FPATHCONF(3)        Linux Programmer's Manual        FPATHCONF(3)


NAME
       fpathconf, pathconf - get configuration values for files

SYNOPSIS
       #include <unistd.h>

       long fpathconf(int filedes, int name);
       long pathconf(char *path, int name);

DESCRIPTION
       fpathconf() gets a value for the configuration option name
       for the open file descriptor filedes.

       pathconf() gets a value for configuration option name  for
       the file name path.

       The  corresponding  macros  defined  in <unistd.h> minimum
       values; if an application wants to take advantage of  val-
       ues  which may change, a call to fpathconf() or pathconf()
       can be made, which may yield more liberal results.

       Setting name equal  to  one  of  the  following  constants
       returns the following configuration options:

       _PC_LINK_MAX
              returns  the  maximum  number of links to the file.
              If filedes or path refer to a directory,  then  the
              value  applies  to the whole directory.  The corre-
              sponding macro is _POSIX_LINK_MAX.

       _PC_MAX_CANON
              returns the maximum length  of  a  formatted  input
              line,  where filedes or path must refer to a termi-
              nal.  The corresponding macro is  _POSIX_MAX_CANON.

       _PC_MAX_INPUT
              returns  the maximum length of an input line, where
              filedes or path must refer to a terminal.  The cor-
              responding macro is _POSIX_MAX_INPUT.

       _PC_NAME_MAX
              returns  the  maximum  length  of a filename in the
              directory path or filedes.  the process is  allowed
              to create.  _POSIX_MAX_.

       _PC_PATH_MAX
              returns  the  maximum length of a relative pathname
              when path or filedes is the current working  direc-
              tory.   The corresponding macro is _POSIX_PATH_MAX.

       _PC_PIPE_BUF
              returns the size of the pipe buffer, where  filedes
              must refer to a pipe or FIFO and path must refer to
              a FIFO. The corresponding macro is _POSIX_PIPE_BUF.



GNU                       April 4, 1993                         1





FPATHCONF(3)        Linux Programmer's Manual        FPATHCONF(3)


       _PC_CHOWN_RESTRICTED
              returns  nonzero  if  the  chown(2) call may not be
              used on this file.  If filedes or path refer  to  a
              directory,  then  this applies to all files in that
              directory.     The    corresponding    macro     is
              _POSIX_CHOWN_RESTRICTED.

       _PC_NO_TRUNC
              returns  nonzero if accessing filenames longer than
              _POSIX_NAME_MAX generates  an  error.   The  corre-
              sponding macro is _POSIX_NO_TRUNC.

       _PC_VDISABLE
              returns nonzero if special character processing can
              be disabled, where filedes or path must refer to  a
              terminal.

RETURN VALUE
       The  limit is returned, if one exists.  If the system does
       not have  a  limit  for  the  requested  resource,  -1  is
       returned,  and  errno is unchanged.  If there is an error,
       -1 is returned, and errno is set to reflect the nature  of
       the error.

CONFORMS TO
       POSIX.1  Files  with  name  lengths  longer than the value
       returned for name equal to _PC_NAME_MAX may exist  in  the
       given directory.

       Some  returned  values  may be huge; they are not suitable
       for allocating memory.

SEE ALSO

getconf, statfs, open, sysconf,

GNU                       April 4, 1993                         2