PATHCONF(2) BSD System Calls Manual PATHCONF(2)

NAME
     ffppaatthhccoonnff, ppaatthhccoonnff - get configurable pathname variables

SYNOPSIS
     ##iinncclluuddee <>

     long
     ffppaatthhccoonnff(int fildes, int name);

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

DESCRIPTION
     The ppaatthhccoonnff() and ffppaatthhccoonnff() 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 ppaatthhccoonnff, the path argument is the name of a file or directory.  For
     ffppaatthhccoonnff, the fildes 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:

     PCLINKMAX
             The maximum file link count.

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

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

     PCNAMEMAX
             The maximum number of bytes in a file name.

     PCPATHMAX
             The maximum number of bytes in a pathname.

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

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

     PCNOTRUNC
             Return 1 if file names longer than KERNNAMEMAX are truncated.

     PCVDISABLE
             Returns the terminal character disabling value.

RETURN VALUES
     If the call to ppaatthhccoonnff or ffppaatthhccoonnff 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.

EERRRROORRSS
     If any of the following conditions occur, the ppaatthhccoonnff and ffppaatthhccoonnff
     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.

     PPaatthhccoonnff() will fail if:

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

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

     [ELOOP]         Too many symbolic links are encountered in translating
                     the pathname.  This is taken to be indicative of a loop-
                     ing symbolic link.

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

     [ENOENT]        The named file does not exist.

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

     FFppaatthhccoonnff() will fail if:

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

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

SEE ALSO
     sysctl(3)

HISTORY     The ppaatthhccoonnff and ffppaatthhccoonnff functions first appeared in 4.4BSD.

4th Berkeley Distribution        June 4, 1993        4th Berkeley Distribution