curl/docs/examples/version-check.pl

#!/usr/bin/env perl

open(S, "<../libcurl/symbols-in-versions") || die;

my %doc;
my %rem;
while(<S>) {
    if(/(^CURL[^ \n]*) *(.*)/) {
        my ($sym, $rest)=($1, $2);
        my @a=split(/ +/, $rest);

        $doc{$sym}=$a[0]; # when it was introduced

        if($a[2]) {
            # this symbol is documented to have been present the last time
            # in this release
            $rem{$sym}=$a[2];
        }
    }

}

close(S);

sub age {
    my ($ver)=@_;

    my @s=split(/\./, $ver);
    return $s[0]*10000+$s[1]*100+$s[2];
}

my %used;
open(C, "<$ARGV[0]") || die;

while(<C>) {
    if(/\W(CURL[_A-Z0-9v]+)\W/) {
        #print "$1\n";
        $used{$1}++;
    }
}

close(C);

sub sortversions {
    my $r = age($doc{$a}) <=> age($doc{$b});
    if(!$r) {
        $r = $a cmp $b;
    }
    return $r;
}

my @recent = reverse sort sortversions keys %used;

# the most recent symbol
my $newsym = $recent[0];
# the most recent version
my $newver = $doc{$newsym}; 

print "The scanned source uses these symbols introduced in $newver:\n";

for my $w (@recent) {
    if($doc{$w} eq $newver) {
        printf "  $w\n";
        next;
    }
    last;
}