nroff-scan.pl: verifies nroff pages

... not used by any test yet but can be used stand-alone.

tests/nroff-scan.pl

+#!/usr/bin/env perl
+#***************************************************************************
+#                                  _   _ ____  _
+#  Project                     ___| | | |  _ \| |
+#                             / __| | | | |_) | |
+#                            | (__| |_| |  _ <| |___
+#                             \___|\___/|_| \_\_____|
+#
+# Copyright (C) 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at https://curl.haxx.se/docs/copyright.html.
+#
+# You may opt to use, copy, modify, merge, publish, distribute and/or sell
+# copies of the Software, and permit persons to whom the Software is
+# furnished to do so, under the terms of the COPYING file.
+#
+# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+# KIND, either express or implied.
+#
+###########################################################################
+#
+# scan nroff pages to find basic syntactic problems such as unbalanced \f
+# codes
+
+my $docsroot = $ARGV[0];
+
+if(!$docsroot || ($docsroot eq "-g")) {
+    print "Usage: nroff-scan.pl <docs root dir> [nroff files]\n";
+    exit;
+}
+
+
+shift @ARGV;
+
+my @f = @ARGV;
+
+my %manp;
+
+sub file {
+    my ($f) = @_;
+    open(F, "<$f") ||
+        die "no file";
+    my $line = 1;
+    while(<F>) {
+        chomp;
+        my $l = $_;
+        while($l =~ s/\\f(.)([^ ]*)\\f(.)//) {
+            my ($pre, $str, $post)=($1, $2, $3);
+            if($post ne "P") {
+                print STDERR "error: $f:$line: missing \\fP after $str\n";
+            }
+            if($str =~ /(curl([^ ]*))\(3\)/i) {
+                my $man = "$1.3";
+                if($manp{$man}) {
+                    ;
+                }
+                elsif(-r "$docsroot/$man" ||
+                      -r "$docsroot/libcurl/$man" ||
+                      -r "$docsroot/libcurl/opts/$man") {
+                    $manp{$man}=1;
+                }
+                else {
+                    print STDERR "error: $f:$line: refering to non-existing man page $man\n";
+                }
+            }
+        }
+        if($l =~ /(curl([^ ]*)\(3\))/i) {
+            print STDERR "error: $f:$line: non-referencing $1\n";
+        }
+        $line++;
+    }
+    close(F);
+}
+
+foreach my $f (@f) {
+    file($f);
+}