From e91c7b53c4775b789aca801f41ff02c0149c84dc Mon Sep 17 00:00:00 2001 From: Gavin Smith Date: Wed, 12 Apr 2023 13:45:07 +0100 Subject: manual: document posix_openpt (bug 17010) State that getpt is similar to posix_openpt. Use posix_openpt instead of getpt in example. Signed-off-by: Gavin Smith Reviewed-by: Adhemerval Zanella --- manual/terminal.texi | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) (limited to 'manual/terminal.texi') 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; -- cgit 1.4.1