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

     pathconf, fpathconf -- get	configurable pathname variables

     #include <unistd.h>

     pathconf(const char *path,	int name);

     fpathconf(int fd, int name);

     The pathconf() and	fpathconf() functions provide 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:

	     The maximum file link count.

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

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

	     The maximum number	of bytes in a file name.

	     The maximum number	of bytes in a pathname.

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

	     Returns 1 if appropriate privileges are required for the chown(2)
	     system call, otherwise 0.	IEEE Std 1003.1-2001 ("POSIX.1") re-
	     quires appropriate	privilege in all cases,	but this behavior was
	     optional in prior editions	of the standard.

	     Returns 1 if attempts to use pathname components longer than
	     {NAME_MAX}	will result in an [ENAMETOOLONG] error;	otherwise,
	     such components will be truncated to {NAME_MAX}.  IEEE Std
	     1003.1-2001 ("POSIX.1") requires the error	in all cases, but this
	     behavior was optional in prior editions of	the standard, and some
	     non-POSIX-compliant file systems do not support this behavior.

	     Returns the terminal character disabling value.

	     Returns 1 if the filesystem supports the creation of symbolic
	     links within the specified	directory; the meaning of
	     _PC_2_SYMLINKS is unspecified for non-directory files.

	     Minimum number of bytes of	storage	allocated for any portion of a

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

	     Number of bits needed to represent	the maximum file size.

	     Returns 1 if prioritized I/O is supported,	otherwise 0.

	     Recommended increment for file transfer sizes between

	     Maximum recommended file transfer size.

	     Minimum recommended file transfer size.

	     Recommended file transfer buffer alignment.

	     Maximum number of bytes in	a symbolic link.

	     Returns 1 if synchronized I/O is supported, otherwise 0.

	     The resolution in nanoseconds of file timestamps.

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

     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.

     [EIO]		An I/O error occurred while reading from the file sys-

     pathconf()	will fail if:

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

     [ENAMETOOLONG]	A component of a pathname exceeded NAME_MAX characters
			(but see _PC_NO_TRUNC above), or an entire pathname
			(including the terminating NUL)	exceeded PATH_MAX

     [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.

     [EFAULT]		path points outside the	process's allocated address

     fpathconf() will fail if:

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

     sysctl(2),	sysconf(3)

     The pathconf() and	fpathconf() functions conform to IEEE Std 1003.1-2008

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

FreeBSD	13.0			 June 21, 2018			  FreeBSD 13.0


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