Commands using grep (1,935)
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Works in Ubuntu, I hope it will work on all Linux machines. For Unixes, tail should be capable of handling more than one file with '-f' option. This command line simply take log files which are text files, and not ending with a number, and it will continuously monitor those files. Putting one alias in .profile will be more useful.
6find /var/log -type f -exec file {} \; | grep 'text' | cut -d' ' -f1 | sed -e's/:$//g' | grep -v '[0-9]$' | xargs tail -f -
Using the grep command, retrieve all lines from any log files in /var/log/ that have one of the problem states
6grep -2 -iIr "err\|warn\|fail\|crit" /var/log/* -
Check which files are opened by Firefox then sort by largest size (in MB). You can see all files opened by just replacing grep to "/". Useful if you'd like to debug and check which extensions or files are taking too much memory resources in Firefox. Show Sample Output
6FFPID=$(pidof firefox-bin) && lsof -p $FFPID | awk '{ if($7>0) print ($7/1024/1024)" MB -- "$9; }' | grep ".mozilla" | sort -rn -
All valid files are withheld so only failures show up. No output, all checks good.
6md5sum --check MD5SUMS | grep -v ": OK" -
I took matthewbauer's cool one-liner and rewrote it as a shell function that returns all the suggestions or outputs "OK" if it doesn't find anything wrong. It should work on ksh, zsh, and bash. Users that don't have tee can leave that part off like this:
spellcheck(){ typeset y=$@;curl -sd "<spellrequest><text>$y</text></spellrequest>" https://google.com/tbproxy/spell|sed -n '/s="[1-9]"/{s/<[^>]*>/ /g;s/\t/ /g;s/ *\(.*\)/Suggestions: \1\n/g;p}';}Show Sample Output6spellcheck(){ typeset y=$@;curl -sd "<spellrequest><text>$y</text></spellrequest>" https://www.google.com/tbproxy/spell|sed -n '/s="[0-9]"/{s/<[^>]*>/ /g;s/\t/ /g;s/ *\(.*\)/Suggestions: \1\n/g;p}'|tee >(grep -Eq '.*'||echo -e "OK");} -
6svn log -r {`date "+%Y-%m-%d"`}:HEAD|grep '^r[0-9]' |cut -d\| -f2|sort|uniq -c
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Change the name of the process and what is echoed to suit your needs. The brackets around the h in the grep statement cause grep to skip over "grep httpd", it is the equivalent of grep -v grep although more elegant. Show Sample Output
6TOTAL_RAM=`free | head -n 2 | tail -n 1 | awk '{ print $2 }'`; PROC_RSS=`ps axo rss,comm | grep [h]ttpd | awk '{ TOTAL += $1 } END { print TOTAL }'`; PROC_PCT=`echo "scale=4; ( $PROC_RSS/$TOTAL_RAM ) * 100" | bc`; echo "RAM Used by HTTP: $PROC_PCT%" -
Saves to a PDF with title and alt text of comic. As asked for on http://bbs.archlinux.org/viewtopic.php?id=91100 Change xkcd.com to dynamic.xkcd.com/comics/random for a random comic.
6curl -sL xkcd.com | grep '<img [^>]*/><br/>' | sed -r 's|<img src="(.*)" title="(.*)" alt="(.*)" /><br/>|\1\t\2\t\3|' > /tmp/a; curl -s $(cat /tmp/a | cut -f1) | convert - -gravity south -draw "text 0,0 \"$(cat /tmp/a | cut -f2)\"" pdf:- > xkcd.pdf -
Uses lsof to display the full path of ".log" files opened by a specified PID.
6lsof -p 1234 | grep -E "\.log$" | awk '{print $NF}' -
6ffmpeg -f x11grab -s `xdpyinfo | grep 'dimensions:'|awk '{print $2}'` -r 25 -i :0.0 -sameq /tmp/out.mpg > /root/howto/capture_screen_video_ffmpeg
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6cat list|while read lines;do echo "USER admin">ftp;echo "PASS $lines">>ftp;echo "QUIT">>ftp;nc 192.168.77.128 21 <ftp>ftp2;echo "trying: $lines";cat ftp2|grep "230">/dev/null;[ "$?" -eq "0" ]&& echo "pass: $lines" && break;done
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Plays the mp3 stream of The Current as a background job. When you are done run:
fg %1then to exit Quite possible with Growl for mac I'd guess, although have not tried. Libnotify needed for notification, stream will still work otherwise6mplayer http://minnesota.publicradio.org/tools/play/streams/the_current.pls < /dev/null | grep --line-buffered "StreamTitle='.*S" -o | grep --line-buffered "'.*'" -o > mus & tail -n0 -f mus | while read line; do notify-send "Music Change" "$line";done -
Uses date to grep de logfile for today and uses it to get the last hour logs. Can be used to get last minute logs or today's logs. Show Sample Output
6grep -i "$(date +%b\ %d\ %H)" syslog -
Returns logs between HH:M[Mx-My], for example, between 13:40 and 13:45. Show Sample Output
6grep -i "$(date +%b" "%d )13:4[0-5]" syslog -
emerge,apt-get,yum... all update your system. This will at some point replace either a runtime dependency or a process (which is still running). This oneliner will list what processes need to be restarted Show Sample Output
6deadlib() { lsof | grep 'DEL.*lib' | cut -f 1 -d ' ' | sort -u; } -
faster ;) but your idea is really cool
6ps -ef | grep c\\ommand -
Using NMAP to check to see if port 22(SSH) is open on servers and network devices. Show Sample Output
6nmap -oG - -T4 -p22 -v 192.168.0.254 | grep ssh -
You can choose these mirror servers to get gpg keys, if the official one ever goes offline keyserver.ubuntu.com pool.sks-keyservers.net subkeys.pgp.net pgp.mit.edu keys.nayr.net keys.gnupg.net wwwkeys.en.pgp.net #(replace with your country code fr, en, de,etc)
6sudo apt-get update 2> /tmp/keymissing; for key in $(grep "NO_PUBKEY" /tmp/keymissing |sed "s/.*NO_PUBKEY //"); do echo -e "\nProcessing key: $key"; gpg --keyserver pool.sks-keyservers.net --recv $key && gpg --export --armor $key |sudo apt-key add -; done -
6ifconfig eth0 | grep -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}'
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Displays the same output as "cal", but with the current day highlighted (probably dependent on gnu grep, as I'm not sure other grep's support the "--color=auto" option). Tested and working on Ubuntu 11 and OSX Lion. Show Sample Output
6cal |grep -A7 -B7 --color=auto $(date +%d) -
I used to use the Firefox "View page info" feature a lot to determine how stale the web page I was looking at was. Now that I use mostly Chrome I miss that feature, so here is a command line alternative using wget. The -S says to display the server response, the --spider says to not download any files/pages, just fetch the header. The output goes to stderr, so to grep it you use 2>&1 to combine the stderr stream with stdout, the pipe that to grep for Last-Modified. You can use curl instead if you have it installed, like this:
curl --head -s http://osswin.sourceforge.net | grep ModShow Sample Output6wget -S --spider http://osswin.sourceforge.net/ 2>&1 | grep Mod -
you may want &hl=en for &hl=es for the language you may want imgsz=xxlarge for imgsz=large or whatever filter you may want q=apples or whatever
6for i in {1..10};do wget $(wget -O- -U "" "http://images.google.com/images?imgsz=xxlarge&hl=en&q=wallpaper+HD&start=$(($RANDOM%900+100))" --quiet | grep -oe 'http://[^"]*\.jpg' | head -1);done -
I often have to google this so I put it here for quick reference.
6netstat -np | grep -v ^unix -
useful for discarding even those comments which start with blanks or those empty lines which contain blanks Show Sample Output
6grep -vE '^\s*(#|$)' textfile -
6ls -al --time-style=+%D| grep `date +%D`
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