X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=x2p%2Fs2p.PL;h=73f67872de1bf098529d0431dce95daa723ed0bb;hb=d121ca8cbe925d3e532e9c845f6853715e75724a;hp=4f7293d4c23d37733fdd2edcf33dce5ae3d1cbf5;hpb=f70b6ff5dbae63778d9b1ac9a297c2d960e64cbf;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/x2p/s2p.PL b/x2p/s2p.PL
index 4f7293d..73f6787 100644
--- a/x2p/s2p.PL
+++ b/x2p/s2p.PL
@@ -12,11 +12,9 @@ use File::Basename qw(&basename &dirname);
 
 # This forces PL files to create target in same directory as PL file.
 # This is so that make depend always knows where to find PL derivatives.
-chdir(dirname($0));
-($file = basename($0)) =~ s/\.PL$//;
-$file =~ s/\.pl$//
-	if ($Config{'osname'} eq 'VMS' or
-	    $Config{'osname'} eq 'OS2');  # "case-forgiving"
+chdir dirname($0);
+$file = basename($0, '.PL');
+$file .= '.com' if $^O eq 'VMS';
 
 open OUT,">$file" or die "Can't create $file: $!";
 
@@ -26,10 +24,11 @@ print "Extracting $file (with variable substitutions)\n";
 # You can use $Config{...} to use Configure variables.
 
 print OUT <<"!GROK!THIS!";
-$Config{'startperl'}
-    eval 'exec perl -S \$0 "\$@"'
-	if 0;
+$Config{startperl}
+    eval 'exec $Config{perlpath} -S \$0 \${1+"\$@"}'
+	if \$running_under_some_shell;
 \$startperl = "$Config{startperl}";
+\$perlpath = "$Config{perlpath}";
 !GROK!THIS!
 
 # In the following, perl variables are not expanded during extraction.
@@ -40,6 +39,78 @@ print OUT <<'!NO!SUBS!';
 #
 # $Log:	s2p.SH,v $
 
+=head1 NAME
+
+s2p - Sed to Perl translator
+
+=head1 SYNOPSIS
+
+B<s2p [options] filename>
+
+=head1 DESCRIPTION
+
+I<S2p> takes a sed script specified on the command line (or from
+standard input) and produces a comparable I<perl> script on the
+standard output.
+
+=head2 Options
+
+Options include:
+
+=over 5
+
+=item B<-DE<lt>numberE<gt>>
+
+sets debugging flags.
+
+=item B<-n>
+
+specifies that this sed script was always invoked with a B<sed -n>.
+Otherwise a switch parser is prepended to the front of the script.
+
+=item B<-p>
+
+specifies that this sed script was never invoked with a B<sed -n>.
+Otherwise a switch parser is prepended to the front of the script.
+
+=back
+
+=head2 Considerations
+
+The perl script produced looks very sed-ish, and there may very well
+be better ways to express what you want to do in perl.  For instance,
+s2p does not make any use of the split operator, but you might want
+to.
+
+The perl script you end up with may be either faster or slower than
+the original sed script.  If you're only interested in speed you'll
+just have to try it both ways.  Of course, if you want to do something
+sed doesn't do, you have no choice.  It's often possible to speed up
+the perl script by various methods, such as deleting all references to
+$\ and chop.
+
+=head1 ENVIRONMENT
+
+S2p uses no environment variables.
+
+=head1 AUTHOR
+
+Larry Wall E<lt>F<larry@wall.org>E<gt>
+
+=head1 FILES
+
+=head1 SEE ALSO
+
+ perl	The perl compiler/interpreter
+ 
+ a2p	awk to perl translator
+
+=head1 DIAGNOSTICS
+
+=head1 BUGS
+
+=cut
+
 $indent = 4;
 $shiftwidth = 4;
 $l = '{'; $r = '}';
@@ -295,7 +366,7 @@ unless ($debug) {
 
     print &q(<<"EOT");
 :	$startperl
-:	eval 'exec perl -S \$0 \${1+"\$@"}'
+:	eval 'exec $perlpath -S \$0 \${1+"\$@"}'
 :		if \$running_under_some_shell;
 :	
 EOT