===== Linux.Bash =====
<code BASH> PS bash/zsh ${SSH_CLIENT+ssh:}${(%):-%m} 

# see to set options https://github.com/ricbra/zsh-config/blob/master/zshrc
setopt no_share_history
setopt histignorespace
setopt histignorealldups
setopt histreduceblanks

</code>

<code BASH>
# check xterm color
msgcat 
</code>
++++ Пример|
{{:linux:linux:bash:pasted:20240214-064440.png}}
++++
<code BASH>
# grep for configuration without comment line
egrep -v "^$|^[[:space:]]*#" /etc/postfix/main.cf
</code>
bash
  * [[https://linuxize.com/post/bash-functions/|bash-functions]]
<code BASH>
# to save some commmand
savecmd () {
  echo "$1" >> /tmp/$(date +%F).txt
}
# using 
savecmd "ansible  proxmox -m apt -a "name=qemu-guest-agent    state=present" --become"

</code>

<WRAP left box 100% >
Jshon - bash json parser  - http://kmkeen.com/jshon/
<code>
# Example пример создания - ниже конструирования объектов
jshon -n {}
  -n {}
    -n {}
      -n {}
        -s "ssh" -i ansible_connection
        -s "ubuntu" -i ansible_user
      -i "10.59.4.11"
    -i "hostvars"
  -i "_meta"
  -n {}
    -n []
      -s "10.59.4.11" -i 0
    -i "hosts"
  -i dockers
    
# результат в виде запускаемой строки
 jshon -n {} -n {} -n {} -n {} -s "ssh" -i ansible_connection -s "ubuntu" -i ansible_user -i "10.59.4.11" -i "hostvars" -i "_meta" -n {} -n [] -s "10.59.4.11" -i 0 -i "hosts" -i dockers
</code>

</WRAP>

<code BASH>
http -hdo ./body httpbin.org/get 2>&1


# выделение и формирование объекта
http https://github.com/ | jq '.[]| select(.number=="059-07-07" or .number=="059-03-08")| {requestId: .requestId, number: .number}'
# jq grep
jq -r '.' | grep 1

# JQ https://gist.github.com/pedroxs/f0ee8c515eea0dbce2e23eea7c048e10
# рекурсивно выделить в json объект в имени которого есть "Mounts" - find key on name and get object 
jq '.. | objects | with_entries(select(.key | contains("Mounts"))) | select(. != {})'
# same, but output propper array
jq '[ .. | objects | with_entries(select(.key | contains("ftp"))) | select(. != {}) ]'
# or
jq 'map( .. | objects | with_entries(select(.key | contains("ftp"))) | select(. != {}) )'
# transform input from {type: a, amount: 1} to {a: 1} and sum all values by type
jq '[ .[] | {(.type): .amount} ] | map(to_entries) | add | group_by(.key) | map({key: .[0].key, value: map(.value) | add}) | from_entries'
# invert selection of contains key name
journalctl -f  -o json | jq -cr 'select(._SYSTEMD_UNIT=="monitorinflux.service"| not ) | {unit:._SYSTEMD_UNIT, mess:.MESSAGE}'
</code>

image magic
<code BASH>
create collage from files 
"C:\Program Files\ImageMagick-7.1.0-Q16-HDRI\magick.exe" montage *.jpg c:\tmp\montage.jpg 
</code>

===== Linux.Admin =====
<code BASH>
# users
$ps auxww
#all full command line 
$ps ewwf
</code>

<code BASH>
# Get process using swap 
$ (echo "COMM:PID:SWAP"; for file in /proc/**/status ; do awk '/^Pid|VmSwap|Name/{printf $2 " " $3}END{ print ""}' $file; done | grep kB | grep -wv "0 kB" | sort -k 3 -n -r ) | column -t | head -50
</code>
<code BASH>
# Asing heredoc to variable Use $() to assign the output of cat to your variable like this:
VAR=$(cat <<'END_HEREDOC'
test 'test"
$(dont-execute-this)
test"test"''
END_HEREDOC
)

# this will echo variable with new lines intact
echo "$VAR"
# this will echo variable without new lines (changed to space character)
echo $VAR
Making sure to delimit starting END_HEREDOC with single-quotes.

</code>
<code BASH>
# monitor directory
watch -n 5  'echo $(date) $(du -d 1 /media/synology-esb-smb/uismv-db-backups/full-backups/temp/)'
</code>
<code BASH>
# SWAP INFO
alias swapi=$(cat <<'END_HEREDOC'
( echo "COMM:PID:SWAP"; for file in /proc/**/status ; do awk '/^Pid|VmSwap|Name/{printf $2 " " $3}END{ print ""}' $file; done | grep kB | grep -wv "0 kB" | sort -k 3 -n -r ) | column -t | head -50
END_HEREDOC
)

</code>

<code BASH>
# find KVM and name of kvm names
 ps axf | grep -oE "(64353|930818|182162|239596|804199|692833|64644|309148|126991).+debug" | grep -Eo " guest=\S+"

</code>
<code BASH>
# Grep exclude comments and blank lines
grep -v '^\s*$\|^\s*\#' temp
</code>


===== Linux move files =====
https://princetonuniversity.github.io/PUbootcamp/sessions/data-transfer-basics/PUBootCamp_20181031_DataTransfer.pdf

- scp
- ftp
- rsync
- GridFTP
- BBCP

===== Scripting =====
  * scripting pitfails https://mywiki.wooledge.org/BashPitfalls#cat_file_.7C_sed_s.2Ffoo.2Fbar.2F_.3E_file


===== Scripting-code =====
  * read line by line - https://phoenixnap.com/kb/bash-read-file-line-by-line

<code BASH>

#!/bin/bash

# Declare variables
vm_name=""
vm_path=""
skipped_lines=""
current_line_number=1

# Read the file line by line
while IFS=';' read -r vm_name vm_path; do
  # Check if the line has the correct format
  if [[ -z "$vm_name" ]] || [[ -z "$vm_path" ]]; then
    skipped_lines="${skipped_lines}Line ${current_line_number}: ${line}\n"
  fi

  # Process the variables here if the line has the correct format
  if [[ -n "$vm_name" ]] && [[ -n "$vm_path" ]]; then
    echo "VM name: $vm_name"
    echo "VM path: $vm_path"
  fi

  # Increment the line number
  current_line_number=$((current_line_number+1))
done < file.txt

# Print the skipped lines
if [[ -n "$skipped_lines" ]]; then
  echo "The following lines were skipped because they did not have the correct format:"
  echo "$skipped_lines"
fi
</code>