Commands using perl (369)

  • Search in decimal rather than hex. od dumps the character list, cut to remove offsets, sort -u gives the used characters. seq gives the comparison list, but we need this sorted alphabetically for comm, which does the filtering. I drop to perl to convert back to characters (is there a better way?) and then use od to dump them in a print-safe format. Show Sample Output


    0
    comm -13 <(od -vw1 -tu1 dummy.txt|cut -c9-|sort -u) <(seq 0 127|sort)|perl -pe '$_=chr($_)'|od -c
    bazzargh · 2012-01-09 01:32:20 7

  • 0
    perl -e 'for (<*.mp3>) { $old = $_; s/ /-/g; rename $old, $_ }'
    ironcamel · 2012-02-16 15:53:41 3
  • Commandline perl filter for, using a production.log from a rails app, display on realtime the count of requests grouped by "seconds to complete" (gross round, but fair enough for an oneliner) :) Show Sample Output


    0
    tail -f production.log | perl -ne 'if (/^Completed.in.(\d+)/){$d = int($1/1000);print "\n";$f{$d}++;for $t (sort(keys(%f))){print $t."s: ".$f{$t}."\n"}}'
    theist · 2012-02-23 14:37:33 3
  • handels @, ?, whitespaces in names. replace "?" and "add" by "!" and "rm" for svn mass remove. ---> I m looking for a nicer way to write it, perhaps with something using " perl -ne '`blahblah` if /\?(.*)/' " Show Sample Output


    0
    svn st | awk ' {if ( $1 == "?" ){print $1="",$0}} ' | sed -e 's/^[ \t]*//' | sed 's/ /\\ /g' | perl -ne '`svn add ${1}@` if /(.*)(@*)(.*)/'
    JulieCaroline · 2012-02-23 18:42:02 3
  • People are *going* to post the wrong ways to do this. It's one of the most common form-validation tasks, and also one of the most commonly messed up. Using a third party tool or library like exim means that you are future-proofing yourself against changes to the email standard, and protecting yourself against the fact that actually checking whether an email address is valid is *not possible*. Still, perhaps your boss is insisting you really do need to check them internally. OK. Read the RFCs. The bet before the @ is specified by RFC2821 and RFC2822. The domain name part is specified by RFC1035, RFC1101, RFC1123 and RFC2181. Generally, when people say "email address", they mean that part of the address that the RFC terms the "addr-spec": the "blah@domain.tld" address, with no display names, comments, quotes, etc. Also "root@localhost" and "root" should be invalid, as should arbitrary addressing schemes specified by a protocol indicator, like "jimbo@myprotocol:foo^bar^baz". So... With the smallest poetic license for readability (allowing underscores in domain names so we can use "\w" instead of "[a-z0-9]"), the RFCs give us: ^(?:"(?:[^"\\]|\\.)+"|[-^!#\$%&'*+\/=?`{|}~.\w]+)@(?=.{3,255}$)(?:[\w][\w-]{0,62}\.){1,128}[\w][\w-]{0,62}$ Not perfect, but the best I can come up with, and most compliant I've found. I'd be interested to see other people's ideas, though. It's still not going to verify you an address fersure, properly, 100% guaranteed legit, though. What else can you do? Well, you could also: * verify that the address is either a correct dotted-decimal IP, or contains letters. * remove reserved domains (.localhost, .example, .test, .invalid), reserved IP ranges, and so forth from the address. * check for banned domains (whitehouse.gov, example.com...) * check for known TLDs including alt tlds. * see if the domain has an MX record set up: if so, connect to that host, else connect to the domain. * see if the given address is accepted by the server as a recipient or sender (this fails for yahoo.*, which blocks after a few attempts, assuming you are a spammer, and for other domains like rediffmail.com, home.com). But these are moving well out of the realm of generic regex checks and into the realm of application-specific stuff that should be done in code instead - especially the latter two. Hopefully, this is all you needed to point out to your boss "hey, email validation this is a dark pit with no bottom, we really just want to do a basic check, then send them an email with a link in it: it's the industry standard solution." Of course, if you want to go nuts, here's an idea that you could do. Wouldn't like to do it myself, though: I'd rather just trust them until their mail bounces too many times. But if you want it, this (untested) code checks to see if the mail domain works. It's based on a script by John Coggeshall and Jesse Houwing that also asked the server if the specific email address existed, but I disliked that idea for several reasons. I suspect: it will get you blocked as a spambot address harvester pretty quick; a lot of servers would lie to you; it would take too much time; this way you can cache domains marked as "OK"; and I suspect it would add little to the reliability test. // Based on work by: John Coggeshall and Jesse Houwing. // http://www.zend.com/zend/spotlight/ev12apr.php mailRegex = '^(?:"(?:[^"\\\\]|\\\\.)+"|[-^!#\$%&\'*+\/=?`{|}~.\w]+)'; mailRegex .= '@(?=.{3,255}$)(?:[\w][\w-]{0,62}\.){1,128}[\w][\w-]{0,62}$'; function ValidateMail($address) {   global $mailRegex; // Yes, globals are evil. Put it inline if you want.   if (!preg_match($mailRegex)) {     return false;   }   list ( $localPart, $Domain ) = split ("@",$Email);   // connect to the first available MX record, or to domain if no MX record.   $ConnectAddress = new Array();   if (getmxrr($Domain, $MXHost)) {     $ConnectAddress = $MXHost;   } else {     $ConnectAddress[0] = $Domain;   }   // check all MX records in case main server is down - may take time!   for ($i=0; $i < count($ConnectAddress); $i++ ) {     $Connect = fsockopen ( $ConnectAddress[$i], 25 );     if ($Connect){       break;     }   }   if ($Connect) {     socket_set_blocking($Connect,0);     // Only works if socket_blocking is off.     if (ereg("^220", $Out = fgets($Connect, 1024))) {       fclose($Connect); // Unneeded, but let's help the gc.       return true;     }     fclose($Connect); // Help the gc.   }   return false; } Show Sample Output


    0
    perl -e "print 'yes' if `exim -bt $s_email_here | grep -c malformed`;"
    DewiMorgan · 2012-02-28 04:42:41 3
  • loop through files in .php extension make a .bak of each of them find the base64_decode function and remove it


    0
    for f in `find . -name "*.php"`; do perl -p -i.bak -e 's/<\?php \/\*\*\/ eval\(base64_decode\(\"[^\"]+"\)\);\?>//' $f; done
    lizuka · 2012-03-12 10:44:33 3
  • Provides a much cleaner, easier to read output than the closest alternative, ls -1R. This alternative makes it easier to differentiate directories from files: find . -printf '%y %p\n' | perl -ne 'if( m/(\w) (.*)\/(.*)/ ) { $t = $1; $p = $2; $f = $3; $t =~ s/[^d]/ /; $p =~ s/[^\/]/ /g; $p =~ s/\//|/g; print "$t $p/$f\n"; } elsif( m/(\w) (.*)/ ) { print "$1 $2\n"; } else { print "error interpreting: \"$_\"\n"; }' Show Sample Output


    0
    find . -printf '%p\n' | perl -ne 'if( m/(.*)\/(.*)/ ) { $p = $1; $f = $2; $p =~ s/[^\/]/ /g; $p =~ s/\//|/g; print "$p/$f\n"; } elsif( m/(.*)/ ) { print "$1\n"; } else { print "error interpreting: \"$_\"\n"; }'
    cbetti · 2012-04-24 19:51:00 3
  • This also works with -i, just like one might do with sed.


    0
    perl -p -e 's/\\n/\n/g'
    icorbett · 2012-06-06 15:37:34 4

  • 0
    cat ~/.bash_history | perl -lane 'if($F[0] eq "sudo"){$hash{$F[1]}++}else{$hash{$F[0]}++};$all++;END {@top = map {[$_, $hash{$_}]} sort {$hash{$b}<=>$hash{$a}} keys %hash;printf("%10s%10d%10.2f%%\n", $_->[0],$_->[1],$_->[1]/$all*100) for @top[0..9]}'
    vinian · 2012-07-02 09:38:06 7

  • 0
    perl -e '$s="$s\xFF" while length($s)<512; print $s while 1' | dd of=/dev/sdX
    stonefoz · 2012-08-20 05:33:28 4
  • works where perl works, because the awk version is gnu awk only. Show Sample Output


    0
    cat log | perl -ne 'use POSIX; s/([\d.]+)/strftime "%y-%m-%d %H:%M:%S", localtime $1/e,print if /./'
    bs · 2012-09-19 06:38:31 4
  • Encode HTML entities supporting UTF-8 input and output


    0
    perl -MHTML::Entities -ne 'print encode_entities($_)' /tmp/subor.txt
    brx75x · 2012-10-11 08:31:14 28

  • 0
    # strace ... | perl -lne '@F=split(/\\/, $_);for(@F){push @ddd, sprintf("%x", oct("0" . $_))}END{shift @ddd; print pack("H*", join("", @ddd));}'
    zwxajh · 2012-10-16 14:24:13 4

  • 0
    perl -pi -e 's/:([\w\d_]+)(\s*)=>/\1:/g' **/*.rb
    asux · 2012-10-16 16:54:40 4

  • 0
    history | perl -pe "~s/ *[0-9]+ *//"
    tomrag · 2012-10-23 22:14:00 5
  • This fixes the extra lines you get when you request only 1 paragraph using a little bit of grep. Just set p to the number of paragraphs you want. Show Sample Output


    0
    p=1 ; lynx -source http://www.lipsum.com/feed/xml?amount=${p} | grep '<lipsum>' -A$(((p-1))) | perl -p -i -e 's/\n/\n\n/g' | sed -n '/<lipsum>/,/<\/lipsum>/p' | sed -e 's/<[^>]*>//g'
    nublaii · 2012-10-24 14:11:52 4
  • find . = will set up your recursive search. You can narrow your search to certain file by adding -name "*.ext" or limit buy using the same but add prune like -name "*.ext" -prune xargs =sets it up like a command line for each file find finds and will invoke the next command which is perl. perl = invoke perl -p sets up a while loop -i in place and the .bak will create a backup file like filename.ext.bak -e execute the following.... 's/ / /;' your basic substitute and replace.


    0
    find . | xargs perl -p -i.bak -e 's/oldString/newString/;'
    RedFox · 2012-11-28 17:11:18 4
  • Since none of the systems I work on have readlink, this works cross-platform (everywhere has perl, right?). Note: This will resolve links. Show Sample Output


    0
    FULLPATH=$(perl -e "use Cwd 'abs_path';print abs_path('$0');")
    follier · 2013-02-01 20:09:34 5
  • When you need a quick ref guide while troubleshooting Apache|NGINX error|access logs. Show Sample Output


    0
    curl http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html 2>/dev/null | grep '^<h3' | grep -v '^\d' | perl -pe 's/^.*(?<=(\d\d\d)) (.*)<\/h3>$/$1 : $2/' | grep -v h3
    klg · 2013-03-06 01:49:08 10
  • The original command doesn't work for me - does something weird with sed (-r) and xargs (-i) with underscores all over... This one works in OSX Lion. I haven't tested it anywhere else, but if you have bash, gpg and perl, it should work. Show Sample Output


    0
    for i in `gpg --list-sigs | perl -ne 'if(/User ID not found/){s/^.+([a-fA-F0-9]{8}).*/\1/; print}' | sort | uniq`; do gpg --keyserver-options no-auto-key-retrieve --recv-keys $i; done
    hank · 2013-03-10 09:15:15 5
  • `pwd` returns the current path `grep -o` prints each slash on new line perl generates the paths sequence: './.', './../.', ... `readlink` canonicalizes paths (it makes the things more transparent) `xargs -tn1` applies chmod for each of them. Each command applied is getting printed to STDERR. Show Sample Output


    0
    pwd|grep -o '/'|perl -ne '$x.="./.";print`readlink -f $x`'|xargs -tn1 chmod 755
    luke_skywalker · 2013-03-14 12:03:44 7
  • Sends log lines from murmur's (the mumble server's) logfile to syslog.


    0
    nohup tail /var/log/murmur.log | perl -ne '/^<.>[0-9:. -]{24}(\d+ => )?(.*)/; $pid=`pgrep -u murmur murmurd | head`; chomp $pid; `logger -p info -t "murmurd[$pid]" \\"$2\\"`;' &
    MagisterQuis · 2013-05-25 01:12:52 6

  • 0
    perl -e 'printf "%o\n", (stat shift)[2]&07777' file
    smallduck · 2013-06-15 19:26:23 6
  • xmas lights for your terminal - switching the $l value to something like 1200 and zooming out on your terminal gives a great view ... Show Sample Output


    0
    perl -le '$l=80;$l2="!" x $l;substr+($l2^=$l2),$l/2,1,"\xFF";{local $_=$l2;y/\0\xFF/ ^/;print;($lf,$rt)=map{substr $l2 x 2,$_%$l,$l;}1,-1;$l2=$lf^$rt;select undef,undef,undef,.1;redo}'
    l3v3l · 2013-06-21 06:00:24 7

  • 0
    perl -lne 'print unless $seen{$_}++'
    kotokz · 2013-07-01 03:47:48 7
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show all established tcp connections on os x

List all files in current dir and subdirs sorted by size
or $ tree -ifsF --noreport .|sort -n -k2|grep -v '/$' (rows presenting directory names become hidden)

Recover tmp flash videos (deleted immediately by the browser plugin)
Newer versions of the flashplayer browser plugin delete the tmp flash video immediately after opening a filehandle to prevent the user from "exporting" the video by simply copying the /tmp/FlashXYZ file. This command searches such deleted flash videos and creates symbolic links to the opened filehandle with the same name as the deleted file. This allows you to play your flash-videos (from e.g. youtube) with e.g. mplayer or copy the buffered video if you want to keep it.

Find where a kind of file is stored
In this case searches for where .desktop files are stored. The resulted is a sorted list of the top directories containing such files.

Split a large file, without wasting disk space
It's common to want to split up large files and the usual method is to use split(1). If you have a 10GiB file, you'll need 10GiB of free space. Then the OS has to read 10GiB and write 10GiB (usually on the same filesystem). This takes AGES. . The command uses a set of loop block devices to create fake chunks, but without making any changes to the file. This means the file splitting is nearly instantaneous. The example creates a 1GiB file, then splits it into 16 x 64MiB chunks (/dev/loop0 .. loop15). . Note: This isn't a drop-in replacement for using split. The results are block devices. tar and zip won't do what you expect when given block devices. . These commands will work: $ hexdump /dev/loop4 . $ gzip -9 < /dev/loop6 > part6.gz . $ cat /dev/loop10 > /media/usb/part10.bin

Random number generation within a range N, here N=10

Find the most recent snapshot for an AWS EBS volume
Uses the python-based AWS CLI (https://aws.amazon.com/cli/) and the JSON query tool, JQ (https://stedolan.github.io/jq/)

FAST Search and Replace for Strings in all Files in Directory
I needed a way to search all files in a web directory that contained a certain string, and replace that string with another string. In the example, I am searching for "askapache" and replacing that string with "htaccess". I wanted this to happen as a cron job, and it was important that this happened as fast as possible while at the same time not hogging the CPU since the machine is a server. So this script uses the nice command to run the sh shell with the command, which makes the whole thing run with priority 19, meaning it won't hog CPU processing. And the -P5 option to the xargs command means it will run 5 separate grep and sed processes simultaneously, so this is much much faster than running a single grep or sed. You may want to do -P0 which is unlimited if you aren't worried about too many processes or if you don't have to deal with process killers in the bg. Also, the -m1 command to grep means stop grepping this file for matches after the first match, which also saves time.

Route outbound SMTP connections through a addtional IP address rather than your primary

GRUB2: set Super Mario as startup tune


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