tips.md

Tips and Tricks

Virtual Console

• Scroll up: Shift + PgUp
• Scroll down: Shift + PgDown
• History: cat /dev/vcsu
• You can get a copy of the text off the machine with:
  • mkdir www
  • cd www
  • cp /dev/vcsu .
  • ip a and take a note of the IP address.
  • srvfiles -h 0.0.0.0 -p 80
  • Then on the same LAN, open http://192.168.x.y/vcsu in a web browser.

Setting up Vim for Go

Here are some quick instructions for installing https://github.com/fatih/vim-go

# First install the vim plugin manager:
curl -fLo ~/.vim/autoload/plug.vim --create-dirs https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim

# Add the vim-go plugin to the vimrc:
echo "call plug#begin('~/.vim/plugged')" >> ~/.vimrc
echo "Plug 'fatih/vim-go', { 'do': ':GoUpdateBinaries' }" >> ~/.vimrc
echo "call plug#end()" >> ~/.vimrc

# Install the plugins:
vim +PlugInstall

See the Run-It/Build-It/Fix-It/Test-It/... sections in https://github.com/fatih/vim-go/wiki/Tutorial

You can setup shortcuts in your vimrc like this:

map <F3> :GoBuild<CR>
map <F4> :GoTest<CR>

Running Go Debugger (Delve)

This depends on the previous steps to setup Go for Vim.

Adding this line to your vimrc makes the experience better:

echo "let g:go_debug_log_output = 0" >> ~/.vimrc

1. Start the debugger with :GoDebugStart.
2. Set a breakpoint on the current line with :GoDebugBreakpoint or <F9>.
3. Run to the breakpoint with :GoDebugContinue or <F5>.
4. You should see the following windows:
   • STACKTRACE: Hit enter on any of these to jump to the code.
   • VARIABLES: Local variables, arguments and registers
   • GOROUTINES: Hit enter on any of these to jump to the code.
   • OUTPUT: Output from the program and dlv
5. Use these commands to navigate your code (see :help GoDebugStart):
   • :GoDebugNext or <F10>: Run to next line in the current function
   • :GoDebugStep or <F11>: Run to next line which may be in another function (due to a function call).
   • :GoDebugStepOut: Run until the current function returns
   • :GoDebugSet {var} {value}: Only works for ints, bool, float and pointers.
   • :GoDebugPrint {expr}: Print the result of the expression.
   • <F6>: Print the value of word under the cursor.
6. Stop the debugger with :GoDebugStop.

Dumping Stack Trace of Go Program

1. Use CTRL-Z to move the process to background.
2. Send the ABRT signal kill -ABRT %1
3. Resume the job with fg.