[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Extended pattern matching operators and the =~ operator

From: M. Nejat AYDIN
Subject: Extended pattern matching operators and the =~ operator
Date: Thu, 2 Jul 2020 05:01:49 +0300
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0

An example given in the Bash Reference Manual, section
Conditional Constructs, seems to imply that extended pattern matching
operators can be used in the string to the right of the '=~' operator,
which is suspicious to me. Quoting from the manual:

  For example, the following will match a line (stored in the shell
  variable line) if there is a sequence of characters in the value
  consisting of any number, including zero, of space characters, zero or
  one instances of ‘a’, then a ‘b’:
    [[ $line =~ [[:space:]]*?(a)b ]]
  That means values like ‘aab’ and ‘ aaaaaab’ will match, as will a line
  containing a ‘b’ anywhere in its value.

Please notice the use of "?(a)" extended pattern matching expression.
Is it an error in the manual, or did I overlook something?

reply via email to

[Prev in Thread] Current Thread [Next in Thread]