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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  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.

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@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.



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