Skip site navigation (1)Skip section navigation (2)

FreeBSD Man Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
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
     applications 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,
             otherwise 0.

     _PC_SYNC_IO
             Returns 1 if synchronised I/O is supported for this file,
             otherwise 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
             specified 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
     variable 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
                        translating 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 11.0-PRERELEASE        November 4, 2002        FreeBSD 11.0-PRERELEASE

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

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=fpathconf&sektion=2&manpath=FreeBSD+5.0-RELEASE>

home | help