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cat a
a
b
c
d
e
cat b
c
d

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openssl x509 -noout -modulus -in server.crt| openssl md5
openssl rsa -noout -modulus -in server.key| openssl md5
# really cool feature of openssl
openssl s_server -cert server.crt -key server.key
# if the keys don't match you will get an error message

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string_with_newlines='a
b
c'
echo $string_with_newlines |tr -s '\n' ' '
a b c

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Sorting cmd output by column with the sort command

Some commands come with their own sorting functionality. Anyhow it's an useful flag to have in your repertoire

So let's say we want to sort by VSZ and we have this output.

[azureuser@alma ~]$ ps aux |head -5
USER         PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root           1  1.5  0.1 175056 13480 ?        Ss   19:24   0:01 /usr/lib/systemd/systemd --switched-root --system --deserialize 16
root           2  0.0  0.0      0     0 ?        S    19:24   0:00 [kthreadd]
root           3  0.0  0.0      0     0 ?        I<   19:24   0:00 [rcu_gp]

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To look through all man pages for a string there are two options

1. loop through the manpages files with find, xargs and zgrep:

find $(manpath|tr ':' ' ') -type f -print0 | xargs -0 zgrep -i '\.config/systemd'

2. simply use man -K notice the capital K:

man -K '.config/systemd'

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set ts=2 sw=2 sts=2 
set et 
set nu ru 
set ai si 
set hlsearch
syntax on 
filetype plugin indent on 

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Creates an example ansible-navigator.yml config:

ansible-navigator settings --sample > ansible-navigator.yml

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#!/bin/bash
# define var in script
GREETING="Welcome"
echo GREETING
echo $GREETING

# pass var as arg
echo "you have typed $1 as the first argument"
echo "these are all arguments: $@"