ruby.md

   1 ---
   2 title: Ruby
   3 category: Ruby
   4 tags: [WIP]
   5 layout: 2017/sheet
   6 intro: |
   7   Quick reference to some features of the Ruby programming language.
   8 ---
   9
  10 ### Reference
  11
  12 {:.-one-column}
  13
  14 | Code                    | Description                                               |
  15 | ----------------------- | --------------------------------------------------------- |
  16 | `$!`                    | latest error message                                      |
  17 | `$@`                    | location of error                                         |
  18 | `$_`                    | string last read by gets                                  |
  19 | `$.`                    | line number last read by interpreter                      |
  20 | `$&`                    | string last matched by regexp                             |
  21 | `$~`                    | the last regexp match, as an array of subexpressions      |
  22 | `$n`                    | the nth subexpression in the last match (same as `$~[n]`) |
  23 | `$=`                    | case-insensitivity flag                                   |
  24 | `$/`                    | input record separator                                    |
  25 | `$\`                    | output record separator                                   |
  26 | `$0`                    | the name of the ruby script file                          |
  27 | `$*` (or `ARGV`)        | the command line arguments                                |
  28 | `$$`                    | interpreter's process ID                                  |
  29 | `$?`                    | exit status of last executed child process                |
  30 | `$-i` `$-l` `$-p` `$-v` | Command line switches                                     |
  31 | `$-v` (or `$VERBOSE`)   | verbose mode                                              |