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PATHCONF(2)                   System Calls Manual                  PATHCONF(2)

     pathconf, fpathconf - get configurable pathname variables

     Standard C Library (libc, -lc)

     #include <unistd.h>

     pathconf(const char *path, int name);

     fpathconf(int fd, int name);

     The pathconf() and fpathconf() 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, 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 <unistd.h> header.

     The available values are as follows:

             The maximum file link count.

             The maximum number of bytes in terminal canonical input line.

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

             The maximum number of bytes in a filename, not including a
             terminating null character.

             The maximum number of bytes in a pathname, including the
             terminating null character.

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

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

             Return 0 if filenames longer than {NAME_MAX} are silently
             truncated, or non-zero if an error is generated when {NAME_MAX}
             is exceeded.

             Returns the terminal character disabling value.

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

             If the maximum size file that could ever exist on the mounted
             file system is maxsize, then the returned value is 2 plus the
             floor of the base 2 logarithm of maxsize.

             The maximum number of bytes in a symbolic link.

             When referring to a directory the system supports the creation of
             symbolic links within that directory; for nondirectory files, the
             meaning of {_PC_2_SYMLINKS} is undefined.

     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.

     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, or the
                        implementation does not support an association of the
                        variable name with the associated file.

     pathconf() will fail if:

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

     [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 path name exceeded {PATH_MAX} characters.

     [ENOENT]        The named file does not exist.

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

     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


     The pathconf() and fpathconf() functions conform to IEEE Std 1003.1-1990

     The pathconf and fpathconf functions first appeared in 4.4BSD.

NetBSD 10.99                     July 26, 2010                    NetBSD 10.99