.TH RWARRAY 3am "Jan 15 2013" "Free Software Foundation" "GNU Awk Extension Modules"

.SH NAME

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

.SH SYNOPSIS

.ft CW

@load "rwarray"

.sp

ret = writea(file, array)

.br

ret = reada(file, array)

.ft R

.SH DESCRIPTION

The

.I rwarray

extension adds two functions named

.BR writea() .

and

.BR reada() ,

as follows.

.TP

.B 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.

.B writea()

understands multidimensional arrays.

It returns one on success, or zero upon failure.

.TP

.B reada()

is the inverse of

.BR 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.

.SH NOTES

The array created by

.B reada()

is identical to that written by

.B 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

.I gawk

to do so.

.PP

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.

.\" .SH BUGS

.SH EXAMPLE

.ft CW

.nf

@load "rwarray"

\&...

ret = writea("arraydump.bin", array)

\&...

ret = reada("arraydump.bin", array)

.fi

.ft R

.SH "SEE ALSO"

.IR "GAWK: Effective AWK Programming" ,

.IR filefuncs (3am),

.IR fnmatch (3am),

.IR fork (3am),

.IR inplace (3am),

.IR ordchr (3am),

.IR readdir (3am),

.IR readfile (3am),

.IR revoutput (3am),

.IR time (3am).

.SH AUTHOR

Arnold Robbins,

.BR arnold@skeeve.com .

.SH COPYING PERMISSIONS

Copyright \(co 2012, 2013,

Free Software Foundation, Inc.

.PP

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.

.ig

Permission is granted to process this file through troff and print the

results, provided the printed document carries copying permission

notice identical to this one except for the removal of this paragraph

(this paragraph not being relevant to the printed manual page).

..

.PP

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.

.PP

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.

.\" vim: set filetype=nroff :