brian d foy

A friend showed me the following line, that I find most convenient as a sysadmin. It's always in my .bashrc ever since:

function sshdel () {

    perl -i -n -e "print unless (\$. == $1)" ~/.ssh/known_hosts;

}

Also, I've picked these up, don't remember exactly where:

function google () {
    u=`perl -MURI::Escape -wle 'print "http://google.com/search?q=".
    uri_escape(join " ",  @ARGV)' $@`
    w3m -no-mouse -F $u
}

function scpan () {

    u=`perl -MURI::Escape -wle 'print "http://search.cpan.org/search?query=".

        uri_escape(join " ",  @ARGV) ."&mode=module&n=100"' $@`

    w3m -no-mouse -F $u

}

I wrote a post about my one-liner file.

Of those the only ones that I use regularly are:

# Set an xterm title

perl -e 'print "\c[];@ARGV\a"' Some title here

# Find the version number of a module

perl -le 'eval "require $ARGV[0]" and print $ARGV[0]->VERSION' Some::Module

I should add that the xterm one-liner is dependent on environmental variables or processes not overriding the title.

Not technically a oneliner because it's not standalone code, but one that I like anyway: cartesian product in one tweet. With the air let back into it, it's:

use List::Util qw(reduce);
sub list_product {
    reduce {
       [ map {
           my $i = $_; # Save outer $_
           map [ @$_, $i ], @$a
       } @$b ]
   } [[]], @_
}

The upshot of which is that it gives you the cartesian product in an arbitrary number of dimensions, e.g. list_product [1, 2, 3], ['a', 'b'] gets you

(
    [1, 'a'],
    [1, 'b'],
    [2, 'a'],
    [2, 'b'],
    [3, 'a'],
    [3, 'b'],
)

The Perl calculator:

The Poor-Man's Grep (for Winodws):

Replace PATTERN with the regular expression pattern to search for.

This one-liner analyzes the linguistic properties of a piece of English text. It's useful for figuring out the piece's complexity, so you can temper it for various audience types:

perl -MLingua::EN::Fathom -le
    "print Lingua::EN::Fathom->new->analyse_file(shift)->report;"

Kinda long for a one-liner, but I use it often, so it deserved an entry in my .bash/functions file.

# expand tiny-url
function exturl {
    perl -MLWP::UserAgent -le 'print LWP::UserAgent
                                      ->new(requests_redirectable => [])
                                      ->get(shift)
                                      ->header("Location")' "$1"
}

# Remove the first column of a file

perl -nale 'shift@F;print"@F"'

Nothing fancy, but it's handy when you want to pull IP addresses out of log files

cat /var/log/messages|perl -e 'while (>) {/(\d+\.\d+\.\d+\.\d+)/ && print "$1\n"};'