RWARRAY(3) GNU Awk Extension Modules RWARRAY(3)
NAME
writea, reada, writeall, readall - write and read gawk arrays to/from
files
SYNOPSIS
@load "rwarray"
ret = writea(file, array)
ret = reada(file, array)
ret = writeall(file)
ret = readall(file)
DESCRIPTION
The rwarray extension adds functions named writea(), reada(), writeall(),
and readall(), 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.
writeall()
This function takes a string argument, which is the name of the
file to which dump the state of all variables. Calling this
function is completely equivalent to calling writea() with the
second argument equal to SYMTAB. It returns one on success, or
zero upon failure.
readall()
This function takes a string argument, which is the name of the
file from which to read the contents of various global variables.
For each variable in the file, the data is loaded unless the
variable already exists. If the variable already exists, the data
for that variable in the file is ignored. It returns one on
success, or 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)
...
ret = writeall("globalstate.bin")
...
ret = readall("globalstate.bin")
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, 2018, 2022 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 Mar 11 2022 RWARRAY(3)
gawk 5.2.0 - Generated Sun Sep 4 16:20:01 CDT 2022