What is the special character / escape for "whitespace" in a POSIX extented regular expression?

Question

I am new to this regular exp concept. I am trying to use this reg ex

[^@\s]+$

If i give the string as "abs", its actulally excluding the character 's' . which means '\s' is read as a character 's' rather than a whitespace. Please help me to solve this problem

Please check if my edit is correct. I don't know if `.` is part of your regex, but I think it is likely not, so I removed it. — nhahtdh, Oct 16 '14 at 05:43

score 5 · Accepted Answer · answered Oct 16 '14 at 05:46

5

You can use this POSIX equivalent:

^[^@[:space:]]+$

[:space:] matches any whitespace including newline. If you want to avoid matching newlines then use: [:blank:] instead.

answered Oct 16 '14 at 05:46

anubhava

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Hi anubhava. does POSIX support unicode regular expression? – user3913114 Oct 17 '14 at 07:08
I believe it is not supported in POSIX, pls check here: http://www.regular-expressions.info/posixbrackets.html – anubhava Oct 17 '14 at 07:10

score 5 · Answer 2 · answered Oct 16 '14 at 05:47

5

The space character class in POSIX is [:space:], so in your case, your regex would be:

[^@[:space:]]+$

Note that [:space:] can't standalone outside [] like \d or \s in other flavors. A space character class alone must be inside []:

[[:space:]]

answered Oct 16 '14 at 05:47

nhahtdh

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What is the special character / escape for "whitespace" in a POSIX extented regular expression?

2 Answers2