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GitarPlayer / variables.sh
Created August 8, 2023 19:20
Chapter 1 script components
View variables.sh
#!/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: $@"
View Useful commands for EX374.md

Creates an example ansible-navigator.yml config:

ansible-navigator settings --sample > ansible-navigator.yml
View simple yaml .vimrc
set ts=2 sw=2 sts=2
set et
set nu ru
set ai si
set hlsearch
syntax on
filetype plugin indent on
View man_pages_grep.md

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'
  1. simply use man -K notice the capital K:
man -K '.config/systemd'
View sort.md

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]
@GitarPlayer
GitarPlayer / tr.md
Created March 31, 2022 07:13
replace all newlines with a space with tr and -s squeeze option
View tr.md
string_with_newlines='a
b
c'
echo $string_with_newlines |tr -s '\n' ' '
a b c
@GitarPlayer
GitarPlayer / cert.md
Created March 4, 2022 08:57
verify tls key and cert match
View cert.md
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
@GitarPlayer
GitarPlayer / grep.md
Last active March 4, 2022 08:51
grep that compares two configs a and b and finds all config lines present in file a and not in b. Of course a diff could do that, but sometimes you don't want to deal with the order or the differences of whitespaces. between the configs.
View grep.md
cat a
a
b
c
d
e
cat b
c
d