CONSTANT_NAME variable_name ClassName functionName
Naming things is cheap--have DESCRIPTIVE NAMES. It should read as close to natural language as possible, avoiding abbrevs. and in-house language when possible.
Functions should have one thing they do. Endeavor to have pure functions, so that they do not have side effects. Functions should be have a maximum of three arguments. Good functions have one or two.
Avoid being clever and implicit whenever possible.
| class Thing | |
| def initialize | |
| @phase = 1 | |
| @values = [7, 11] | |
| @other_values = [2, 3, 12] | |
| end | |
| def do_it | |
| going = true | |
| while going |
| # Developers are a tricksey bunch. Name some reasons why you shouldn't just trust the person who wrote the code. | |
| # Name some mental pitfalls that you should watch out for when testing code. | |
| # So then, why shouldn't we be satisfied with testing our own code? | |
| When writing code, it is often hard to see the code from an unbiased perspective. | |
| I can't know exactly what another person who is seeing this code for the first | |
| time will think, or if they will be able to understand it. And I can't think of | |
| everything that might go wrong either. I just spent time making it work a certian | |
| way and have pidgeonholed myself into a certain way of thinking. It's much easier | |
| to get some fresh eyes on the code than it is for me to try to make up for my own |
| # replace characters in a string | |
| s = "string" | |
| puts s.tr('i', 'o') | |
| puts s.tr('string', 'Heroku') | |
| puts s.tr_s('ri', 'u') |
| $ ruby -e 'sleep 1 while true' & | |
| [1] 80604 | |
| $ fg %1 | |
| [1] + 80604 running ruby -e 'sleep 1 while true' | |
| ^Z | |
| [1] + 80604 suspended ruby -e 'sleep 1 while true' | |
| $ ps | |
| PID TTY TIME CMD |
| # check current free space | |
| $ df -h | |
| Filesystem Size Used Avail Capacity iused ifree %iused Mounted on | |
| /dev/disk0s2 233Gi 74Gi 158Gi 32% 19571865 41464807 32% / | |
| devfs 221Ki 221Ki 0Bi 100% 767 0 100% /dev | |
| map -hosts 0Bi 0Bi 0Bi 100% 0 0 100% /net | |
| map auto_home 0Bi 0Bi 0Bi 100% 0 0 100% /home | |
| /dev/disk1s2 8.0Mi 1.9Mi 6.1Mi 24% 481 1557 24% /Volumes/Adobe Reader Installer | |
| /dev/disk2s2 3.7Mi 1.9Mi 1.9Mi 50% 477 480 50% /Volumes/SDL | |
| /dev/disk3s2 11Mi 7.8Mi 2.9Mi 74% 1993 730 73% /Volumes/SDL2_mixer |
| # why is sudo necessary? | |
| to run commands that affect the entire system, or exist outside of any | |
| particular user's home directory | |
| # why is sudo dangerous? | |
| Using sudo, it's possible to delete vital files, directories, or even your | |
| entire system. e.g. "sudo rm -rf /" Don't try this at home. Essentially any | |
| command which is non-reversible is potentially dangerous. |
| # Create file | |
| $ touch /tmp/file.tmp | |
| $ l /tmp/file.tmp | |
| -rw-r--r-- 1 jmeyer1 wheel 0B Jun 16 15:59 /tmp/file.tmp | |
| # Change owner to root | |
| $ sudo chown root /tmp/file.tmp | |
| $ l /tmp/file.tmp | |
| -rw-r--r-- 1 root wheel 0B Jun 16 15:59 /tmp/file.tmp |
| $ touch jmeyer.txt | |
| $ scp jmeyer.txt cnuapp@vor.dev.cashnetusa.com:/tmp | |
| The authenticity of host 'vor.dev.cashnetusa.com (10.10.212.130)' can't be established. | |
| RSA key fingerprint is 12:05:3d:8c:37:bf:a6:97:4e:e4:d8:ee:33:d1:19:15. | |
| Are you sure you want to continue connecting (yes/no)? yes | |
| Warning: Permanently added 'vor.dev.cashnetusa.com,10.10.212.130' (RSA) to the list of known hosts. | |
| cnuapp@vor.dev.cashnetusa.com's password: | |
| jmeyer.txt 100% 0 0.0KB/s 00:00 | |
| $ rm jmeyer.txt |
| # view environment variables | |
| $ printenv | |
| PATH=/usr/local/heroku/bin:/usr/local/heroku/bin:/Users/jmeyer1/.rbenv/bin:/Users/jmeyer1/code/8b/bin:/Users/jmeyer1/.rbenv/shims:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin | |
| TMPDIR=/var/folders/wz/v_ty7wz108v3tz90gg627nt40000gp/T/ | |
| SHELL=/bin/zsh | |
| HOME=/Users/jmeyer1 | |
| USER=jmeyer1 | |
| LOGNAME=jmeyer1 | |
| SSH_AUTH_SOCK=/tmp/launch-E2mZnk/Listeners | |
| Apple_PubSub_Socket_Render=/tmp/launch-GhVrOe/Render |