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Watches for file modifications in the current directory and tails the file.
I know how hard it is to find an old command running through all the files because you couldn't remember for your life what it was. Heres the solution!! Grep the history for it. depending on how old the command you can head or tail or if you wanted to search all because you cannot think how long ago it was then miss out the middle part of the command. This is a very easy and effective way to find that command you are looking for.
zsh: list of files sorted by size, greater than 100mb, head the top 5. '**/*' is recursive, and the glob qualifiers provide '.' = regular file, 'L' size, which is followed by 'm' = 'megabyte', and finally '+100' = a value of 100
This one is tried and tested for Ubuntu 12.04. Works great for tailing any file over http.
Simply add this to whatever apache startup script you have, or if you are on a MAC, create a new automator application. This will show a pretty growl notification whenever theres a new Apache error log entry. Useful for local development
end_w_nl filename
will check if the last byte of filename is a unix newline character. tail -c1 yields the file's last byte and xxd converts it to hex format.
logtop show number of lines per second, also classify them so you can show a "top" of every aspect of your logfile :
tail -f access.log | awk '{print $1; fflush();}' | logtop
Realtime lines per second in a log file using python ... identical to perl version, except python is much better :)
This is a little trickier than finding the last Sunday, because you know the last Sunday is in the first position of the last line. The trick is to use the NF less than or equal to 7 so it picks up all the lines then grep out any empty lines.
tail() { thbin="/usr/bin/tail"; if [ "${1:0:1}" != "-" ]; then fc=$(($#==0?1:$#)); lpf="$((($LINES - 3 - 2 * $fc) / $fc))"; lpf="$(($lpf<1?2:$lpf))"; [ $fc -eq 1 ] && $thbin -n $lpf "$@" | /usr/bin/fold -w $COLUMNS | $thbin -n $lpf || $thbin -n $lpf "$@"; else $thbin "$@"; fi; unset lpf fc thbin; }
This is a function that implements an improved version of tail. It tries to limit the number of lines so that the screen is filled completely. It works with pipes, single and multiple files. If you add different options to tail, they will overwrite the settings from the function.
It doesn't work very well when too many files (with wrapped lines) are specified.
Its optimised for my three-line prompt.
It also works for head. Just s/tail/head/g
Don't set 'thbin="tail"', this might lead to a forkbomb.
Run the alias command, then issue
ps aux | tail
and resize your terminal window (putty/console/hyperterm/xterm/etc) then issue the same command and you'll understand.
${LINES:-`tput lines 2>/dev/null||echo -n 12`}
Insructs the shell that if LINES is not set or null to use the output from `tput lines` ( ncurses based terminal access ) to get the number of lines in your terminal. But furthermore, in case that doesn't work either, it will default to using the default of 80.
The default for TAIL is to output the last 10 lines, this alias changes the default to output the last x lines instead, where x is the number of lines currently displayed on your terminal - 7. The -7 is there so that the top line displayed is the command you ran that used TAIL, ie the prompt.
Depending on whether your PS1 and/or PROMPT_COMMAND output more than 1 line (mine is 3) you will want to increase from -2. So with my prompt being the following, I need -7, or - 5 if I only want to display the commandline at the top. ( http://www.askapache.com/linux/bash-power-prompt.html )
275MB/748MB
[7995:7993 - 0:186] 06:26:49 Thu Apr 08 [askapache@n1-backbone5:/dev/pts/0 +1] ~
In most shells the LINES variable is created automatically at login and updated when the terminal is resized (28 linux, 23/20 others for SIGWINCH) to contain the number of vertical lines that can fit in your terminal window. Because the alias doesn't hard-code the current LINES but relys on the $LINES variable, this is a dynamic alias that will always work on a tty device.
This will quickly display files last changed in a directory, with the newest on top.
List all files in a directory in reverse order by modified timestamp. When piped through tail the user will see the most recent file name.
this way you have the multitail with all its options running on your own machine with the tails of the two remote machines inside :)
Tail is much faster than sed, awk because it doesn't check for regular expressions.
say only processes a complete file, at eof, so following a file isn't possible. Quick and dirty perl oneliner to feed each line from the tail -f to say. Yes, expensive to lauch a new process each line.
This little ditty was prompted by a discussion on how horrible it is to use VoiceOver on ncurses programs such as irssi.
Using tail to follow and standard perl to count and print the lps when lines are written to the logfile.
You can actually do the same thing with a combination of head and tail. For example, in a file of four lines, if you just want the middle two lines:
head -n3 sample.txt | tail -n2
Line 1 --\
Line 2 } These three lines are selected by head -n3,
Line 3 --/ this feeds the following filtered list to tail:
Line 4
Line 1
Line 2 \___ These two lines are filtered by tail -n2,
Line 3 / This results in:
Line 2
Line 3
being printed to screen (or wherever you redirect it).
Uses history to get the last n+1 commands (since this command will appear as the most recent), then strips out the line number and this command using sed, and appends the commands to a file.
Yep, now you can finally google from the command line!
Here's a readable version "for your pleasure"(c):
google() { # search the web using google from the commandline
# syntax: google google
query=$(echo "$*" | sed "s:%:%25:g;s:&:%26:g;s:+:%2b:g;s:;:%3b:g;s: :+:g")
data=$(wget -qO - "https://ajax.googleapis.com/ajax/services/search/web?v=1.0&q=$query")
title=$(echo "$data" | tr '}' '\n' | sed "s/.*,\"titleNoFormatting//;s/\":\"//;s/\",.*//;s/\\u0026/'/g;s/\\\//g;s/#39\;//g;s/'amp;/\&/g" | head -1)
url="$(echo "$data" | tr '}' '\n' | sed 's/.*"url":"//;s/".*//' | head -1)"
echo "${title}: ${url} | http://www.google.com/search?q=${query}"
}
Enjoy :)