From: Gavin Smith <gavinsmith0123@gmail.com>
To: libc-alpha@sourceware.org
Subject: [PATCH 1/1] document posix_openpt
Date: Wed, 12 Apr 2023 13:45:07 +0100 [thread overview]
Message-ID: <ZDan06Yc9Xex3rfq@starmint> (raw)
I copied the safety information from getpt, as I couldn't get this
information in full from anywhere else.
Your patch submission guide is contradictory as to whether to
use Signed-off-by or not
(https://sourceware.org/glibc/wiki/Contribution%20checklist):
> ... you just add a line saying:
> Signed-off-by: ...
> The project does not support or use "Signed-off-by" lines
commit be1468aa984d91e55db7719034ca9b8e53a7a136
Author: Gavin Smith <gavinsmith0123@gmail.com>
Date: Wed Apr 12 13:36:47 2023 +0100
manual: document posix_openpt (bug 17010)
* manual/terminal.texi (Allocation):
Document posix_openpt. State that getpt is similar to posix_openpt.
Use posix_openpt instead of getpt in example.
Signed-off-by: Gavin Smith <gavinsmith0123@gmail.com>
diff --git a/manual/terminal.texi b/manual/terminal.texi
index 7293bfb393..bdaee56053 100644
--- a/manual/terminal.texi
+++ b/manual/terminal.texi
@@ -1947,6 +1947,33 @@ This subsection describes functions for allocating a pseudo-terminal,
and for making this pseudo-terminal available for actual use. These
functions are declared in the header file @file{stdlib.h}.
+@deftypefun int posix_openpt (int @var{flags})
+@standards{POSIX.1, stdlib.h}
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{@acsfd{}}}
+
+@code{posix_openpt} returns a new file descriptor for the next
+available master pseudo-terminal. In the case of an error, it returns
+a value of @math{-1} instead, and sets @code{errno} to indicate
+the error. @xref{Opening and Closing Files} for possible values
+of @code{errno}.
+
+@var{flags} is a bit mask created from a bitwise OR of zero or more
+of the following flags:
+
+@table @code
+@item O_RDWR
+Open the device for both reading and writing. It is usual to specify
+this flag.
+@item O_NOCTTY
+Do not make the device the controlling terminal for the process.
+@end table
+
+These flags are defined in @file{fcntl.h}. @xref{Access Modes}.
+
+For this function to be available, @code{_XOPEN_SOURCE} must be defined
+to a value greater than @samp{600}. @xref{Feature Test Macros}.
+@end deftypefun
+
@deftypefun int getpt (void)
@standards{GNU, stdlib.h}
@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{@acsfd{}}}
@@ -1957,6 +1984,10 @@ functions are declared in the header file @file{stdlib.h}.
@c a devfs, and returns the fd; static variables devpts_mounted and
@c have_no_dev_ptmx are safely initialized so as to avoid repeated
@c tests.
+
+@code{getpt} is similar to @code{posix_openpt}. This function is a
+GNU extension and should not be used in portable programs.
+
The @code{getpt} function returns a new file descriptor for the next
available master pseudo-terminal. The normal return value from
@code{getpt} is a non-negative integer file descriptor. In the case of
@@ -1967,8 +1998,6 @@ an error, a value of @math{-1} is returned instead. The following
@item ENOENT
There are no free master pseudo-terminals available.
@end table
-
-This function is a GNU extension.
@end deftypefun
@deftypefun int grantpt (int @var{filedes})
@@ -2118,6 +2147,7 @@ This function is a GNU extension.
@end deftypefun
Typical usage of these functions is illustrated by the following example:
+
@smallexample
int
open_pty_pair (int *amaster, int *aslave)
@@ -2125,7 +2155,7 @@ open_pty_pair (int *amaster, int *aslave)
int master, slave;
char *name;
- master = getpt ();
+ master = posix_openpt (O_RDWR | O_NOCTTY);
if (master < 0)
return 0;
next reply other threads:[~2023-04-12 12:45 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-12 12:45 Gavin Smith [this message]
2023-04-19 12:43 ` Adhemerval Zanella Netto
2023-04-23 9:35 ` Gavin Smith
2023-04-26 12:20 ` Adhemerval Zanella Netto
2023-04-26 19:19 ` Gavin Smith
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