rwarray(3am) - man - phpMan

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  multidimen‐
              sional 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  re‐
              turn 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 tra‐
       versal 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.   How‐
       ever, 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), ord‐
       chr(3am), readdir(3am), readfile(3am), revoutput(3am), time(3am).

AUTHOR
       Arnold Robbins, arnold AT skeeve.com.

COPYING PERMISSIONS
       Copyright © 2012, 2013, 2018, 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  distrib‐
       uted 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  no‐
       tice may be stated in a translation approved by the Foundation.



Free Software Foundation                     Feb 02 2018                                RWARRAY(3am)