## Your frenemy # The Command Prompt [gregorymcintyre.com](https://gregorymcintyre.com) 2016 ==== ## The Command Prompt - Purpose - Anatomy - Get unstuck - Get happier ==== ## Purpose What do I use the command prompt for? I don't know, let's ask it. ```small man cut man uniq man sort man head cut -f1,2 -d ' ' ~/.bash_history \ | sort | uniq -c | sort -nr | head -n 30 ``` ==== ## Purpose Honest answer time: ```small git status ls git add git diff git grep git commit git push cd .. git log git checkout cd npm i git pull git rebase git stash git reset ``` ==== ## Purpose Mostly: Git ```small git status (gs) git add git diff git grep git commit git push git log git checkout git pull git rebase git stash git reset ``` ==== ## Purpose Frequently: Development Framework Commands ``` rails new myapp rails g model Blog title:string rails console rails db rails s rails routes rails db:setup rails db:migrate ``` ==== ## Purpose Frequently: Development Framework Commands ``` node . nodemon npm start gulp yo sequelize deargodwhy ``` ==== ## Purpose Less Frequently: Package Management ``` bundle init bundle upgrade gem install npm init npm install ``` ==== ## Purpose Less Frequently: Package Management ``` brew update brew upgrade brew install apt-get install yum install ``` ==== ## Purpose Rarely: Deal With It ```small git log $(git merge-base master branch)..branch cut -f1,2 -d ' ' ~/.bash_history \ | sort | uniq -c | sort -nr | head -n 30 wget -mk http://www.stuff.to/read/on/the/train/ rsync -rvP myproject/ username@myhost/myproject.com/ pg_dump --clean -Z 9 app_master | \ ssh user@apphost 'zcat | psql -h localhost -U app appdb' ``` ==== ## The Command Prompt - ~~Purpose~~ - Anatomy - Get unstuck - Get happier ==== <!-- .slide: data-transition="fade-out" --> <img class="borderless" src="term-running-middleman.png" alt="Terminal running middleman"> ==== <!-- .slide: data-transition="fade-in" --> <img class="borderless" src="term-running-middelman-hl.png" alt="Terminal running middleman with highlights"> ==== `$ pstree` ```small \-+= 73533 greg iTerm2 --server login -fp greg \-+= 73534 root login -fp greg \-+= 73535 greg -bash \-+= 73987 greg ruby middleman <pid> <user> <program> <arguments> ``` (`brew install pstree`) ==== ## Terminal Emulator - AKA terminal or just "term" - GUI app - Runs programs that use only text for input & output - By default, runs a **shell** ==== ## Terminal Emulators - Terminal - iTerm - cmd.exe - xfce4-terminal - gnome-terminal - konsole - xterm - rxvt ==== ## Emulator? <img class="borderless" src="bios.jpg" alt="BIOS"> ==== ## TTY? ``` Last login: Thu Aug 4 10:40:25 on ttys002 -----------------------------------^^^^^^^ ``` TTY = **tele-typewriter**, a word used for the input/output portion of early computing devices ==== ## Console? - Named after the piece of furniture - Implies a keyboard and a screen of text ==== ## Bash - sh (Ye Olde Bourne shell) - bash (Bourne**-Again** shell) - zsh (from author Zhong Shao) - csh (shell with C language syntax) - tcsh (TENEX OS version of csh) - cmd.exe ==== ## Shell? - Have... program pearls... inside of them? - Usually 1. Print prompt 2. Wait for you to type a command 3. Run a program (e.g. `rails s`) 4. Send output back out to terminal emulator until program exits ==== ## Shell modes - Login shells - Non-login shells - Interactive shells - Non-interactive shells ==== - **Login Shells** - Run your terminal emulator app - Loads config from `~/.bash_profile` ``` \-+= 73535 greg -bash ``` ==== - **Non-Login Shells** - Run `bash` at the bash prompt - Loads config from `~/.bashrc` ```small $ bash $ bash $ bash \-+= 82172 greg -bash \-+= 85560 greg bash \-+= 85833 greg bash \-+= 86106 greg bash ``` ==== - **Interactive Shells** - `bash` - Print prompt, read from keyboard, etc. - **Non-Interactive Shells** - `bash myscript.sh` - No prompts, still loads `.bashrc` ==== ## .bash_profile? I actually have no idea why it's called that ==== ## .bashrc? `bash` is the program and `-rc` is a suffix that means configuration. ==== ## You're bashitting me `-rc` means configuration? It's short for `runcom` which was a configuration tool in an OS precursor to Unix/Linux/MacOS ==== ## Command Prompt Just text that a **shell** prints before it waits for your input ``` greg@rascal ~$ rascal% C:\> ``` ==== ## Commands ```small man rsync rsync -avuzb --exclude '*~' samba:samba/ . 'rsync' '-avuzb' '--exclude' '*~' 'samba:samba/' '.' ``` ==== ## Quoting `cut -f1,2 -d ' ' ~/.bash_history` `cd 'VirtualBox VMs'` ==== ## Quoting and Escaping ```small man find $ find . -name *.js -exec cat {} ; # 1st attempt find: -exec: no terminating "" or "+" $ find . -name *.js -exec cat {} \; # escape ; find: reveal.js: unknown primary or operator $ find . -name '*.js' -exec cat {} \; # quote * $ find . -name \*.js -exec cat {} \; # escape * ``` ==== ## Pipes and redirects - **stdin**: Input (e.g. your keyboard) - **stdout**: The good news - **stderr**: The bad news ==== ## Pipes Connect the output stream of one program to the input stream of another `cut -f1,2 -d ' ' ~/.bash_history | sort | uniq -c | sort -nr | head -n 30` ==== ## Redirect Connect the output stream of a program to a file `unicorn > unicorn.log` `unicorn 2> unicorn_errors.log` ==== ## Redirect to another stream Send errors into the output stream `(rspec 2>&1) | less -R` ==== ## The Command Prompt - ~~Purpose~~ - ~~Anatomy~~ - Get unstuck - Get happier ==== **I ran `rails s` and now I don't have a prompt anymore** - `Control-C` sends an **interrupt signal** to the currently running program asking it politely to stop ==== **What if my program doesn't exit?** - `Control-Z` suspends the program and puts you back on the command prompt - Then run this `kill -9 %` ==== `kill -9 %` - Signal 9 force-quits the program - `%` is a bash code for the "pid of the last program you suspended" - `man kill` ==== **I ran `psql/irb/pry/node` and I can't get out!** - exit, quit, q, mashing escape, nothing works - `Control-D` sends the **hangup signal** to an interactive prompt program and is the most universal way to exit any prompt ==== **I press keys and nothing happens or garbage gets printed** - Some programs print special codes that move the cursor or change colour - Interrupting such programs can leave your terminal in a broken state - Quit your terminal emulator and start a new one - Examine `ps ax` output and `kill` anything you don't want running ==== **Where do I get help?** - Read the manual (man = manual, spacebar for next page, q to quit) `man wget` - Ask a program to print help for you `rails --help` - Universal solution: - Google "wget command" or "rails command" ==== <img src="xkcd-flowchart.png" alt="XKCD Flowchart"> ==== ## The Command Prompt - ~~Purpose~~ - ~~Anatomy~~ - ~~Get unstuck~~ - Get happier ==== ## Nicer Prompts ```tiny red="\[\033[01;31m\]" green="\[\033[01;32m\]" yellow="\[\033[01;33m\]" blue="\[\033[01;34m\]" pink="\[\033[01;35m\]" cyan="\[\033[0;36m\]" gray="\[\033[01;30m\]" reset="\[\033[00m\]" user_and_host='\u@\h' rvm='$([ -f .rvmrc ] && [ $PWD != $HOME ] && echo "" $(~/.rvm/bin/rvm-prompt i v g))' git='$(/usr/bin/ruby -e '\''print `git branch 2> /dev/null`.match(/\*(.+)$/).to_a.last.to_s'\'')' dir=' \w' date='$(date +%T)' PS1="${green}${user_and_host}${cyan}${rvm}${yellow}${git}${blue}${dir}${reset}\n${gray}${date}${reset} \$ " ```  ==== ## Aliases `echo "alias gs='git status'" >> ~/.profile` ==== ## Colour `echo "alias ls='ls -ohG'" >> ~/.profile`  ==== ## Colour ALL the programs \o/ `git config --global color.ui true`  ==== ## Beginner Tips - Don't panic - Commands: cd, cd .., pwd, ls - Keys: Up, Down, Tab ``` $ atom ind<Tab> $ atom index.html ``` ==== ## Intermediate Tips - **Control-A**: start of the line
 - **Control-E**: end of the line
 - **Alt-Delete**: delete previous word ==== ## Intermediate Tips Terminal, Chrome, Sublime, Evernote, Keynote, XCode, Pages, LibreOffice, System Preferences, Gnome, KDE, XFCE5, Windows  ==== ## Intermediate Tips - **Alt-B**: move back one word - **Alt-F**: move forwards one word - **Alt-D**: delete next word - **Control-K**: delete to the end of the line - **Control-R**: search for a previous command ==== ## Configure Terminal  ==== ## Configure iTerm  ==== ## Configure Terminal/iTerm Only recommended on US keyboards :-( ==== ## Intermediate Tips - Search with Control-R - Control-R to start - Start typing (e.g. type “git r”) - Control-R to jump to next oldest match - Control-S to jump to next newest match - Return to run, Esc to cancel ==== ## Advanced Tips Customise readline ```small $ cat ~/.inputrc # Be quiet set bell-style visible # We are using a UTF terminal set convert-meta on # Better than Control-R M-n: history-search-forward M-p: history-search-backward ``` ==== ## Advanced Tips   ==== ## Advanced Tips ```small $ cat ~/bin/v #!/bin/sh exec gvim --remote-expr \ "expand('%').':'.line('.')" $ v myfile.rb:20 $ rspec `v` ``` ==== ## Advanced Tips Other editors... ```small exec emacsclient --eval ' (with-current-buffer (window-buffer (selected-window)) (concat (buffer-file-name) ":" (number-to-string (line-number-at-pos)))) ' | sed s'/^\"\(.*\)\"$/\1/' ``` ==== ## Advanced Tips <img class="borderless" src="command-r-iterm-trick.png" alt="Command-R in iTerm"> ==== ## Advanced Tips Or you can get bash or zsh to evaluate it... ``` $ rspec <Command-R> $ rspec `v`<Control-Alt-E> $ rspec killer_feature_spec.rb:28 % rspec <Command-R> % rspec `v`<Tab> % rspec killer_feature_spec.rb:28 ``` ==== ## The Command Prompt - ~~Purpose~~ - ~~Anatomy~~ - ~~Get unstuck~~ - ~~Get happier~~ ==== [gregorymcintyre.com/slides/command-prompt/](https://gregorymcintyre.com/slides/command-prompt/#/)