Sed Regular Expressions: Difference between revisions
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Use <tt>\(</tt> and <tt>\)</tt> for grouping. Parentheses must be escaped to be interpreted as grouping separator. | Use <tt>\(</tt> and <tt>\)</tt> for grouping. Parentheses must be escaped to be interpreted as grouping separator. | ||
=Negation= | |||
Match everything except the specified characters: | |||
<syntaxhighlight lang='text'> | |||
[!abc] | |||
</syntaxhighlight> | |||
=Examples= | =Examples= |
Revision as of 04:33, 5 January 2021
Internal
Meta-Characters - Special Characters (need to be escaped in regular expressions)
/ " $ # unescaped signifies end of line ^ # unescaped signifies the beginning of a line ! [ ] : * # zero or more . # dot
Single quote is a special case, to match it use its ASCII hexadecimal value prefixed by \x as follows, instead of escaping it:
\x27
To use () for grouping, they need to be escaped:
\(...\)
More details in Grouping below.
Non-Special Characters (do not need to be escaped in regular expressions)
< > ( ) ! - { } + # this is interesting, I thought '+' is a meta-character, more experimentation necessary.
Grouping
Use \( and \) for grouping. Parentheses must be escaped to be interpreted as grouping separator.
Negation
Match everything except the specified characters:
[!abc]
Examples
Match everything except space:
[^ ]*
.*
seems to work too.
Words (digits, alpha, _):
sed -e 's/[0-9a-zA-Z_]*/THIS_WAS_A_WORD/g'
Blank spaces (spaces, tabs, newlines): \s does not seem to work.
Regular Expression Syntax
TO NORMALIZE across java Regular Expression Syntax, grep Regular Expression Syntax, sed Regular Expression Syntax.