#<p>
#  Copy a file, replacing strings.
#</p>
#<p>
# <b>Author:</b> Steve Wampler (<i>sbw@tapestry.tucson.az.us</i>)
#</p>
#<p>
#  This file is in the <i>public domain</i>.
#</p>

import util

#<p>
#  Copy standard input to standard output, replacing substrings with
#  matching replacement.
#</p>
#<p>
#  Arguments are of the form <b>oldString=newString</b>, where
#  <b>oldString</b> will be replaced by <b>newString</b>.
#</p>
#<p>
#   Note that <b>oldString</b> cannot include "<b>=</b>", but that
#   <b>newString</b> can.
#</p>
procedure main(args)

     if (*args = 0) | ("--help" == !args) then 
         stop("Usage: mapStrings [oldString=newString]... <infile >outfile")

     sr := StringReplacer(buildMap(args))
     bRead := BlockRead(&input,4096)
     while writes(sr.replace(bRead.readBlock()))
     
end

#<p>
#  Construct the replacement map.
#  <i>Used internally.</i>
#</p>
procedure buildMap(args)
    local mapTable := table()
    every arg := !args do {
        arg ? mapTable[tab(upto('='))] := (move(1),tab(0))
        }
    return mapTable
end