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(3am), fnmatch(3am), fork(3am), inplace(3am),
       ordchr(3am), readdir(3am), readfile(3am), revoutput(3am), time(3am).

AUTHOR

       Arnold Robbins, arnold@skeeve.com.

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