use Perl

• GCDs in a regex (Score:1)

  by JadeNB (9501)

  I was very proud of this recent substitution that implements the Euclidean algorithm: http://perlmonks.org/?node_id=804838 [perlmonks.org] It follows in the fine tradition of the regex primality test by using repeated capturing groups to perform division with remainder.
• My most common ones are pretty simple. (Score:1)

  by elliot (8136)

  perl -MSome::Module -e 0

  perl -E 'say foreach split ":", $ENV{PATH}' # Or other pathlike thing.

  ack --text -l '\bv1.2.3\b' | xargs perl -pi -e 's/\bv1\.2\.3\b/v1.2.4/g'

  Otherwise, it's mostly experiments; I prefer bash to a REPL.
• MetaSyntactic (Score:2)

  by domm (4030)

  ~$ perl -MAcme::MetaSyntactic=donmartin -E 'say metaname'
  KLINK

  Or, if I need several alternatives to boring values like 'foo':

  ~$ perl -MAcme::MetaSyntactic=any -E 'say metaname for 1..10'
  l5nas_parchan
  The_Living_Daylights
  sugar
  TO
  Nick
  Neptune
  Pigpen
  b romine
  Kyrano
  voyager

  But usually I prefere the donmartin theme
• Various one-liners from MNooning (Score:1)

  by mhn (7491)

  MNooning wrote:
  
  Here are some Windows one-liners. On Linux, use single quotes and forward slashes.
  Find the INC path that Perl sees when it starts up.
  >perl -e "print qq[INC = @INC\n];"
  INC = C:/Perl/site/lib C:/Perl/lib .
  
  Another way to find the INC path.
  perl -wle "print for @INC"
  C:/Perl/site/lib
  C:/Perl/lib
  
  Find out if a module is installed. If it is, no error messages will show.
  >perl -e "use Tk"
  
  Obtain the version of an installed module.
  >perl -MTk -e "print \"$Tk::VERSION\n\"
  804.0285
• Eval (Score:2)

  by Juerd (1796)

  Still my favorite is:

  perl -ple'$_=eval'

  It's a pure REPL. It evaluates every line from stdin and outputs whatever they evaluate to. It has many uses, but most of the time it's "just" a very powerful calculator.
• The awk features are rather nice (Score:1)

  by jjore (6662)

  I find I use -a rather alot for snippets like the following:

  dpkg -l | perl -lane 'print $F[1] if $F[1] =~ /ruby/'

  It's still useful for alternative delimiters. Pretending dpkg used tabs for delimiters, I'd add the parameter

  -F$'\t'

  It also find it's really helpful to got a proper handle on quoting whether in my shell or in perl. Often in a one-liner I'm using qq{} in perl to avoid messing with my shell's own use of ' or ". Occasionally I use bash's $'\t' syntax which lets me say things like

  perl -F$'\t'
• The cutest of them all (Score:1)

  by Aristotle (5147)

  Here’s a replacement for cat(1):

  perl -please somefile.txt