dst) == 0
-			&& st.st_dev == dst.st_dev && st.st_ino == dst.st_ino) {
-			closedir(fp);
-			__set_errno(noerr);
-			return name;
-		}
-	}
-	closedir(fp);
-	__set_errno(noerr);
+    if (fstat(fd, &st) < 0)
 	return 0;
+
+    if (!isatty(fd)) {
+	noerr = ENOTTY;
+	goto cool_found_it;
+    }
+
+    /* Lets try /dev/vc first (be devfs compatible) */
+    if ( (the_name=__check_dir_for_tty_match("/dev/vc", &st))) 
+	goto cool_found_it;
+
+    /* Lets try /dev/tts next (be devfs compatible) */
+    if ( (the_name=__check_dir_for_tty_match("/dev/tts", &st))) 
+	goto cool_found_it;
+
+    /* Lets try /dev/pts next */
+    if ( (the_name=__check_dir_for_tty_match("/dev/pts", &st))) 
+	goto cool_found_it;
+
+    /* Lets try walking through /dev last */
+    if ( (the_name=__check_dir_for_tty_match("/dev", &st))) 
+	goto cool_found_it;
+
+cool_found_it:
+    __set_errno(noerr);
+    return the_name;
 }
-- 
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