Commands using tail (292)
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3history | perl -lane '$lsize{$_} = scalar(@F); if($longest<$lsize{$_}) { $longest = $lsize{$_}; print "$_"; };' | tail -n1
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This truncates any lines longer than 80 characters. Also useful for looking at different parts of the line, e.g. cut -b 50-100 shows columns 50 through 100.
3tail -f logfile.log | cut -b 1-80 -
See man vmstat for information about the statistics. This does the same thing without the timestamp:
vmstat 5Show Sample Output3while [ 1 ]; do echo -n "`date +%F_%T`" ; vmstat 1 2 | tail -1 ; sleep 4; done -
This command will show the 20 processes using the most CPU time (hungriest at the bottom). You can see the 20 most memory intensive processes (hungriest at the bottom) by running:
ps aux | sort +3n | tail -20Or, run both:echo "CPU:" && ps aux | sort +2n | tail -20 && echo "Memory:" && ps aux | sort +3n | tail -203ps aux | sort +2n | tail -20 -
yes 6 (tail from 6th line)
3ls -t | tail +6 | xargs rm -
Figures out what has changed in the last 12 hours. Change the author to yourself, change the time since to whatever you want. Show Sample Output
3git diff --stat `git log --author="XXXXX" --since="12 hours ago" --pretty=oneline | tail -n1 | cut -c1-40` HEAD -
Prints the top 10 memory consuming processes (with children and instances aggregated) sorted by total RSS and calculates the percentage of total RAM each uses. Please note that since RSS can include shared libraries it is possible for the percentages to add up to more that the total amount of RAM, but this still gives you a pretty good idea. Also note that this does not work with the mawk version of awk, but it works fine with GNU Awk which is on most Linux systems. It also does not work on OS X. Show Sample Output
3TR=`free|grep Mem:|awk '{print $2}'`;ps axo rss,comm,pid|awk -v tr=$TR '{proc_list[$2]+=$1;} END {for (proc in proc_list) {proc_pct=(proc_list[proc]/tr)*100; printf("%d\t%-16s\t%0.2f%\n",proc_list[proc],proc,proc_pct);}}'|sort -n |tail -n 10 -
Several people have submitted commands to do this, but I think this is the simplest solution. It also happens to be the most portable one: It should work with any sh or csh derived shell under any UNIX-like OS. Oh by the way, with my German locale ($LC_TIME set appropriately) it prints "g" most of the time, and sometimes (on Wednesdays) it prints "h". It never prints "y". Show Sample Output
3date +%A | tail -2c -
3tail -f file |xargs -IX printf "$(date -u)\t%s\n" X
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3history | awk '{print $2}' | awk 'BEGIN {FS="|"}{print $1}' | sort | uniq -c | sort -n | tail | sort -nr
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3find /var/log -iregex '.*[^\.][^0-9]+$' -not -iregex '.*gz$' 2> /dev/null | xargs tail -n0 -f | ccze -A
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3tail -f /var/log/squid/access.log | perl -p -e 's/^([0-9]*)/"[".localtime($1)."]"/e'
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script -f /tmp/foo will place all output of the terminal, including carriage returns, to a file. This file can be tail dash-eff'ed by one or more other terminals to display the information of the main terminal. Good way to share one's screen on short notice. Note: This produces a very accurate output, but that includes depending on the size of your terminal to be the same. You can clear screens or even resize the terminal for others using this function; I use it in conjunction with the "mid" command in my list. Show Sample Output
3script -f /tmp/foo; tail -f /tmp/foo -
Output lines starting at line 2.
3tail -n +2 foo.txt -
The router Technicolor TC7200 has an exploit where the file http://192.168.0.1/goform/system/GatewaySettings.bin is open for unauthenticated access. Even though it is binary, the 2 last strings are the username and password for the pages for router management. It can be read using the 'strings' command, 'hexdump -C' or a hexadecimal editor. (default user/password = admin/admin) Reveals more configuration, including SSID name and Key for the wifi network:
wget -q -O - http://192.168.0.1/goform/system/GatewaySettings.binHexadecimal dump of the file:wget -q -O - http://192.168.0.1/goform/system/GatewaySettings.bin | hexdump -CShow Sample Output3wget -q -O - http://192.168.0.1/goform/system/GatewaySettings.bin | strings | tail -n 2 -
This is a standard procedure for me, whenever I set up a new Raspberry Pi system. Because the default user is "pi", I quickly replace it with my own (e.g. "kostis"), but I have to substitute that user to all of pi's groups first, before deleting the default account. xargs helps a lot with that in a single line, while avoiding boring "for" loops. For everything trickier, there's always "parallel" :)
3groups pi | xargs -n 1 | tail -n +4 | xargs -n 1 sudo adduser kostis -
Tuned for short command line - you can set the path to sessionstore.js more reliable instead of use asterixes etc. Usable when you are not at home and really need to get your actual opened tabs on your home computer (via SSH). I am using it from my work if I forgot to bookmark some new interesting webpage, which I have visited at home. Also other way to list tabs when your firefox has crashed (restoring of tabs doesn't work always). This script includes also tabs which has been closed short time before.
2F="$HOME/.moz*/fire*/*/session*.js" ; grep -Go 'entries:\[[^]]*' $F | cut -d[ -f2 | while read A ; do echo $A | sed s/url:/\n/g | tail -1 | cut -d\" -f2; done -
2mysql -u<user> -p<password> -s -e 'DESCRIBE <table>' <database> | tail -n +1 | awk '{ printf($1",")}' | head -c -1
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get diskusage of files (in this case logfiles in /var/log) modified during the last n days:
sudo find /var/log/ -mtime -n -type f | xargs du -chn -> last modified n*24 hours ago Numeric arguments can be specified as +n for greater than n, -n for less than n, n for exactly n. => so 7*24 hours (about 7 days) is -7sudo find /var/log/ -mtime -7 -type f | xargs du -ch | tail -n1Show Sample Output2sudo find /var/log/ -mtime -7 -type f | xargs du -ch | tail -n1 -
2find /path/to/dir -type f -printf "%T@|%p\n" 2>/dev/null | sort -n | tail -n 1| awk -F\| '{print $2}'
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Finds all C++, Python, SWIG files in your present directory (uses "*" rather than "." to exclude invisibles) and counts how many lines are in them. Returns only the last line (the total). Show Sample Output
2find * \( -name "*.[hc]pp" -or -name "*.py" -or -name "*.i" \) -print0 | xargs -0 wc -l | tail -n 1 -
Just a quick hack to give reasonable filenames to TrueType and OpenType fonts. I'd accumulated a big bunch of bizarrely and inconsistently named font files in my ~/.fonts directory. I wanted to copy some, but not all, of them over to my new machine, but I had no idea what many of them were. This script renames .ttf files based on the name embedded inside the font. It will also work for .otf files, but make sure you change the mv part so it gives them the proper extension. REQUIREMENTS: Bash (for extended pattern globbing), showttf (Debian has it in the fontforge-extras package), GNU grep (for context), and rev (because it's hilarious). BUGS: Well, like I said, this is a quick hack. It grew piece by piece on the command line. I only needed to do this once and spent hardly any time on it, so it's a bit goofy. For example, I find 'rev | cut -f1 | rev' pleasantly amusing --- it seems so clearly wrong, and yet it works to print the last argument. I think flexibility in expressiveness like this is part of the beauty of Unix shell scripting. One-off tasks can be be written quickly, built-up as a person is "thinking aloud" at the command line. That's why Unix is such a huge boost to productivity: it allows each person to think their own way instead of enforcing some "right way". On a tangent: One of the things I wish commandlinefu would show is the command line HISTORY of the person as they developed the script. I think it's that conversation between programmer and computer, as the pipeline is built piece-by-piece, that is the more valuable lesson than any canned script. Show Sample Output
2shopt -s extglob; for f in *.ttf *.TTF; do g=$(showttf "$f" 2>/dev/null | grep -A1 "language=0.*FullName" | tail -1 | rev | cut -f1 | rev); g=${g##+( )}; mv -i "$f" "$g".ttf; done -
'data' is the directory to backup, 'backup' is directory to store snapshots. Backup files on a regular basis using hard links. Very efficient, quick. Backup data is directly available. Same as explained here : http://blog.interlinked.org/tutorials/rsync_time_machine.html in one line. Using du to check the size of your backups, the first backup counts for all the space, and other backups only files that have changed. Show Sample Output
2rsync -av --link-dest=$(ls -1d /backup/*/ | tail -1) /data/ /backup/$(date +%Y%m%d%H%M)/ -
You can use this one-liner for a quick and dirty (more customizable) alternative to the watch command. The keys to making this work: everything exists in an infinite loop; the loop starts with a clear; the loop ends with a sleep. Enter whatever you'd like to keep an eye on in the middle. Show Sample Output
2while (true); do clear; uname -n; echo ""; df -h /; echo ""; tail -5 /var/log/auth.log; echo ""; vmstat 1 5; sleep 15; done -
Returns a the directory depth.
2find . -printf '%d\n' | sort -n | tail -1 - < 1 2 3 4 5 > Last ›
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