Coding 101

Jul 3rd 2014

Coding 101 24

Perl: Command Line Search and Replace

Learn search and replace in Perl.
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Category: Help & How To

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Ivory Tower

We learned in the last episode that "Regular Expressions" or "RegEx" is just another way of saying, "find a pattern"

We learned that we can use RegEx to search a string for that pattern according to a set of parameters and modifiers that WE determine

The usage of RegEx is as Follows:

$nameofstring =~ (Match Operator) / (expression) / (expression) / (Match Expression Operator)

Which means:

$nameofstring =~ (action to take)/(pattern to match)/(pattern to replace match with)/(how to search)

Useful Match Operators

  • m/ Match Regular Expression
  • s/ Substitite Regular Expression
  • tr/ Tranliterate Regular expression

Useful Match Operator Modifiers

  • g Match globally, find ALL occurences
  • i case insensitive
  • m treat string as multiple lines
  • o Evaluate the expression only once
  • s treat string as single line
  • x Use extended regular expressions (Allows you to use white space in the expression)

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