Memorising These Regular Expressions would be very helpful for this lab by INE.
+——————————————————+
| CHAR | USAGE |
+——————————————————|
| ^ | Start of string |
|——|———————————————–|
| $ | End of string |
|——|———————————————–|
| [] | Range of characters |
|——|———————————————–|
| – | Used to specify range ( i.e. [0-9] ) |
|——|———————————————–|
| ( ) | Logical grouping |
|——|———————————————–|
| . | Any single character |
|——|———————————————–|
| * | Zero or more instances |
|——|———————————————–|
| + | One or more instance |
|——|———————————————–|
| ? | Zero or one instance |
|——|———————————————–|
| _ | Comma, open or close brace, open or close |
| | parentheses, start or end of string, or space |
+——————————————————+
+————-+—————————+
| Expression | Meaning |
|————-+—————————|
| .* | Anything |
|————-+—————————|
| ^$ | Locally originated routes |
|————-+—————————|
| ^100_ | Learned from AS 100 |
|————-+—————————|
| _100$ | Originated in AS 100 |
|————-+—————————|
| _100_ | Any instance of AS 100 |
|————-+—————————|
| ^[0-9]+$ | Directly connected ASes |
+————-+—————————+
nocsma 
Memorising These Regular Expressions would be very helpful for this lab by INE.
+——————————————————+
| CHAR | USAGE |
+——————————————————|
| ^ | Start of string |
|——|———————————————–|
| $ | End of string |
|——|———————————————–|
| [] | Range of characters |
|——|———————————————–|
| – | Used to specify range ( i.e. [0-9] ) |
|——|———————————————–|
| ( ) | Logical grouping |
|——|———————————————–|
| . | Any single character |
|——|———————————————–|
| * | Zero or more instances |
|——|———————————————–|
| + | One or more instance |
|——|———————————————–|
| ? | Zero or one instance |
|——|———————————————–|
| _ | Comma, open or close brace, open or close |
| | parentheses, start or end of string, or space |
+——————————————————+
+————-+—————————+
| Expression | Meaning |
|————-+—————————|
| .* | Anything |
|————-+—————————|
| ^$ | Locally originated routes |
|————-+—————————|
| ^100_ | Learned from AS 100 |
|————-+—————————|
| _100$ | Originated in AS 100 |
|————-+—————————|
| _100_ | Any instance of AS 100 |
|————-+—————————|
| ^[0-9]+$ | Directly connected ASes |
+————-+—————————+