fpathconf, pathconf — get configuration values for files
#include <unistd.h>
long
fpathconf( |
int | fd, |
int | name) ; |
long
pathconf( |
char * | path, |
int | name) ; |
fpathconf
() gets a value for
the configuration option name
for the open file
descriptor fd
.
pathconf
() gets a value for
configuration option name
for the filename
path
.
The corresponding macros defined in <
unistd.h
>
are minimum values; if an application wants to take advantage
of values which may change, a call to fpathconf
() or pathconf
() can be made, which may yield
more liberal results.
Setting name
equal
to one of the following constants returns the following
configuration options:
_PC_LINK_MAX
returns the maximum number of links to the file. If
fd
or
path
refer to a
directory, then the value applies to the whole
directory. The corresponding macro is _POSIX_LINK_MAX
.
_PC_MAX_CANON
returns the maximum length of a formatted input
line, where fd
or path
must
refer to a terminal. The corresponding macro is
_POSIX_MAX_CANON
.
_PC_MAX_INPUT
returns the maximum length of an input line, where
fd
or
path
must refer
to a terminal. The corresponding macro is _POSIX_MAX_INPUT
.
_PC_NAME_MAX
returns the maximum length of a filename in the
directory path
or fd
. the
process is allowed to create. The corresponding macro
is _POSIX_NAME_MAX
.
_PC_PATH_MAX
returns the maximum length of a relative pathname
when path
or
fd
is the
current working directory. The corresponding macro is
_POSIX_PATH_MAX
.
_PC_PIPE_BUF
returns the size of the pipe buffer, where
fd
must refer
to a pipe or FIFO and path
must refer to a
FIFO. The corresponding macro is _POSIX_PIPE_BUF
.
_PC_CHOWN_RESTRICTED
returns nonzero if the chown(2) call may not
be used on this file. If fd
or path
refer to a
directory, then this applies to all files in that
directory. The corresponding macro is _POSIX_CHOWN_RESTRICTED
.
_PC_NO_TRUNC
returns nonzero if accessing filenames longer than
_POSIX_NAME_MAX
generates
an error. The corresponding macro is _POSIX_NO_TRUNC
.
_PC_VDISABLE
returns nonzero if special character processing can
be disabled, where fd
or path
must refer to a
terminal.
The limit is returned, if one exists. If the system does
not have a limit for the requested resource, −1 is
returned, and errno
is
unchanged. If there is an error, −1 is returned, and
errno
is set to reflect the
nature of the error.
Files with name lengths longer than the value returned for
name
equal to
_PC_NAME_MAX
may exist in the
given directory.
Some returned values may be huge; they are not suitable for allocating memory.
This page is part of release 2.79 of the Linux man-pages
project. A
description of the project, and information about reporting
bugs, can be found at
http://www.kernel.org/doc/man-pages/.
(c) 1993 by Thomas Koenig (ig25rz.uni-karlsruhe.de) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. License. Modified Wed Jul 28 11:12:26 1993 by Rik Faith (faithcs.unc.edu) |