NAME    [Toc]    [Back]

     pathconf, fpathconf - get configurable pathname variables

SYNOPSIS    [Toc]    [Back]

     #include <unistd.h>

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

     long
     fpathconf(int fd, int name);

DESCRIPTION    [Toc]    [Back]

     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 a terminal  canonical
input line.

     _PC_MAX_INPUT
             The  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    [Toc]    [Back]

     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    [Toc]    [Back]

     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    [Toc]    [Back]

     sysconf(3), sysctl(3)

HISTORY    [Toc]    [Back]

     The pathconf  and  fpathconf  functions  first  appeared  in
4.4BSD.

OpenBSD      3.6                           June      4,      1993