Bash Shell For Working

Settings rc files

# .zshrc, .bashrc
$ cat .zshrc

# add identify key to ssh client
ssh-add ~/.ssh/ntnhaatj >/dev/null 2>&1

# alias to search service logs
alias s=journalclt | grep ssh

vim

Display

• :set hlsearch - highlight any matched from searching
• :nohlsearch - disable highlight
• :set number - show line number
• :set relativenumber - show relative line number with cursor
• set default settings

  $ cat ~/.vimrc 
  set number
  set relativenumber
  set hlsearch
  

Navigation

• by word: W, E, B, Option + nav
• by line:
  • 0 - start
  • $ - end
  • :<linenumber> - go to line number
• by file:
  • gg - start of file
  • G - end of file

Editing

• u undo
• ^r redo
• 5dd delete 5 lines
• yy - copy line, dd - cut line, p - paste, vy - enter visual block and copy
• :%s/foo/bar/g - globally replace foo to bar

Searching

• /str - search str, n - next match, N - next match in opposite direction

Windows

• ^wn - new window, :w <name> - save new file as name
• ^wj or ^wk - switch among windows

Useful Unix commands for ETL pipeline

awk

• scan file by lines
• output matched pattern
• useful for transforming structured data from stdin

# output all USER, PID of processes
$ ps aux | awk '{print $1,$2}'

uniq combine with sort

• to aggregate (count) the unique values

$ ps aux | \
    awk '{print $1}' | \    # get the first column from stdin
    sort | \                # sort alphabetically
    uniq -c                 # count two adjacent lines are the same