pbot/applets/c99std.pl

#!/usr/bin/env perl

# SPDX-FileCopyrightText: 2021 Pragmatic Software <pragma78@gmail.com>
# SPDX-License-Identifier: MIT

use warnings;
use strict;

my $debug = 0;

# for paragraphs
my $USER_SPECIFIED    = 1;
my $RESULTS_SPECIFIED = 2;

my $search = join ' ', @ARGV;

if (not length $search) {
    print
      "Usage: c99std [-list] [-n#] [-section <section>] [search text] -- 'section' must be in the form of X.YpZ where X and Y are section/chapter and, optionally, pZ is paragraph. If both 'section' and 'search text' are specified, then the search space will be within the specified section. You may use -n # to skip to the #th match. To list only the section numbers containing 'search text', add -list.\n";
    exit 0;
}

my ($section, $paragraph, $section_specified, $paragraph_specified, $match, $list_only, $list_titles);

$section_specified   = 0;
$paragraph_specified = 0;

if ($search =~ s/-section\s*([A-Z0-9\.p]+)//i or $search =~ s/\b([A-Z0-9]+\.[0-9\.p]+)//i) {
    $section = $1;

    if ($section =~ s/p(\d+)//i) {
        $paragraph           = $1;
        $paragraph_specified = $USER_SPECIFIED;
    } else {
        $paragraph = 1;
    }

    $section = "$section." if $section =~ m/^[A-Z0-9]+$/i;

    $section_specified = 1;
}

if   ($search =~ s/-n\s*(\d+)//) { $match = $1; }
else                             { $match = 1; }

if ($search =~ s/-list//i) {
    $list_only   = 1;
    $list_titles = 1;    # Added here instead of removing -titles option
}

if ($search =~ s/-titles//i) {
    $list_only   = 1;
    $list_titles = 1;
}

$search =~ s/^\s+//;
$search =~ s/\s+$//;

if (not defined $section) {
    $section   = "1.";
    $paragraph = 1;
}

if ($list_only and not length $search) {
    print "You must specify some search text to use with -list.\n";
    exit 0;
}

open FH, "<n1256.out" or die "Could not open n1256: $!";
my @contents = <FH>;
close FH;

my $text = join '', @contents;
$text =~ s/\r//g;

my $result;
my $found_section       = "";
my $found_section_title = "";
my $section_title;
my $found_paragraph;
my $found   = 0;
my $matches = 0;
my $this_section;
my $comma = "";

if ($list_only) { $result = "Sections containing '$search':\n    "; }

my $qsearch = quotemeta $search;
$qsearch =~ s/\\ / /g;
$qsearch =~ s/\s+/\\s+/g;

while ($text =~ m/^\s{0,4}([0-9A-Z]+\.[0-9\.]*)/msg) {
    $this_section = $1;

    print "----------------------------------\n" if $debug >= 2;
    print "Processing section [$this_section]\n" if $debug;

    if ($section_specified and $this_section !~ m/^$section/i) {
        print "No section match, skipping.\n" if $debug >= 4;
        next;
    }

    my $section_text;

    if ($text =~ m/(.*?)^(?=\s{0,4}(?!FOOTNOTE)[0-9A-Z]+\.)/msg) { $section_text = $1; }
    else {
        print "No section text, end of file marker found.\n" if $debug >= 4;
        last;
    }

    if ($section =~ /FOOTNOTE/i) {
        $section_text =~ s/^\s{4}//ms;
        $section_text =~ s/^\s{4}FOOTNOTE.*//msi;
        $section_text =~ s/^\d.*//ms;
    } elsif ($section_text =~ m/(.*?)$/msg) {
        $section_title = $1 if length $1;
        $section_title =~ s/^\s+//;
        $section_title =~ s/\s+$//;
    }

    print "$this_section [$section_title]\n" if $debug >= 2;

    while ($section_text =~ m/^(\d+)\s(.*?)^(?=\d)/msgic or $section_text =~ m/^(\d+)\s(.*)/msgi) {
        my $p = $1;
        my $t = $2;

        print "paragraph $p: [$t]\n" if $debug >= 3;

        if ($paragraph_specified == $USER_SPECIFIED and not length $search and $p == $paragraph) {
            $result              = $t if not $found;
            $found_paragraph     = $p;
            $found_section       = $this_section;
            $found_section_title = $section_title;
            $found               = 1;
            last;
        }

        if (length $search) {
            eval {
                if ($t =~ m/\b$qsearch\b/mis or $section_title =~ m/\b$qsearch\b/mis) {
                    $matches++;
                    if ($matches >= $match) {
                        if ($list_only) {
                            $result .= sprintf("%s%-15s", $comma, $this_section . "p" . $p);
                            $result .= " $section_title" if $list_titles;
                            $comma = ",\n    ";
                        } else {
                            if (not $found) {
                                $result              = $t;
                                $found_section       = $this_section;
                                $found_section_title = $section_title;
                                $found_paragraph     = $p;
                                $paragraph_specified = $RESULTS_SPECIFIED;
                            }
                            $found = 1;
                        }
                    }
                }
            };

            if ($@) {
                print "Error in search regex; you may need to escape characters such as *, ?, ., etc.\n";
                exit 0;
            }
        }
    }

    last if $found && $paragraph_specified == $USER_SPECIFIED;

    if ($paragraph_specified == $USER_SPECIFIED) {
        if   (length $search) { print "No such text '$search' found within paragraph $paragraph of section $section of n1256.\n"; }
        else                  { print "No such paragraph $paragraph in section $section of n1256.\n"; }
        exit 0;
    }

    if (defined $section_specified and not length $search) {
        $found               = 1;
        $found_section       = $this_section;
        $found_section_title = $section_title;
        $found_paragraph     = $paragraph;
        $result              = $section_text;
        last;
    }
}

if (not $found and $comma eq "") {
    $search =~ s/\\s\+/ /g;
    if ($section_specified) {
        print "No such text '$search' found within section '$section' in C99 Draft Standard (n1256).\n" if length $search;
        print "No such section '$section' in C99 Draft Standard (n1256).\n"                             if not length $search;
        exit 0;
    }

    print "No such section '$section' in C99 Draft Standard (n1256).\n"   if not length $search;
    print "No such text '$search' found in C99 Draft Standard (n1256).\n" if length $search;
    exit 0;
}

$result =~ s/$found_section_title// if length $found_section_title;
$result =~ s/^\s+//;
$result =~ s/\s+$//;

=cut
$result =~ s/\s+/ /g;
$result =~ s/[\n\r]/ /g;
=cut

if ($matches > 1 and not $list_only) { print "Displaying $match of $matches matches: "; }

if ($comma eq "") {
    print "http://www.iso-9899.info/n1256.html\#$found_section";
    print "p" . $found_paragraph if $paragraph_specified;
    print "\n\n";
    print "[", $found_section_title, "]\n\n" if length $found_section_title;
}

$result =~ s/\s*Constraints\s*$//;
$result =~ s/\s*Semantics\s*$//;
$result =~ s/\s*Description\s*$//;
$result =~ s/\s*Returns\s*$//;
$result =~ s/\s*Runtime-constraints\s*$//;
$result =~ s/\s*Recommended practice\s*$//;

print "$result\n";