Globally replace text in several files

The task is to replace every occuring instance of a piece of text in a group of text files with another one. For this task we want to replace the text "Goodbye London!" with "Hello New York!" for a list of files.

Globally replace text in several files
You are encouraged to solve this task according to the task description, using any language you may know.

J

If files is a variable with the desired list of file names:

<lang j>require'strings' (1!:2~rplc&('Goodbye London!';'Hello New York!')@(1!:1))"0 files</lang>

Perl

<lang bash>perl -pi -e "s/Goodbye London\!/Hello New York\!/g;" a.txt b.txt c.txt</lang>

PicoLisp

<lang PicoLisp>(for File '(a.txt b.txt c.txt)

  (call 'mv File (tmp File))
  (out File
     (in (tmp File)
        (while (echo "Goodbye London!")
           (prin "Hello New York!") ) ) ) )</lang>

PureBasic

<lang PureBasic>Procedure GRTISF(List File$(), Find$, Replace$)

 Protected Line$, Out$, OutFile$, i
 ForEach File$()
   fsize=FileSize(File$())
   If fsize<=0: Continue: EndIf
   If ReadFile(0, File$())
     i=0
     ;
     ; generate a temporary file in a safe way
     Repeat
       file$=GetTemporaryDirectory()+base$+"_"+Str(i)+".tmp"
       i+1
     Until FileSize(file$)=-1
     i=CreateFile(FileID, file$)
     If i
       ; Copy the infile to the outfile while replacing any needed text
       While Not Eof(0)
         Line$=ReadString(0)
         Out$=ReplaceString(Line$,Find$,Replace$)
         WriteString(1,Out$)
       Wend
       CloseFile(1)
     EndIf
     CloseFile(0)
     If i
       ; If we made a new file, copy it back.
       CopyFile(file$, File$())
       DeleteFile(file$)
     EndIf
   EndIf
 Next

EndProcedure</lang> Implementation

NewList Xyz$()
AddElement(Xyz$()): Xyz$()="C:\\a.txt"
AddElement(Xyz$()): Xyz$()="C:\\b.txt"
AddElement(Xyz$()): Xyz$()="D:\\c.txt"

GRTISF(Xyz$(), "Goodbye London", "Hello New York")

Tcl

Library: Tcllib (Package: fileutil)

<lang tcl>package require Tcl 8.5 package require fileutil

1. Parameters to the replacement

set from "Goodbye London!" set to "Hello New York!"

1. Which files to replace

set fileList [list a.txt b.txt c.txt]

1. Make a command fragment that performs the replacement on a supplied string

set replacementCmd [list string map [list $from $to]]

1. Apply the replacement to the contents of each file

foreach filename $fileList {

   fileutil::updateInPlace $filename $replacementCmd

}</lang>