Commands tagged regex (55)

  • seed the random number generator, find all matches in a file put all matches from the capture group into an array return a random element from the array Show Sample Output


    0
    awk 'BEGIN{srand()} match($0, /DELTA=([0-9]+);/, a) {w[i++]=a[1]} END {print w[int(rand()*i)]}' file.name
    jkirchartz · 2015-11-13 17:56:34 0
  • I personally like it very much and have wrapped it into a function, named "apt-propos" ;), also you can use --names-only option for a sort-of "apt-whatis"


    0
    apt-cache search byo | sed "s/^\([[:alnum:]\.-]*\) - /\1=%%%=- /" | column -s '=%%%=' -t
    VoidDroid · 2015-10-18 10:55:34 0
  • An advantage is that this doesn't modify remained string at all. One can change {0,1} with {0,n} to drop several columns


    1
    perl -pE's/(\S+\s*){0,1}//'
    pung96 · 2015-05-09 15:14:58 0
  • Command returns valid IP addresses. Append the following regex to additionally filter out NAT and reserved IP addresses | grep -Ev "^0|\.0[0-9]|^10\.|^127\.|^169\.|^172\.(1[6-9]|2[0-9]|3[01])|^192.168.|^2(2[4-9]|3[0-9])|^2(4[0-9]|5[0-5])"


    0
    grep -Eoa "\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b" Filetosearch.txt
    jsbrown · 2014-11-02 19:50:54 0

  • 0
    finger $(whoami) | perl -ne '/Name: ([a-zA-Z0-9 ]{1,})/ && print "$1\n"'
    zil0g · 2014-09-30 11:37:47 0
  • Its possible to user a simple regex to extract de username from the finger command. The final echo its optional, just for remove the initial space Show Sample Output


    0
    finger $(whoami) | egrep -o 'Name: [a-zA-Z0-9 ]{1,}' | cut -d ':' -f 2 | xargs echo
    swebber · 2014-09-24 01:22:07 1
  • Thx Mass1 for the sharing


    0
    ifconfig | egrep -A2 "eth|wlan" | tr -d "\n"| sed 's/\-\-/\n/g'|awk '{print "mac: "$5 " " $7}' | sed 's/addr:/addr: /g'
    Koobiac · 2014-09-11 08:18:18 1
  • Print the IP address and the Mac address in the same line Show Sample Output


    1
    ifconfig | head -n 2 | tr -d '\n' | sed -n 's/.*\(00:[^ ]*\).*\(adr:[^ ]*\).*/mac:\1 - \2/p'
    Koobiac · 2014-09-03 14:35:27 7
  • Usage: command | hl 'regex'


    0
    hl() { while read -r; do printf '%s\n' "$(perl -p -e 's/('"$1"')/\a\e[7m$1\e[0m/g' <<< "$REPLY")"; done; }
    nyuszika7h · 2014-08-05 22:29:08 0

  • 1
    find * -regextype posix-extended -regex '.*\.(ext_1|ext_2)' -exec cp {} copy_target_directory \;
    shawn_abdushakur · 2014-02-06 15:58:32 0
  • Will find and list all core files from the current directory on. You can pass | xargs rm -i to be prompted for the removal if you'd like to double check before removal.


    0
    find . -type f -regex ".*/core.[0-9][0-9][0-9][0-9]$"
    H3liUS · 2014-01-17 16:44:47 0
  • set BLOCK to "title" or any other HTML / RSS / XML tag and curl URL to get everything in-between e.g. some text


    0
    curl ${URL} 2>/dev/null|grep "<${BLOCK}>"|sed -e "s/.*\<${BLOCK}\>\(.*\)\<\/${BLOCK}\>.*/\1/g"
    c3w · 2013-08-31 14:53:54 0
  • This is a slightly modified version of http://www.commandlinefu.com/commands/view/4283/recursive-search-and-replace-old-with-new-string-inside-files (which did not work due to incorrect syntax) with the added option to sed inside only files named filename.ext


    1
    find . -type f -name filename.exe -exec sed -i "s/oldstring/oldstring/g" {} +;
    eddieb · 2013-05-20 19:17:10 0
  • grep '^[^#]' sample.conf \__/ |||| \_________/ | |||| | | |||| \- Filename | |||| | |||\- Only character in group is '#' | ||| | ||\- Negate character group (will match any cahracter *not* in the | || group) | || | |\- Start new character group (will match any character in the | | group) | | | \- Match beginning of line | \- Run grep Empty lines will also be not matched, because there has to be at least one non-hash-sign character in the line. Show Sample Output


    -5
    grep '^[^#]' squid.conf
    Flow · 2013-02-21 18:51:06 4

  • 0
    diff -BI '^#' file{1,2}
    zlemini · 2013-02-17 11:53:41 0
  • Runs a diff on two files ignore comments and blank lines (diff -I=RE does not work as expected). Adapted from a post found on stackexchange.


    0
    diff -u <(grep -vE '^(#|$)' file1) <(grep -vE '^(#|$)' file2)
    taintedkernel · 2013-02-12 13:59:39 1
  • Reciprocally, we could get the node name from a give Tor IP address => ip2node() { curl -s -d "QueryIP=$1" http://torstatus.blutmagie.de/tor_exit_query.php | grep -oP "Server name:.*'>\K\w+" ; } ip2node 204.8.156.142 BostonUCompSci Show Sample Output


    0
    curl -s -d "CSField=Name" -d "CSInput=BostonUCompSci" http://torstatus.blutmagie.de/index.php | grep -oP "ip=\K(\d+)(\.\d+){3}"
    JisSey · 2012-03-09 16:52:27 0
  • 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 0
  • Sometimes, especially when parsing HTML, you want "all text between two tags, that doesn't contain another tag". For example, to grab only the contents of the innermost <div>s, something like: /<div\b[^>]*>((?:(?!<div).)*)</div>/ ...may be your best option to capture that text. It's not always needed, but is a powerful arrow in your regex quiver in those cases when you do need it. Note that, in general, regular expressions are the Wrong Choice for parsing HTML, anyway. Better approaches are solutions which let you navigate the HTML as a proper DOM. But sometimes, you just need to use the tools available to you. If you don't, then you have two problems.


    0
    Opening_tag((?:(?!Unwanted_tag).)*)Closing_tag
    DewiMorgan · 2012-02-28 02:54:57 0
  • With thanks to dew on Efnet's #regex, back in 2005. This version indents subsequent lines after the first by one space, to make paragraphs visibly obvious -- remove the \3 to prevent this behavior. Lines are only broken at spaces: long strings with no spaces will not wrap, so URLs are safe. Replace the "75"s to make the regex linewrap to other amounts. From the unix commandline, "fold" is likely your better choice, but this snippet is handy in editors which allow regular expressions, in scripting, and other such situations where "fold" is unavailable. Show Sample Output


    0
    s/(?=.{75,})(?:(.{0,75})(?:\r\n?|\n\r?)|(.{0,75}))[ ]/\1\2\n /g
    DewiMorgan · 2012-02-28 02:27:20 0
  • Removes special characters (colors) in '^]]Xm' and '^]]X;Ym' format from file. Use pipe ('input | perl [...]') or stream ('perl [...] You can use 'cat -v infile' as 'input' to show special characters instead of interpreting (there is problem with non-ASCII chars, they are replaced by M-[char]).


    -1
    perl -ne 's/\^.{1,7}?m//g;print'
    Tracerneo · 2012-01-02 01:32:33 0

  • 0
    yum remove \*.i\?86
    niek · 2011-10-27 13:56:24 0
  • Uses sed with a regex to move the linenumbers to the line end. The plain regex (w/o escapes) looks like that: ^([^:]*):(.*) Show Sample Output


    0
    grep -n log4j MainPm.java | sed -e 's/^\([^:]*\):\(.*\)/\2 \1/'
    bash_vi · 2011-10-21 12:50:30 0
  • # Search for an available package on Debian systems using a regex so it only matches packages starting with 'tin'.


    0
    aptitude search ^tin
    defiantredpill · 2011-10-20 17:51:36 0
  • This command is useful when you are programming, for example.


    -1
    sed -i 's/[ \t]\+$//g' file.txt
    elder · 2011-09-07 01:47:44 0
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Converts uppercase chars in a string to lowercase
Another alternative is to define a function: lower() { echo ${@,,} } lower StrinG

auto terminal title change
above line in .bash_profile will give you window title in putty or terminal client when you login to your remote server

Run a command, store the output in a pastebin on the internet and place the URL on the xclipboard
The URL can then be pasted with a middle click. This is probably useful when trying to explain problems over instant messaging when you don't have some sort of shared desktop.

Pipe the result of a command to IRC (channel or query)
$ command | my_irc Pipe whatever you want to this function, it will, if everything goes well, be redirected to a channel or a user on an IRC server. Please note that : - I am not responsible of flood excesses you might provoke. - that function does not reply to PINGs from the server. That's the reason why I first write in a temporary file. Indeed, I don't want to wait for inputs while being connected to the server. However, according to the configuration of the server and the length of your file, you may timeout before finishing. - Concerning the server, the variable content must be on the form "irc.server.org 6667" (or any other port). If you want to make some tests, you can also create a fake IRC server on "localhost 55555" by using $ netcat -l -p 55555 - Concerning the target, you can choose a channel (beginning with a '#' like "#chan") or a user (like "user") - The other variables have obvious names.

Remove security limitations from PDF documents using ghostscript
Remove security from PDF document using this very simple command on Linux and OSX. You need ghostscript for this baby to work.

Search and play youtube videos directly to terminal (no X needed)
Same as other command, however uses youtube-dl internal search (thanks to qoxxxx mentioning this) It does however seem to be a little buggy and youtube-dl crashes sometimes. ## pyt 'Stairway to heaven - Led Zeppelin' pyt 'brain damage - Pink Floyd' No web browser or even X needed. Just a cli and internet connection! mplayer is pauseable and can skip ahead This may break if youtube changes their search html.

create tar archive of files in a directory and its sub-directories
creates a compressed tar archive of files in /path/foo and writes to a timestamped filename in /path.

add the result of a command into vi
':r!ls -l' results in listing the files in the current directory and paste it into vi

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"

Convert .wma files to .ogg with ffmpeg


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