threads/76938: include/unistd.h: ttyname_r prototype missing
Craig Rodrigues
rodrigc at crodrigues.org
Fri Mar 18 07:20:04 PST 2005
The following reply was made to PR threads/76938; it has been noted by GNATS.
From: Craig Rodrigues <rodrigc at crodrigues.org>
To: freebsd-gnats-submit at freebsd.org
Cc: tmclaugh at sdf.lonestar.org
Subject: Re: threads/76938: include/unistd.h: ttyname_r prototype missing
Date: Fri, 18 Mar 2005 10:19:30 -0500
Hi,
I updated the patch to take care of some buildworld
problems in libc_r and libthr (remove two extern declarations
of ttyname_r).
--- lib/libc/gen/ttyname.3.orig Wed Mar 9 17:13:58 2005
+++ lib/libc/gen/ttyname.3 Thu Mar 17 20:00:02 2005
@@ -37,6 +37,7 @@
.Os
.Sh NAME
.Nm ttyname ,
+.Nm ttyname_r ,
.Nm isatty ,
.Nm ttyslot
.Nd get name of associated terminal (tty) from file descriptor
@@ -46,7 +47,7 @@
.In unistd.h
.Ft char *
.Fn ttyname "int fd"
-.Ft char *
+.Ft int
.Fn ttyname_r "int fd" "char *buf" "size_t len"
.Ft int
.Fn isatty "int fd"
@@ -82,7 +83,13 @@
gets the related device name of
a file descriptor for which
.Fn isatty
-is true
+is true.
+.Pp
+.Fn ttyname
+returns the name stored in a static buffer which will be overwritten
+on subsequent calls.
+.Fn ttyname_r
+takes a buffer and length as arguments to avoid this problem.
.Pp
The
.Fn ttyslot
@@ -100,12 +107,25 @@
a
.Dv NULL
pointer is returned.
+The
+.Fn ttyname_r
+function returns 0 if successful. Otherwise an error number is returned.
.Pp
The
.Fn ttyslot
function
returns the unit number of the device file if found; otherwise
the value zero is returned.
+.Sh ERRORS
+.Fn ttyname_r
+may return the following error codes:
+.Bl -tag -width Er
+.It Bq Er ENOTTY
+.Fa fd
+is not a valid file descriptor.
+.It Bq Er ERANGE
+.Fa bufsize
+is smaller than the length of the string to be returned.
.Sh FILES
.Bl -tag -width /etc/ttys -compact
.It Pa /dev/\(**
@@ -123,11 +143,6 @@
function
appeared in
.At v7 .
-.Sh BUGS
-The
-.Fn ttyname
-function leaves its result in an internal static object and returns
-a pointer to that object.
-Subsequent calls to
-.Fn ttyname
-will modify the same object.
+.Fn ttyname_r
+appeared in
+.Fx 6.0 .
--- lib/libc/gen/ttyname.c.orig Thu Mar 17 10:39:08 2005
+++ lib/libc/gen/ttyname.c Thu Mar 17 11:15:42 2005
@@ -50,6 +50,7 @@
#include <string.h>
#include <paths.h>
#include <pthread.h>
+#include <errno.h>
#include "un-namespace.h"
#include "libc_private.h"
@@ -60,34 +61,32 @@
static pthread_key_t ttyname_key;
static int ttyname_init = 0;
-char *
+int
ttyname_r(int fd, char *buf, size_t len)
{
struct stat sb;
- char *rval;
struct fiodgname_arg fgn;
- rval = NULL;
*buf = '\0';
/* Must be a terminal. */
if (!isatty(fd))
- return (rval);
+ return (ENOTTY);
/* Must be a character device. */
if (_fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
- return (rval);
+ return (ENOTTY);
/* Must have enough room */
if (len <= sizeof(_PATH_DEV))
- return (rval);
+ return (ERANGE);
strcpy(buf, _PATH_DEV);
fgn.len = len - strlen(buf);
fgn.buf = buf + strlen(buf);
if (!_ioctl(fd, FIODGNAME, &fgn))
- return(buf);
+ return (EINVAL);
devname_r(sb.st_rdev, S_IFCHR,
buf + strlen(buf), sizeof(buf) - strlen(buf));
- return (buf);
+ return (0);
}
char *
@@ -95,8 +94,12 @@
{
char *buf;
- if (__isthreaded == 0)
- return (ttyname_r(fd, ttyname_buf, sizeof ttyname_buf));
+ if (__isthreaded == 0) {
+ if (ttyname_r(fd, ttyname_buf, sizeof ttyname_buf) != 0)
+ return (NULL);
+ else
+ return (ttyname_buf);
+ }
if (ttyname_init == 0) {
_pthread_mutex_lock(&ttyname_lock);
@@ -121,6 +124,7 @@
return (NULL);
}
}
- return (ttyname_r(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN));
+ ttyname_r(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN);
+ return (buf);
}
--- include/unistd.h.orig Thu Feb 17 17:37:41 2005
+++ include/unistd.h Thu Feb 17 17:38:19 2005
@@ -365,6 +365,7 @@
pid_t tcgetpgrp(int);
int tcsetpgrp(int, pid_t);
char *ttyname(int);
+int ttyname_r(int, char *, size_t);
int unlink(const char *);
ssize_t write(int, const void *, size_t);
--- lib/libc_r/uthread/pthread_private.h.orig Thu Mar 17 21:49:16 2005
+++ lib/libc_r/uthread/pthread_private.h Thu Mar 17 22:13:39 2005
@@ -1213,7 +1213,6 @@
__BEGIN_DECLS
char *__ttyname_basic(int);
char *__ttyname_r_basic(int, char *, size_t);
-char *ttyname_r(int, char *, size_t);
void _cond_wait_backout(pthread_t);
void _fd_lock_backout(pthread_t);
int _find_thread(pthread_t);
--- lib/libthr/thread/thr_private.h.orig Thu Mar 17 22:09:53 2005
+++ lib/libthr/thread/thr_private.h Thu Mar 17 22:11:06 2005
@@ -771,7 +771,6 @@
__BEGIN_DECLS
char *__ttyname_basic(int);
char *__ttyname_r_basic(int, char *, size_t);
-char *ttyname_r(int, char *, size_t);
void _cond_wait_backout(pthread_t);
int _find_thread(pthread_t);
pthread_t _get_curthread(void);
--
Craig Rodrigues
rodrigc at crodrigues.org
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