Commands by cantormath (3)

  • Values will depend on the driver and the hardware specifics, so you need to refer to your driver documentation for proper interpretation of those values. Show Sample Output


    -3
    watch -n 1 cat /proc/net/wireless
    cantormath · 2012-06-07 10:38:21 1
  • Find installed network devices. Show Sample Output


    1
    sudo lshw -C network
    cantormath · 2012-06-07 10:32:49 0
  • Often you want to nmap a list of IPs using the -iL flag. This is an easy way to generate a list of IPs that are online in a specific subnet or IP range (192.168.1.100-110). Show Sample Output


    0
    nmap -sP 192.168.1.0/24 | awk "/^Host/"'{ print $3 }' |nawk -F'[()]' '{print $2}'
    cantormath · 2011-12-31 15:50:22 0

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Alias HEAD for automatic smart output
Run the alias command, then issue $ps aux | head 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 deafault of 12 (-2 = 10). The default for HEAD is to output the first 10 lines, this alias changes the default to output the first x lines instead, where x is the number of lines currently displayed on your terminal - 2. The -2 is there so that the top line displayed is the command you ran that used HEAD, 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-unix/bash-power-prompt.html ) 275MB/748MB [7995:7993 - 0:186] 06:26:49 Thu Apr 08 [[email protected]:/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.

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"

Run a command if today is the last day of the month
This is handy to just shove into a daily cron entry. If you do use cron, make sure to escape the %d with \%d or it will fail.

memcache affinity: queries local memcached for stats, calculates hit/get ratio and prints it out.
queries local memcached for stats, calculates hit/get ratio and prints it out.

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested

format txt as table not joining empty columns
-n switch keeps empty columns If your distribution does not ship with a recent column version that supports -n you can use this alternative: perl -pe 's/(^|;);/$1 ;/g' file.csv | column -ts\; | less -S Change the delimiter to your liking.

Print every Nth line
Sometimes commands give you too much feedback. Perhaps 1/100th might be enough. If so, every() is for you. $ my_verbose_command | every 100 will print every 100th line of output. Specifically, it will print lines 100, 200, 300, etc If you use a negative argument it will print the *first* of a block, $ my_verbose_command | every -100 It will print lines 1, 101, 201, 301, etc The function wraps up this useful sed snippet: $ ... | sed -n '0~100p' don't print anything by default $ sed -n starting at line 0, then every hundred lines ( ~100 ) print. $ '0~100p' There's also some bash magic to test if the number is negative: we want character 0, length 1, of variable N. $ ${N:0:1} If it *is* negative, strip off the first character ${N:1} is character 1 onwards (second actual character).

generate iso

chmod - change file permissions of a file to be similar of another

Backup trought SSH


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