Commands using perl (369)

  • 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 $1,"\n"';}
    eightmillion · 2010-02-10 01:23:39 16
  • Converts reserved characters in a URI to their percent encoded counterparts. Alternate python version: echo "$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 32
  • 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 32
  • Works only if modules are installed "the right way"


    7
    perl -MExtUtils::Installed -e '$inst = ExtUtils::Installed->new(); @modules = $inst->modules(); print join("\n", @modules);'
    braak · 2010-07-20 15:47:32 8
  • syntax follows regular command line expression. example: let's say you have a directory (with subdirs) that has say 4000 .php files. All of these files were made via script, but uh-oh, there was a typo! if the typo is "let's go jome!" but you meant it to say "let's go home!" find . -name "*.php" | xargs perl -pi -e "s/let\'s\ go\ jome\!/let\'s\ go\ home\!/g" all better :) multiline: find . -name "*.php" | xargs perl -p0777i -e 's/knownline1\nknownline2/replaced/m' indescriminate line replace: find ./ -name '*.php' | xargs perl -pi -e 's/\".*$\"/\new\ line\ content/g' Show Sample Output


    6
    find . -name "*.txt" | xargs perl -pi -e 's/old/new/g'
    neztach · 2009-02-06 00:28:03 21
  • Find all files that contain string XXX in them, change the string from XXX to YYY, make a backup copy of the file and save a list of files changed in /tmp/fileschanged.


    6
    find . -type f -exec grep -l XXX {} \;|tee /tmp/fileschanged|xargs perl -pi.bak -e 's/XXX/YYY/g'
    drossman · 2009-02-16 02:55:23 59

  • 6
    nmap -sS -O -oX /tmp/nmap.xml 10.1.1.0/24 -v -v && perl nmap2nagios.pl -v -r /tmp/10net.xml -o /etc/nagios/10net.cfg
    scubacuda · 2009-02-19 18:42:37 8
  • Finds all directories containing more than 99MB of files, and prints them in human readable format. The directories sizes do not include their subdirectories, so it is very useful for finding any single directory with a lot of large files. Show Sample Output


    6
    du -hS / | perl -ne '(m/\d{3,}M\s+\S/ || m/G\s+\S/) && print'
    Alioth · 2009-03-25 18:06:53 5

  • 6
    perl -lne '$l{$_}=length;END{for(sort{$l{$a}<=>$l{$b}}keys %l){print}}' < /usr/share/dict/words | tail
    grokskookum · 2009-09-10 14:49:03 3
  • Cool but useless. Show Sample Output


    6
    perl -nle 'printf "%0*v8b\n"," ",$_;'
    forcefsck · 2011-01-21 09:20:54 6
  • I use this in my bashrc to expand hosts defined in ~/.ssh/config: function _ssh_completion() { perl -ne 'print "$1 " if /^Host (.+)$/' ~/.ssh/config } complete -W "$(_ssh_completion)" ssh Here's a great article on how to setup your own ~/.ssh/config: http://blogs.perl.org/users/smylers/2011/08/ssh-productivity-tips.html


    6
    perl -ne 'print "$1 " if /^Host (.+)$/' ~/.ssh/config
    bashrc · 2011-08-21 14:51:20 7

  • 5
    u=`curl -d 'dl.start=Free' $(curl $1|perl -wpi -e 's/^.*"(http:\/\/rs.*)" method.*$/$1/'|egrep '^http'|head -n1)|grep "Level(3) \#2"|perl -wpi -e 's/^.*(http:\/\/rs[^\\\\]*).*$/$1/'`;sleep 60;wget $u
    fel1x · 2009-04-01 20:14:41 6
  • Mouse around the title of this item, and note that your cookies are being logged to the console. If I were evil, I could instead send everyone's cookies to my site, and then post up-votes on all my submissions using their cookies, and try to delete every other submission, until clfu was completely pwned by me, redirecting people to malware and porn sites, and so on. Update - now fixed.


    5
    perl -pi -e 's/<a href="#" onmouseover="console.log('xss! '+document.cookie)" style="position:absolute;height:0;width:0;background:transparent;font-weight:normal;">xss</a>/<\/a>/g'
    isaacs · 2009-07-08 22:26:15 28

  • 5
    perl -ne 'split /,/ ; $a+= $_[3]; END {print $a."\n";}' -f ./file.csv
    ioggstream · 2009-08-07 09:35:52 3
  • 'jot' does not come with most *nix distros, so we need to use seq to make it work. This version tested good on Fedora 11.


    5
    for x in `seq 0 25 $(curl "http://www.commandlinefu.com/commands/browse"|grep "Terminal - All commands" |perl -pe 's/.+(\d+),(\d+).+/$1$2/'|head -n1)`; do curl "http://www.commandlinefu.com/commands/browse/sort-by-votes/plaintext/$x" ; done > a.txt
    SuperFly · 2009-08-27 11:02:53 7
  • In this example the command "somecommand" will be executed and sent a SIGALARM signal if it runs for more than 10 seconds. It uses the perl alarm function. It's not 100% accurate on timing, but close enough. I found this really useful when executing scripts and commands that I knew might hang E.g. ones that connect to services that might not be running. Importantly this can be used within a sequential script. The command will not release control until either the command completes or the timeout is hit. Show Sample Output


    5
    perl -e "alarm 10; exec @ARGV" "somecommand"
    jgc · 2009-09-23 12:03:55 9

  • 5
    perl -MCPAN -e 'CPAN::Shell->install(CPAN::Shell->r)'
    grokskookum · 2009-09-24 03:27:12 4
  • Place the regular expression you want to validate between the forward slashes in the eval block. Show Sample Output


    5
    perl -we 'my $regex = eval {qr/.*/}; die "$@" if $@;'
    tlacuache · 2009-10-13 21:50:47 10

  • 5
    perl -pe 's/%([0-9a-f]{2})/sprintf("%s", pack("H2",$1))/eig'
    putnamhill · 2009-11-25 14:32:50 38
  • First we accept a socket and fork the server. Then we overload the new socket as a code ref. This code ref takes one argument, another code ref, which is used as a callback. The callback is called once for every line read on the socket. The line is put into $_ and the socket itself is passed in to the callback. Our callback is scanning the line in $_ for an HTTP GET request. If one is found it parses the file name into $1. Then we use $1 to create an new IO::All file object... with a twist. If the file is executable("-x"), then we create a piped command as our IO::All object. This somewhat approximates CGI support. Whatever the resulting object is, we direct the contents back at our socket which is in $_[0].


    5
    perl -MIO::All -e 'io(":8080")->fork->accept->(sub { $_[0] < io(-x $1 ? "./$1 |" : $1) if /^GET \/(.*) / })'
    Neo23x0 · 2010-03-31 15:03:55 8
  • This will generate 3 paragraphs with random text. Change the 3 to any number. Show Sample Output


    5
    lynx -source http://www.lipsum.com/feed/xml?amount=3|perl -p -i -e 's/\n/\n\n/g'|sed -n '/<lipsum>/,/<\/lipsum>/p'|sed -e 's/<[^>]*>//g'
    houghi · 2010-04-26 17:26:44 5
  • Safe for whitespaces in names.


    5
    dpkg -L iptables | perl -lne 'print if -f && -x'
    depesz · 2010-10-30 15:47:51 7
  • Using tail to follow and standard perl to count and print the lps when lines are written to the logfile.


    5
    tail -f /var/log/logfile|perl -e 'while (<>) {$l++;if (time > $e) {$e=time;print "$l\n";$l=0}}'
    madsen · 2011-06-21 10:28:26 7

  • 4
    find . -type d | perl -nle 'print s,/,/,g," $_"' | sort -n | tail
    sirhc · 2009-02-23 22:52:07 5
  • When Ldapsearch queries an Active directory server, all the dates are shown using a timestamp of 18 digits. This perl regexp decodes them in a more human friendly notation. 11644473600 corresponds to some microsoft epoch. Show Sample Output


    4
    ldapsearch -v -H ldap://<server> -x -D cn=<johndoe>,cn=<users>,dc=<ourdomain>,dc=<tld> -w<secret> -b ou=<lazystaff>,dc=<ourdomain>,dc=<tld> -s sub sAMAccountName=* '*' | perl -pne 's/(\d{11})\d{7}/"DATE-AD(".scalar(localtime($1-11644473600)).")"/e'
    flux · 2009-04-22 00:57:34 5
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Get the full path of a bash script's Git repository head.
Rather than complicated and fragile paths relative to a script like "../../other", this command will retrieve the full path of the file's repository head. Safe with spaces in directory names. Works within a symlinked directory. Broken down: $cd "$(dirname "${BASH_SOURCE[0]}")" temporarily changes directories within this expansion. Double quoted "$(dirname" and ")" with unquoted ${BASH_SOURCE[0]} allows spaces in the path. $git rev-parse --show-toplevel gets the full path of the repository head of the current working directory, which was temporarily changed by the "cd".

Define Google Chrome urpmi media source for Mandriva/Mageia (works for both 32-bit and 64-bit systems)
This command adds a urpmi media source called "google-chrome" to the urpmi configuration on Mandriva or Mageia. Needs to be run as root. We specify the option "--update" so that when Google provides a newer version of Google Chrome web browser in their download system then running a system update (eg: "urpmi --auto-update") will result in our copy of Google Chrome getting updated (along with any other Mandriva/Mageia pending updates). To install Google Chrome from this source, use: urpmi google-chrome-stable #install Google chrome web browser

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

kill all process that belongs to you
This will probably kill any user sessions and/or ssh connections to other servers you might have active.

convert strings toupper/tolower with tr

return a titlecased version of the string
Needs Bash4. Found at http://stackoverflow.com/questions/2264428/converting-string-to-lower-case-in-bash-shell-scripting alongside a few other tricks.

Create incremental snapshots of individual folders using find and tar-gzip
Creates an incremental snapshot of individual folders.

Record microphone input and output to date stamped mp3 file
record audio notes or meetings requires arecord and lame run mp3gain on the resulting file to increase the volume / quality ctrl-c to stop recording

download all the presentations from UTOSC2010
miss a class at UTOSC2010? need a refresher? use this to curl down all the presentations from the UTOSC website. (http://2010.utosc.com) NOTE/WARNING this will dump them in the current directory and there are around 37 and some are big - tested on OSX10.6.1

list file descriptors opened by a process
Useful for examining hostile processes (backdoors,proxies)


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