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Runs previous command replacing foo by bar every time that foo appears
To replace foo by bar, but not execute, do ^foo^bar^:p To replace all foo by bar, but not execute, do ^foo^bar^:&:p

convert unixtime to human-readable with awk
- convert unixtime to human-readable with awk - useful to read logfiles with unix-timestamps, f.e. squid-log: sudo tail -f /var/log/squid3/access.log | awk '{ print strftime("%c ", $1) $0; }

Draw kernel module dependancy graph.
parse "lsmod" output to "dot" format and pass it to "display". Without perl!

Check if a command is available in your system
Usefull to detect if a commad that your script relies upon is properly installed in your box, you can use it as a function function is_program_installed() { type "$1" >/dev/null } Invoke it and check the execution code is_program_installed "dialog" if [ ! $? -eq 0 ]; then echo "dialog is not installed" exit 1 fi

[vim] Clear trailing whitespace in file
% acts on every line in the file. \s matches spaces. \+ matches one or more occurrences of what's right behind it. Character '$' matches end-of-line.

Check your bash shell for vulnerability to the ShellShock exploit
If this command prints 'x' then your shell is vulnerable. Null output confirms that you are protected. Further reading: http://allanmcrae.com/2014/09/shellshock-and-arch-linux/

rsync instead of scp
The command copies a file from remote SSH host on port 8322 with bandwidth limit 100KB/sec; --progress shows a progress bar --partial turns partial download on; thus, you can resume the process if something goes wrong --bwlimit limits bandwidth by specified KB/sec --ipv4 selects IPv4 as preferred I find it useful to create the following alias: alias myscp='rsync --progress --partial --rsh="ssh -p 8322" --bwlimit=100 --ipv4' in ~/.bash_aliases, ~/.bash_profile, ~/.bash_login or ~/.bashrc where appropriate.

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Alias TAIL for automatic smart output
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.

List all files modified by a command
This lists all files modified after calling some command using a temporal anchor.


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