RWARRAY(3am)                        GNU Awk Extension Modules                        RWARRAY(3am)



NAME
       writea, reada - write and read gawk arrays to/from files

SYNOPSIS
       @load "rwarray"

       ret = writea(file, array)
       ret = reada(file, array)

DESCRIPTION
       The rwarray extension adds two functions named writea().  and reada(), as follows.

       writea()
              This  function takes a string argument, which is the name of the file to which dump
              the array, and the array itself as the second argument.  writea() understands  mul‐
              tidimensional arrays.  It returns one on success, or zero upon failure.

       reada()
              is  the inverse of writea(); it reads the file named as its first argument, filling
              in the array named as the second argument. It clears the array  first.   Here  too,
              the return value is one on success and zero upon failure.

NOTES
       The  array  created  by reada() is identical to that written by writea() in the sense that
       the contents are the same. However, due to  implementation  issues,  the  array  traversal
       order of the recreated array will likely be different from that of the original array.  As
       array traversal order in AWK is by default undefined, this is not (technically) a problem.
       If  you  need to guarantee a particular traversal order, use the array sorting features in
       gawk to do so.

       The file contains binary data.  All integral values are written  in  network  byte  order.
       However,  double precision floating-point values are written as native binary data.  Thus,
       arrays containing only string data can theoretically be dumped on systems  with  one  byte
       order and restored on systems with a different one, but this has not been tried.

EXAMPLE
       @load "rwarray"
       ...
       ret = writea("arraydump.bin", array)
       ...
       ret = reada("arraydump.bin", array)

SEE ALSO
       GAWK:  Effective  AWK  Programming, filefuncs(3am), fnmatch(3am), fork(3am), inplace(3am),
       ordchr(3am), readdir(3am), readfile(3am), revoutput(3am), time(3am).

AUTHOR
       Arnold Robbins, arnold AT skeeve.com.

COPYING PERMISSIONS
       Copyright © 2012, 2013, Free Software Foundation, Inc.

       Permission is granted to make and distribute verbatim copies of this manual page  provided
       the copyright notice and this permission notice are preserved on all copies.

       Permission  is  granted to copy and distribute modified versions of this manual page under
       the conditions for verbatim copying, provided that the entire resulting  derived  work  is
       distributed under the terms of a permission notice identical to this one.

       Permission is granted to copy and distribute translations of this manual page into another
       language, under the above conditions for modified versions, except  that  this  permission
       notice may be stated in a translation approved by the Foundation.



Free Software Foundation                   Jan 15 2013                               RWARRAY(3am)