From ba3fa50c1e7bbef1c877af654276d2e131afd07a Mon Sep 17 00:00:00 2001
From: ian <ian>
Date: Wed, 18 Jul 2001 20:31:50 +0000
Subject: [PATCH] conditionals

---
 gpt | 93 ++++++++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 65 insertions(+), 28 deletions(-)

diff --git a/gpt b/gpt
index 7fca9c5..d87e789 100755
--- a/gpt
+++ b/gpt
@@ -19,9 +19,22 @@ use IO::File;
 
 open DEBUG, ">&4";
 
-$fh= new IO::Handle;
-$fh->fdopen(fileno(STDIN),'r') or die;
-process_fh($fh,'<standard input>');
+$fn= '<command line>';
+if (!@main::ARGV) {
+    $lno= '<empty>';
+    $fh= new IO::Handle;
+    $fh->fdopen(fileno(STDIN),'r') or err("fdopen stdin: $!");
+    process_fh($fh,'<standard input>');
+    $fh->close or err("close stdin: $!\n");
+} else {
+    for ($i=0; $i<@main::ARGV; $i++) {
+	$lno= '<arg#'.($i+1).'>';
+	$value= $main::ARGV[$i];
+	$fh= new IO::File $value,'r' or err("cannot open file \`$value': $!");
+	process_fh($fh,$value);
+	$fh->close or err("gpt: cannot close file \`$value': $!");
+    }
+}
 close STDOUT or die "gpt: close stdout: $!\n";
 exit 0;
 
@@ -38,9 +51,24 @@ sub add_text ($) {
     if (@oplist) { $substr.=$str; }
     else { output($str); }
 }
-		
+
+sub eval_expr () {		
+    my ($value);
+    $@='';
+    print DEBUG "E $fn:$lno:e\`$expr'\n";
+    $value= do {
+	package main;
+	eval $GenericPrepTemplate::expr;
+    };
+    if (length $@) {
+	chomp $@; err("error: $@");
+    }
+    print DEBUG "E $fn:$lno:v\`$value'\n";
+    $value;
+}
+
 sub process_input () {
-    my ($esc,$top,$want,$fh,$value);
+    my ($esc,$top,$want,$fh,$value,$wasyes);
     while (length $l) {
 	print DEBUG "L $fn:$lno:",join('',@oplist),
 	            ":`$l' e\`$expr' s\`$substr'\n";
@@ -48,26 +76,16 @@ sub process_input () {
 	    if ($l =~ m/(.)\@\@/m || $l =~ m/^()\@\@/m) {
 		($to,$op,$esc,$l) = ($`,$1,$&,$');
 		add_perl($to);
-		if ($op =~ m/[ 0-9a-zA-Z_\;\)\}]/ || $op eq '') {
+		if ($op =~ m/[ 0-9a-zA-Z_\;\)\}?]/ || $op eq '') {
 		    $top= pop @oplist;
 		    if (!@oplist) {
 			# And evaluate.
-			$expr.= $op;
-			$@='';
-			print DEBUG "E $fn:$lno:e\`$expr'\n";
-			$value= do {
-			    package main;
-			    eval $GenericPrepTemplate::expr;
-			};
-			if (length $@) {
-			    chomp $@; err("error: $@");
-			}
-			print DEBUG "E $fn:$lno:v\`$value'\n";
+			$expr.= $op unless $op =~ m/[?]/;
+			$value= eval_expr();
 			if ($top eq '<') {
-			    $fh= new IO::File $value,'r'
-				or err("cannot open file \`$value': $!");
-			    process_fh($fh,$value);
-			    $fh->close;
+			    process_file($value);
+			} elsif ($top eq '?') {
+			    push @oplist, '?',':;'.!!$value;
 			} elsif ($top ne '-') {
 			    output($value);
 			}
@@ -89,16 +107,35 @@ sub process_input () {
 	    if ($l =~ m/\@\@(.|\n)/) {
 		($to,$op,$esc,$l) = ($`,$1,$&,$');
 		add_text($to);
-		if ($op =~ m/[-< \$]/) {
+		if ($op =~ m/[-< \$?]/) {
 		    $substr.= $esc if @oplist;
 		    push @oplist, $op;
-		} elsif ($op =~ m/[\)\}]/) {
+		} elsif ($op =~ m/[\)\}\;\:]/) {
 		    err("unmatched closing \@\@$op") unless @oplist;
-		    my ($want);
-		    $want= $oplist[$#oplist] eq '(' ? ')' : '}';
-		    err("found \@\@$op but wanted \@\@$want")
-			unless $want eq $op;
-		    pop @oplist;
+		    $want= pop @oplist;
+		    if ($want =~ y/({/)}/) {
+			$wasyes=-1;
+			err("found \@\@$op but wanted \@\@$want")
+			    unless $want eq $op;
+		    } elsif ($want =~ m/^([:;]+)(1?)$/) {
+			($want,$wasyes)=($1,$2);
+			err("found \@\@$op where not expected (wanted ".
+			    join(' or ', map { "\@\@$_" } split //, $want).")")
+			    unless $op =~ m/^[$want]$/;
+			'?' eq pop @oplist or die;
+			if ($wasyes) {
+			    local ($l) = ($substr);
+			    local ($substr,$expr,$to,$op);
+			    process_input();
+			};
+			$substr='';
+			$esc='';
+			if ($op eq ':') {
+			    push @oplist, '?',';'.!$wasyes;
+			}
+		    } else {
+			die "internal /$want/ /$op/";
+		    }
 		    if (@oplist==1) {
 			# Just finished a substr.
 			$substri++;
-- 
2.30.2