rubbsdecvik/tips.md

## tips.md

      
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    MORE TRICKS

I have another document with some other tricks we didn't cover last night here: https://gist.github.com/rubbsdecvik/431adebd1daa2aecfcc333d3a433e9c4
You can use !! to substitute a previous command

For example:
Run a command.
input:
whoami
output:
pregan
Then use !! to substitute:
input:
sudo !!
output:
root
Use ^search^replace to substitute a string from previous command

Run a command:
input:
echo foo
output:
foo
Then use ^foo^bar to swap the string
input:
^foo^bar
This will change the command to echo bar.
output:
bar
Fix commands with fc

You can put a command into your editor with fc which will put the previous command into an editing session. Once you save and quit, it will execute the contents of your editor buffer.
Use Pipeviewer to see a progress bar

First you will need to install pv
On Fedora systems:
sudo dnf install pv
On Red Hat systems:
sudo yum install pv
On Debian/Ubuntu:
sudo apt install pv
Then you can use it anywhere you can use cat but the stderr will now contain a progress bar.
For example:
pv Downloads/Fedora-Workstation-Live-x86_64-24-1.2.iso > /dev/null
Use !$ to reuse the last argument in a command

Run a command
input:
mkdir devops
Then use `!$! to get the last "word" from the previous command
input:
cd !$
This will change directories to devops
Use Grep's options brackets to avoid an extraenous grep -v

When you are grepping through a list of ps output, you will match on the very search you're making.
input:
ps aux | grep bash
output:
pregan    6925  0.0  0.0 133788  4976 pts/13   Ss   Feb17   0:00 bash
pregan    7672  0.0  0.0 119376   960 pts/11   S+   12:47   0:00 grep --color=auto bash
pregan    9390  0.0  0.0 134304  5672 pts/7    Ss+  Mar02   0:00 -bash

You can remove that by using [] within your grep search.
input:
ps aux | grep [b]ash
output:
pregan    6925  0.0  0.0 133788  4976 pts/13   Ss   Feb17   0:00 bash
pregan    9390  0.0  0.0 134304  5672 pts/7    Ss+  Mar02   0:00 -bash

Aliases can be useful for common commands

You can use alias to see a list of your aliases and then how to use the alias command to create new ones.
One useful one is:
alias bel='tput bel'
After this alias has been created, you then can use the command bel to make your terminal make a noise.
Use tmux to have a disconnectable terminal multiplexer

Tmux is a multiplexer, which just means it can act as multiple terminals inside the same terminal session. This is very helpful if you are connected via ssh. You can learn more about Tmux here.