Shell Regular Expression

Classification of regular expressions

1. Basic Regular Expressions (basic Regular expression also known as basic RegEx abbreviation Bres)

2. Extended Regular expression (Extended Regular expression also known as Extended RegEx abbreviation Eres)

3. Perl Regular Expressions (Perl Regular expression called Perl RegEx abbreviation pres)

Basic components

The basic component of a regular expression.

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POSIX character class

The POSIX character class is a special meta-sequence (meta sequence) of a shape such as [: ...:] that can be used to match a specific range of characters.

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Metacharacters

Metacharacters (meta character) is a Perl-style regular expression that is supported by only a subset of text processing tools, not all text processing tools.

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Shell Regular Expression