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From: aas@boeygen.nr.no (Gisle Aas)
Newsgroups: comp.lang.postscript
Subject: Re: PostScript page reverser?
Message-ID: <AAS.90Oct31201558@boeygen.nr.no>
Date: 31 Oct 90 19:15:58 GMT
References: <BOB.90Oct30100901@volitans.MorningStar.Com>
	<AAS.90Oct31191354@boeygen.nr.no>
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Reply-To: Gisle.Aas@nr.no
Organization: Norwegain Computing Centre, Oslo, Norway
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In-Reply-To: aas@boeygen.nr.no's message of 31 Oct 90 19:13:54

In article <AAS.90Oct31191354@boeygen.nr.no> aas@boeygen.nr.no (Gisle Aas) writes:

>   I once wrote the following perl program. (Not quite a one-line :-)

Since then I have learned not to write C for loops in perl. So here
you have a rewrite of my psrev program, done the perl way.

#!/usr/local/bin/perl
# Simple psrev clone in perl. Reverses pages of conforming postscript files.
# Author: Gisle Aas, NCC, Oslo.      email: <Gisle.Aas@nr.no>

@psfile = <>;                              # Slurp in the whole file
die "This is not a conforming PostScript file"
    unless $psfile[0] =~ /^%!PS-Adobe-(.*)/;

$line = $[;                                # Locate pages
for (@psfile) {
    if (/^%%Page:(.*)(\d+)$/) {
        push(@pages,$line);
        push(@labels,$1);
    }
    $line++;
}
die "This file contains no PostScript %%Page comments\n" if $#pages < $[;

$trailer = $#psfile;                       # Locate trailer
for (reverse(@psfile)) {
    last if /^%%Trailer/;
    $trailer--;
}

print @psfile[$[..$pages[0] - 1];          # Output prolog

$pageno = 1;                               # Output pages in reverse order
$to_line = $trailer - 1;
while ($from_line = pop(@pages)) {
    printf "%%%%Page:%s%d\n", pop(@labels), $pageno++;
    print @psfile[$from_line + 1 .. $to_line];
    $to_line = $from_line - 1;
}

print @psfile[$trailer .. $#psfile];       # Output trailer
__END__



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Gisle Aas               |  snail: Boks 114 Blindern, N-0314 Oslo, Norway
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