Notes.

General notes that I may need in future and I don’t know where to put them in Notes.app 📝

Shell Commands

ZSH (oh-my-zsh)

• cd to history

    dirs -v
    cd -<TAB>
  

SSH

• show ssh key fingerprint:

    ssh-keygen -lf .ssh/id_rsa.pub
  

• generate keys:

    ssh-keygen -f ~/keyfile -t ecdsa -b 521
  

SHELL/BASH

• add prefix to the beginning of a line

    # If you want to edit the file in-place
    sed -i -e 's/^/prefix/' file
    # If you want to create a new file
    sed -e 's/^/prefix/' file > file.new
  

• read file by line

    while IFS= read -r line
      do
      # script
    done < file.txt
  

• grep and display only requested string/regex

    grep -Po 'Your support ID is: [0-9]+'
  

• run a simple http server

    python3 -m http.server --cgi 8080
  

• convert encoding

    iconv --list
    iconv -f CP1250 -t UTF-8 Movie.srt > Movie.utf8.srt
  

Makefile

• basic syntax:

    build:
    <TAB>command
    <EMPTY LINE>
  

• Check whether the TAB are correctly set:

    cat -e -t -v makefile_name
  

VIM

• Integrate with system clipboard:
  • copy selected part: visually select text(type v or V in normal mode) and type :w !pbcopy
  • copy the whole file :%w !pbcopy
  • paste from the clipboard :r !pbpaste

cURL

• Resolve a hostname to custom IP:

    curl --resolve lubos.klokner.sk:443:127.0.0.1 https://lubos.klokner.sk/
  

• Do not check the certificate:

    curl -k https://lubos.klokner.sk/
  

• Read data from a file:

    # file.txt: param1=value1&param2=value2
    curl -G 'http://example.com/' -d @file.txt
    curl -G 'http://example.com/' --data-urlencode @file.txt
  

• Send Cookie:

    curl -b 'flag6=COOKIE_VALUE8; expires=Mon, 2 Aug 2021 20:20:20 UTC; path=/' https://lubos.klokner.sk/
  

VSCODE

• Multi-Line editing:  + fn + f2
• Duplicate lines of code in both directions: shift + alt + arrow up/down
• Move line: alt + arrow up/down
• Comment:  + /

macOS

VMware Fusion

• Fix networking issues:

    sudo /Applications/VMware\ Fusion.app/Contents/Library/vmnet-cli --stop
    sudo /Applications/VMware\ Fusion.app/Contents/Library/vmnet-cli --start
  

Networking

• Allow packet forwarding:

    sudo sysctl -w net.inet.ip.forwarding=1
  

tcpdump

• grep in the network stream:

    sudo tcpdump -A -l dst port 80 | grep "^Cookie:"
  

Docker

Markup Cheat Sheet

F5 BIG-IP

• tcpdump:

    tcpdump -vvv -nni 0.0:nnn "(host [client_ip] and host [VS_ip]) or host [pool_member_ip]" -s0 -w /var/tmp/case_description.pcap
  

• license from CLI:

    get_dossier -b "base key" -a "actkey1,actkey2"
    # goto -> https://activate.f5.com & paste the dossier here
    # copy the license from the webpage
    cat - > /config/bigip.license
    # CTRL + D
    reloadlic
  

• reset to factory defaults (v13.0+):

    tmsh load /sys config default
    tmsh save /sys config partitions all