k-nut/knowledge.md

## knowledge.md

      
    Raw
  

              knowledge.md
            
          
    vim


<n>G to jump to nth row
ctrl+o to jump to last curor position
ctrl+n to highlight word, again to jump to next one, ctrl-x to skip one ctrl-p to go back-

with plugin: c to change the selection


q: to get a window of all last commands <CR> to execute them
J to move the following line to the end of this line
<leader>s to substitute word under cursor
"<char>dd deleted line into register
"<char>p pastes file from register
:s/\%V\(.*\)\%V/<a href="#\1">\1<\/a>/ to surround visual selection
:nohlsearch to no longer highlight search matches
:grep <word> to find. then :cw in search results to open in quickfix window
ctrl+a increments the next number by one, ctrl+x decrements it http://vim.wikia.com/wiki/Increasing_or_decreasing_numbers
:e <path e.g. "."> opens a file browser that can be searched and used to edit files

zsh


ctrl+r to serach history
ctrl+l to replace clear
ctrl+z to suspend process, bg to list them, fg to bring it back to the foreground, disown to separate process from terminal
$? holds the exit status of the last executed command
^foo^bar takes the last command from the history and replaces foo with bar

unix command line tools

- echo {"some": "json"} | python -m json.tool pretty prints json on the cmd line

grep -A12 -B15 gives the matching lines and 12after, 15 before
man 2 open lets you inspect level 2 (system) calls like open
htop has a -d option which lets you set the refesh interval (in tenths of seconds). htop -d 5 sets it to two times a second
less -S turns off line wraping which is useful if you have long tabular text (like the output of csvlook)
renameutils allows you to easily change file names with the editor that you are used to
sort has the -h flag which sorts by human readble values (such as the one produced by du -h) which might include KB, MB etc

python


dir() shows all properties/methods of an object
ptpython is a nice command line replacement for ipython
import ipdb; ipdb.set_trace() gives you an interactive debugging session
ctrl + [ or ctrl + ] to indent/unindent in ipython 
_ gives you the last evaluted result in (i)Python, __ the second last and so on
You can user python -c to execute python lineline in a shell. Example: echo 'hello cool arguments '  | python -c 'import sys; print sys.stdin.read().split()'
IPython's input mode can be switched to vim or emacas mode. To switch it to vim mode create a config file (ipython profile create) and set c.TerminalInteractiveShell.editing_mode = 'vi' in the ipython_config.py file that is created. Then you can hit escape and move around like you are used to from vim. (reference)1

Browser devtools

inspect($(".points")) in the console to select the element in the Elements panel
debug(YourLibrary.someFunction) or monitor(YourLibrary.someFunction) to be notified when function is called
Webdevelopment

Change describe or it to fdescdribe or fit to only run those tests with jasmine
Git


git reset --soft origin/master

This will rollback your branch to the same commit as origin/master but it keeps all the changes you have done


git stash --patch to let you choose what you want to stash and what not
git bisect and then git good or git bad to go on the hunt for a bug in the history
Add -S to git commit (as in git commit -S -m 'my signed commit') to use GPG to sign your commit. It will then show up with a checkmark on the     github.com///commits page
diff so fancy for nicer highlighting and colors in diffs

psql


\e to edit the last executed command in default text editor
run \watch after a query to run this query every two seconds (just like the default unix watch)

tools


alex checks text for non inclusive language
httpie Replaces wget/curl
webcoach to measure performance of webpages and get advice
tldr as an example-driven alternative to man
thefuck corrects commands that you mistyped in the console

macOS


sudo ifconfig en0 ether aa:bb:cc:dd:ee:ff to change mac address of wifi card (useful if throttled by mac address) (maybe make sure to store your original one and reset back to it after you are done to avoid side effects)
⌘-E finds currently selected text (in some tools)
Apple has a long support doucment on keyborad shortcuts

heroku


heroku pg:ps to see all running postgres processes
heroku pg:killall to kill all running postgres processes

fish


alt-e to edit the current line in $EDITOR (see this commit)

JetBrains Editors


The Rainbow Brackets Plugin colorizes matching parantheses

iTerm2


if you install the iTerm2 shell integration you get convenient features such as being able to jump back
to the previous command in the history with cmd-shift-up (reference)2