fpathconf, pathconf - get configuration values for files
SYNOPSIS
#include <unistd.h>long fpathconf(int fd, int name); long pathconf(char *path, int name);
DESCRIPTION
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
that 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 non-zero 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 non-zero if accessing filenames longer than
_POSIX_NAME_MAX
generates an error.
The corresponding macro is
_POSIX_NO_TRUNC.
_PC_VDISABLE
returns non-zero if special character processing can be disabled, where
fd
or
path
must refer to a terminal.
RETURN VALUE
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.
CONFORMING TO
POSIX.1-2001.
NOTES
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 3.14 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/.
