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Bash's history expansion character, "!", has many features, including "!:" for choosing a specific argument (or range of arguments) from the history. The gist is any number after !: is the number of the argument you want, with !:1 being the first argument and !:0 being the command. See the sample output for a few examples. For full details search for "^HISTORY EXPANSION" in the bash(1) man page.
Note that this version improves on the previous function in that it handles arguments that include whitespace correctly.
Exactly the same effect with 3 less characters ;-) (Removes all files/filesystems of a harddisk. It removes EVERYTHING of your hard disk. Be careful when to select a device.)
You can press Ctrl + C after few seconds
This particular combination of flags mimics Try CoffeeScript (on http://coffeescript.org/#try:) as closely as possible. And the `tail` call removes the comment `// Generated by CoffeeScript 1.6.3`.
See `coffee -h` for explanation of `coffee`'s flags.
Simple and easy to remember, if it already exists then it just ignores it.
This command is similar to the above, but is much simpler to remember. Sure, it's isn't as precise as the parent command, but most people aren't going to remember those --flags anyways unless you stick it into your .bashrc on every single system that you manage.
shorter (thus better ;-)
Assumed dir A, B, C are subdirs of the current dir
Exact syntax of the command is:
rsync -v -r --size-only --compare-dest=/path_to_A/A/ /path_to_B/B/ /path_to_C/C/
(do not omit end-slashes, since that would copy only the names and not the contents of subdirs of dir B to dir C)
You can replace --size-only with --checksum for more thorough file differences validation
-n, --dry-run perform a trial run with no changes made
Must have rabbitmqctl: https://www.rabbitmq.com/man/rabbitmqctl.1.man.html
See connections as the change, by user, sorted.
Same as the rest, but handle IPv6 short IPs. Also, sort in the order that you're probably looking for.
[Click the "show sample output" link to see how to use this keystroke.]
Meta-p is one of my all time most used and most loved features of working at the command line. It's also one that surprisingly few people know about. To use it with bash (actually in any readline application), you'll need to add a couple lines to your .inputrc then have bash reread the .inputrc using the bind command:
echo '"\en": history-search-forward' >> ~/.inputrc
echo '"\ep": history-search-backward' >> ~/.inputrc
bind -f ~/.inputrc
I first learned about this feature in tcsh. When I switched over to bash about fifteen years ago, I had assumed I'd prefer ^R to search in reverse. Intuitively ^R seemed better since you could search for an argument instead of a command. I think that, like using a microkernel for the Hurd, it sounded so obviously right fifteen years ago, but that was only because the older way had benefits we hadn't known about.
I think many of you who use the command line as much as I do know that we can just be thinking about what results we want and our fingers will start typing the commands needed. I assume it's some sort of parallel processing going on with the linguistic part of the brain. Unfortunately, that parallelism doesn't seem to work (at least for me) with searching the history. I realize I can save myself typing using the history shortly after my fingers have already started "speaking". But, when I hit ^R in Bash, everything I've already typed gets ignored and I have to stop and think again about what I was doing. It's a small bump in the road but it can be annoying, especially for long-time command line users. Usually M-p is exactly what I need to save myself time and trouble.
If you use the command line a lot, please give Meta-p a try. You may be surprised how it frees your brain to process more smoothly in parallel. (Or maybe it won't. Post here and let me know either way. ☺)
It takes a byte from /dev/random whose source is the kernel entropy pool (better source than other solutions).
This gets the Nth argument in the last line of your history file. This is useful where history is being written after each command, and you want to use arguments from the previous command in the current command, such as when doing copies/moving directories etc.
I wrote this after getting irritated with having to continually type in long paths/arguments.
You could also use $_ if all you want is the last argument.
If you need to delete lines that may contain space characters (such as tabs or spaces) as well as empty ones, try:
Just an alternative.
Searches bash-history in reverse order (last entered commands first). Pressing ctrl+r again shows the next matching entry.
The first sort is necessary for ips in a list to be actually unique.
greps your bash history for whatever you type in at the end returning it in reverse chronological order (most recent invocations first), should work on all distros.
works well as an alias