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PATHCONF(2)		  FreeBSD System Calls Manual		   PATHCONF(2)

NAME
     pathconf, fpathconf -- get	configurable pathname variables

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <unistd.h>

     long
     pathconf(const char *path,	int name);

     long
     fpathconf(int fd, int name);

DESCRIPTION
     The pathconf() and	fpathconf() functions provides a method	for applica-
     tions to determine	the current value of a configurable system limit or
     option variable associated	with a pathname	or file	descriptor.

     For pathconf(), the path argument is the name of a	file or	directory.
     For fpathconf(), the fd argument is an open file descriptor.  The name
     argument specifies	the system variable to be queried.  Symbolic constants
     for each name value are found in the include file <unistd.h>.

     The available values are as follows:

     _PC_LINK_MAX
	     The maximum file link count.

     _PC_MAX_CANON
	     The maximum number	of bytes in terminal canonical input line.

     _PC_MAX_INPUT
	     The minimum maximum number	of bytes for which space is available
	     in	a terminal input queue.

     _PC_NAME_MAX
	     The maximum number	of bytes in a file name.

     _PC_PATH_MAX
	     The maximum number	of bytes in a pathname.

     _PC_PIPE_BUF
	     The maximum number	of bytes which will be written atomically to a
	     pipe.

     _PC_CHOWN_RESTRICTED
	     Return 1 if appropriate privileges	are required for the chown(2)
	     system call, otherwise 0.

     _PC_NO_TRUNC
	     Return 1 if file names longer than	KERN_NAME_MAX are truncated.

     _PC_VDISABLE
	     Returns the terminal character disabling value.

     _PC_ASYNC_IO
	     Return 1 if asynchronous I/O is supported,	otherwise 0.

     _PC_PRIO_IO
	     Returns 1 if prioritised I/O is supported for this	file, other-
	     wise 0.

     _PC_SYNC_IO
	     Returns 1 if synchronised I/O is supported	for this file, other-
	     wise 0.

     _PC_ALLOC_SIZE_MIN
	     Minimum number of bytes of	storage	allocated for any portion of a
	     file.  path.

     _PC_FILESIZEBITS
	     Number of bits needed to represented the maximum file size.

     _PC_REC_INCR_XFER_SIZE
	     Recommended increment for file transfer sizes between
	     _PC_REC_MIN_XFER_SIZE and _PC_REC_MAX_XFER_SIZE.

     _PC_REC_MAX_XFER_SIZE
	     Maximum recommended file transfer size.

     _PC_REC_MIN_XFER_SIZE
	     Minimum recommended file transfer size.

     _PC_REC_XFER_ALIGN
	     Recommended file transfer buffer alignment.

     _PC_SYMLINK_MAX
	     Maximum number of bytes in	a symbolic link.

     _PC_ACL_EXTENDED
	     Returns 1 if an Access Control List (ACL) can be set on the spec-
	     ified file, otherwise 0.

     _PC_ACL_PATH_MAX
	     Maximum number of ACL entries per file.

     _PC_CAP_PRESENT
	     Returns 1 if a capability state can be set	on the specified file,
	     otherwise 0.

     _PC_INF_PRESENT
	     Returns 1 if an information label can be set on the specified
	     file, otherwise 0.

     _PC_MAC_PRESENT
	     Returns 1 if a Mandatory Access Control (MAC) label can be	set on
	     the specified file, otherwise 0.

RETURN VALUES
     If	the call to pathconf() or fpathconf() is not successful, -1 is
     returned and errno	is set appropriately.  Otherwise, if the variable is
     associated	with functionality that	does not have a	limit in the system,
     -1	is returned and	errno is not modified.	Otherwise, the current vari-
     able value	is returned.

ERRORS
     If	any of the following conditions	occur, the pathconf() and fpathconf()
     functions shall return -1 and set errno to	the corresponding value.

     [EINVAL]		The value of the name argument is invalid.

     [EINVAL]		The implementation does	not support an association of
			the variable name with the associated file.

     Pathconf()	will fail if:

     [ENOTDIR]		A component of the path	prefix is not a	directory.

     [ENAMETOOLONG]	A component of a pathname exceeded 255 characters, or
			an entire path name exceeded 1023 characters.

     [ENOENT]		The named file does not	exist.

     [EACCES]		Search permission is denied for	a component of the
			path prefix.

     [ELOOP]		Too many symbolic links	were encountered in translat-
			ing the	pathname.

     [EIO]		An I/O error occurred while reading from or writing to
			the file system.

     Fpathconf() will fail if:

     [EBADF]		fd is not a valid open file descriptor.

     [EIO]		An I/O error occurred while reading from or writing to
			the file system.

SEE ALSO
     sysctl(3)

HISTORY
     The pathconf() and	fpathconf() functions first appeared in	4.4BSD.

FreeBSD	10.1		       November	4, 2002			  FreeBSD 10.1

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | HISTORY

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