pathconf(2)                                                 pathconf(2)

  pathconf()

  NAME

    pathconf(), wcs_pathconf(), fpathconf() - get configurable pathname
    variables

  SYNOPSIS

    #include 

    long pathconf (const char *path, int name)
    long wcs_pathconf (const wchar_t *path, int name)
    long fpathconf (int fd, int name)

  DESCRIPTION

    The pathconf(2) and wcs_pathconf(2) functions are identical, except that
    wcs_pathconf(2) accepts wide characters in the path argument.

    The pathconf(2), wcs_pathconf(2), and fpathconf(2) functions provide 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(2) or wcs_pathconf(2), the path argument is the name of a
    file or directory. For fpathconf(2), 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
    .

    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.

  RETURN VALUES

    If the call to pathconf(2), wcs_pathconf(2), or fpathconf(2) 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(2),
    wcs_pathconf(2), and fpathconf(2) functions 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.
    The pathconf(2) or wcs_pathconf(2) call will fail if:

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

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

    [ELOOP]
        Too many symbolic links were encountered in translating the pathname.

    [ENAMETOOLONG]
        A component of a pathname exceeded {NAME_MAX} characters, or an entire
        pathname exceeded {PATH_MAX} characters.

    [ENOENT]
        The named file does not exist.

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

    The fpathconf(2) call 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.

  USAGE NOTES

    All of these functions are thread safe.

    All of these functions are async-signal safe.