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Updated: Thursday, June 13, 2019
 
 

rwarray (3)

Name

rwarray - write and read gawk arrays to/from files

Synopsis

@load "rwarray"

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

Description

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



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  multidimensional  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.


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+------------------+
       |ATTRIBUTE TYPE | ATTRIBUTE VALUE  |
       +---------------+------------------+
       |Availability   | text/gawk        |
       +---------------+------------------+
       |Stability      | Volatile         |
       +---------------+------------------+
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 implemen-
       tation issues, the array traversal order of the  recreated  array  will
       likely  be different from that of the original array.  As array traver-
       sal 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 net-
       work  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(3),  fnmatch(3),  fork(3),
       inplace(3), ordchr(3), readdir(3), readfile(3), revoutput(3), time(3).

AUTHOR
       Arnold Robbins, arnold@skeeve.com.

COPYING PERMISSIONS
       Copyright (C) 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  man-
       ual page into another language, under the above conditions for modified
       versions, except that this permission notice may be stated in a  trans-
       lation approved by the Foundation.


       This     software     was    built    from    source    available    at
       https://github.com/oracle/solaris-userland.   The  original   community
       source                was                downloaded                from
       https://ftp.gnu.org/gnu/gawk/gawk-4.2.1.tar.xz

       Further information about this software can be found on the open source
       community website at https://www.gnu.org/software/gawk.



Free Software Foundation          Jan 15 2013                       RWARRAY(3)