#!/usr/bin/perl -w 
use strict; 
use Tie::File; 
  
#open 
my $archivo = 'test-pdf.tex'; 
  
my @coment=split(/\\begin{document}/, $archivo,2); 
#Usamos tie 
tie @coment, 'Tie::File', $archivo or die "No coment lines: $!"; 
#search 
foreach my $line (@coment) { 
# Coment 
$line =~ s/(\\usepackage){pst/\%\\usepackage{pst/i; 
} 
#close 
untie @coment;

##</code><code>##

\RequirePackage{graphicx}
\let\IncludeGraphics\includegraphics
\graphicspath{{images/}}
\documentclass[10pt]{article}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{pstricks}
\usepackage{pstricks-add}
\usepackage[spanish]{babel}
\usepackage{microtype}% sólo pdftex
\begin{document}
Example code
\begin{verbatim}
\documentclass[10pt]{article}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{pstricks}
\usepackage{pstricks-add}
\usepackage[spanish]{babel}
\usepackage{microtype}% sólo pdflatex
\begin{document}
\begin{pspicture}[showgrid=true](4,2)
\psscaleboxto(8,2){Hola}
\end{pspicture}
\begin{pspicture}[showgrid=true](4,2)
\psscaleboxto(4,2){foo bar}
\end{pspicture}
\end{document}
\end{verbatim}
Obtain
 \IncludeGraphics[scale=1]{test-tmp-0.pdf}
and
\IncludeGraphics[scale=1]{test-tmp-1.pdf}
\end{document}

##</code><code>##

\RequirePackage{graphicx}
\let\IncludeGraphics\includegraphics
\graphicspath{{images/}}
\documentclass[10pt]{article}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
%\usepackage{pstricks} this is ok
%\usepackage{pstricks-add} this is ok 
\usepackage[spanish]{babel}
\usepackage{microtype}% sólo pdftex
\begin{document}
Example code
\begin{verbatim}
\documentclass[10pt]{article}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
%\usepackage{pstricks} %%%%this is wrong
%\usepackage{pstricks-add} %%%%this is wrong
\usepackage[spanish]{babel}
\usepackage{microtype}% sólo pdflatex
\begin{document}
\begin{pspicture}[showgrid=true](4,2)
\psscaleboxto(8,2){Hola}
\end{pspicture}
\begin{pspicture}[showgrid=true](4,2)
\psscaleboxto(4,2){foo bar}
\end{pspicture}
\end{document}
\end{verbatim}
Obtain
 \IncludeGraphics[scale=1]{test-tmp-0.pdf}
and
\IncludeGraphics[scale=1]{test-tmp-1.pdf}
\end{document}