fpathconf
NAME
fpathconf, pathconf - get configuration values for files
SYNOPSIS
#include <unistd.h> I long fpathconf(int filedes , int name );
I long pathconf(char * path , int name );
DESCRIPTION
R fpathconf ()
gets a value for the configuration option
name
for the open file descriptor
R filedes .
R pathconf ()
gets a value for configuration option
name
for the filename
R 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
R fpathconf ()
or
R 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
filedes
or
path
refer to a directory, then the value applies to the whole directory.
The corresponding macro is
R _POSIX_LINK_MAX .
_PC_MAX_CANON
returns the maximum length of a formatted input line, where
filedes
or
path
must refer to a terminal.
The corresponding macro is
R _POSIX_MAX_CANON .
_PC_MAX_INPUT
returns the maximum length of an input line, where
filedes
or
path
must refer to a terminal.
The corresponding macro is
R _POSIX_MAX_INPUT .
_PC_NAME_MAX
returns the maximum length of a filename in the directory
path
or
R filedes .
the process is allowed to create.
The corresponding macro is
R _POSIX_NAME_MAX .
_PC_PATH_MAX
returns the maximum length of a relative pathname when
path
or
filedes
is the current working directory.
The corresponding macro is
R _POSIX_PATH_MAX .
_PC_PIPE_BUF
returns the size of the pipe buffer, where
filedes
must refer to a pipe or FIFO and
path
must refer to a FIFO.
The corresponding macro is
R _POSIX_PIPE_BUF .
_PC_CHOWN_RESTRICTED
returns non-zero if the
chown(2)
call may not be used on this file.
If
filedes
or
path
refer to a directory, then this applies to all files in that
directory.
The corresponding macro is
R _POSIX_CHOWN_RESTRICTED .
_PC_NO_TRUNC
returns non-zero if accessing filenames longer than
_POSIX_NAME_MAX
generates an error.
The corresponding macro is
R _POSIX_NO_TRUNC .
_PC_VDISABLE
returns non-zero if special character processing can be disabled, where
filedes
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.
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