Commands tagged perl (182)

  • In this example, file contains five columns where first column is text. Variance is calculated for columns 2 - 5 by using perl module Statistics::Descriptive. There are many more statistical functions available in the module. Show Sample Output


    1
    perl -MStatistics::Descriptive -alne 'my $stat = Statistics::Descriptive::Full->new; $stat->add_data(@F[1..4]); print $stat->variance' filename
    alperyilmaz · 2010-04-02 21:16:12 0
  • This method will also convert mac line endings.


    3
    perl -pi -e 's/\r\n?/\n/g'
    putnamhill · 2010-03-18 17:48:16 2
  • Using perl you can search for patterns spanning several lines, a thing that grep can't do. Append the list of files to above command or pipe a file through it, just as with regular grep. If you add the 's' modifier to the regex, the dot '.' also matches line endings, useful if you don't known how many lines you need are between parts of your pattern. Change '*' to '*?' to make it greedy, that is match only as few characters as possible. See also http://www.commandlinefu.com/commands/view/1764/display-a-block-of-text-with-awk to do a similar thing with awk. Edit: The undef has to be put in a begin-block, or a match in the first line would not be found.


    7
    perl -ne 'BEGIN{undef $/}; print "$ARGV\t$.\t$1\n" if m/(first line.*\n.*second line)/mg'
    hfs · 2010-03-18 15:46:10 1
  • Converts reserved characters in a URI to their percent encoded counterparts. Alternate python version: echo "$url" | python -c 'import sys,urllib;print urllib.quote(sys.stdin.read().strip())' Show Sample Output


    7
    echo "$url" | perl -MURI::Escape -ne 'chomp;print uri_escape($_),"\n"'
    eightmillion · 2010-02-13 00:44:48 0
  • This shell function grabs the weather forecast for the next 24 to 48 hours from weatherunderground.com. Replace <YOURZIPORLOCATION> with your zip code or your "city, state" or "city, country", then calling the function without any arguments returns the weather for that location. Calling the function with a zip code or place name as an argument returns the weather for that location instead of your default. To add a bit of color formatting to the output, use the following instead: weather(){ curl -s "http://api.wunderground.com/auto/wui/geo/ForecastXML/index.xml?query=${@:-<YOURZIPORLOCATION>}"|perl -ne '/<title>([^<]+)/&&printf "\x1B[0;34m%s\x1B[0m: ",$1;/<fcttext>([^<]+)/&&print $1,"\n"';} Requires: perl, curl Show Sample Output


    7
    weather(){ curl -s "http://api.wunderground.com/auto/wui/geo/ForecastXML/index.xml?query=${@:-<YOURZIPORLOCATION>}"|perl -ne '/<title>([^<]+)/&&printf "%s: ",$1;/<fcttext>([^<]+)/&&print $1,"\n"';}
    eightmillion · 2010-02-10 01:23:39 8
  • This version works on Mac (avoids grep -P, adding a sed step instead, and invokes /usr/bin/perl with full path in case you have another one installed). Still requires that you install perl module HTML::Entities ? here's how: http://www.perlmonks.org/?node_id=640489


    7
    define(){ local y="$@";curl -sA"Opera" "http://www.google.com/search?q=define:${y// /+}"|grep -Eo '<li>[^<]+'|sed 's/^<li>//g'|nl|/usr/bin/perl -MHTML::Entities -pe 'decode_entities($_)';}
    gthb · 2010-01-30 13:08:03 1
  • This function takes a word or a phrase as arguments and then fetches definitions using Google's "define" syntax. The "nl" and perl portion isn't strictly necessary. It just makes the output a bit more readable, but this also works: define(){ local y="$@";curl -sA"Opera" "http://www.google.com/search?q=define:${y// /+}"|grep -Po '(?<=<li>)[^<]+';} If your version of grep doesn't have perl compatible regex support, then you can use this version: define(){ local y="$@";curl -sA"Opera" "http://www.google.com/search?q=define:${y// /+}"|grep -Eo '<li>[^<]+'|sed 's/<li>//g'|nl|perl -MHTML::Entities -pe 'decode_entities($_)' 2>/dev/null;} Show Sample Output


    18
    define(){ local y="$@";curl -sA"Opera" "http://www.google.com/search?q=define:${y// /+}"|grep -Po '(?<=<li>)[^<]+'|nl|perl -MHTML::Entities -pe 'decode_entities($_)' 2>/dev/null;}
    eightmillion · 2010-01-29 05:01:11 4
  • Prerequisites: module Pod::Webserver installed. You can install it typing: sudo perl -MCPAN -e 'install Pod::Webserver' You can replace elinks with your fav browser. For FF: podwebserver& sleep 2; firefox -remote 'openurl( http://127.0.0.1:8020/, new-tab )' If you have Firefox open, this will pop-up the index web in a new tab.


    5
    podwebserver& sleep 2; elinks 'http://127.0.0.1:8020'
    vlan7 · 2010-01-27 10:57:34 4
  • This is a command that I find myself using all the time. It works like regular grep, but returns the paragraph containing the search pattern instead of just the line. It operates on files or standard input. grepp <PATTERN> <FILE> or <SOMECOMMAND> | grepp <PATTERN> Show Sample Output


    13
    grepp() { [ $# -eq 1 ] && perl -00ne "print if /$1/i" || perl -00ne "print if /$1/i" < "$2";}
    eightmillion · 2010-01-12 04:30:15 5
  • print the lines of a file in randomized order Show Sample Output


    0
    perl -wl -e '@f=<>; for $i (0 .. $#f) { $r=int rand ($i+1); @f[$i, $r]=@f[$r,$i] if ($i!=$r); } chomp @f; print join $/, @f;' try.txt
    JohnGH · 2009-12-21 21:15:55 0
  • If you want all the URLs from all the sessions, you can use : perl -lne 'print for /url":"\K[^"]+/g' ~/.mozilla/firefox/*/sessionstore.js Thanks to tybalt89 ( idea of the "for" statement ). For perl purists, there's JSON and File::Slurp modules, buts that's not installed by default.


    0
    perl -lne 'print for /url":"\K[^"]+/g' $(ls -t ~/.mozilla/firefox/*/sessionstore.js | sed q)
    sputnick · 2009-12-14 00:51:54 0
  • Thanks to comment if that works or not... If you have already typed that snippet or you know you already have IO::Interface::Simple perl module, you can type only the last command : perl -e 'use IO::Interface::Simple; my $ip=IO::Interface::Simple->new($ARGV[0]); print $ip->address,$/;' <INTERFACE> ( The first perl command will install the module if it's not there already... )


    1
    x=IO::Interface::Simple; perl -e 'use '$x';' &>/dev/null || cpan -i "$x"; perl -e 'use '$x'; my $ip='$x'->new($ARGV[0]); print $ip->address,$/;' <INTERFACE>
    sputnick · 2009-12-13 02:23:40 6

  • -3
    perl -e 'use Date::Calc qw(Today Week_Number); $weekn = Week_Number(Today); print "$weekn\n"'
    imsaar · 2009-12-01 20:56:13 0
  • don't have to be that complicated


    -1
    cho "(Something like http://foo.com/blah_blah)" | awk '{for(i=1;i<=NF;i++){if($i~/^(http|ftp):\/\//)print $i}}'
    unixmonkey7109 · 2009-11-28 03:31:41 3
  • From http://daringfireball.net/2009/11/liberal_regex_for_matching_urls Thought it would be useful to commandlinefuers. Show Sample Output


    0
    echo "(Something like http://foo.com/blah_blah)" | grep -oP "\b(([\w-]+://?|www[.])[^\s()<>]+(?:\([\w\d]+\)|([^[:punct:]\s]|/)))"
    matthewbauer · 2009-11-28 00:41:57 0

  • 5
    perl -pe 's/%([0-9a-f]{2})/sprintf("%s", pack("H2",$1))/eig'
    putnamhill · 2009-11-25 14:32:50 1
  • A shell function using perl to easily convert Unix-time to text. Put in in your ~/.bashrc or equivalent. Tested on Linux / Solaris Bourne, bash and zsh. using perl 5.6 and higher. (Does not require GNU date like some other commands) Show Sample Output


    1
    utime(){ perl -e "print localtime($1).\"\n\"";}
    MoHaG · 2009-11-06 12:58:10 0
  • dpigs is in the package debian-goodies (debian/ubuntu)


    11
    dpigs
    xrm0 · 2009-10-26 20:38:17 0
  • List packages and their disk usage in decreasing order. This uses the "Installed-Size" from the package metadata. It may differ from the actual used space, because e.g. data files (think of databases) or log files may take additional space. Show Sample Output


    0
    perl -ne '$pkg=$1 if m/^Package: (.*)/; print "$1\t$pkg\n" if m/^Installed-Size: (.*)/;' < /var/lib/dpkg/status | sort -rn | less
    hfs · 2009-10-19 12:55:59 1

  • -1
    perl -i -ne 'print uc $_' $1
    rbs · 2009-10-15 16:59:38 0
  • Place the regular expression you want to validate between the forward slashes in the eval block. Show Sample Output


    4
    perl -we 'my $regex = eval {qr/.*/}; die "$@" if $@;'
    tlacuache · 2009-10-13 21:50:47 1
  • same, except it works on any OS with Perl installed. DOS, Windose, whatever


    -2
    perl -pi -e 's/([[:lower:]]+)/uc $1/gsex' file
    linuxrawkstar · 2009-10-08 14:18:50 0
  • Uses curl to download page of membership of US Congress. Use sed to strip HTML then perl to print a line starting with two tabs (a line with a representative) Show Sample Output


    -1
    curl "http://www.house.gov/house/MemberWWW.shtml" 2>/dev/null | sed -e :a -e 's/<[^>]*>//g;/</N;//ba' | perl -nle 's/^\t\t(.*$)/ $1/ and print;'
    drewk · 2009-09-24 23:37:36 0
  • random(6) - random lines from a file or random numbers


    3
    random -f <file>
    haplo · 2009-09-24 19:15:58 4
  • change the *.avi to whatever you want to match, you can remove it altogether if you want to check all files.


    10
    find -type f -name "*.avi" -print0 | xargs -0 mplayer -vo dummy -ao dummy -identify 2>/dev/null | perl -nle '/ID_LENGTH=([0-9\.]+)/ && ($t +=$1) && printf "%02d:%02d:%02d\n",$t/3600,$t/60%60,$t%60' | tail -n 1
    syssyphus · 2009-09-24 15:50:39 4
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