On Thu, Sep 29, 2011 at 11:18:57AM -0500, Peng Yu wrote: > Also, regex(3) does not mention the difference between $x =~ xxxx.txt > and $x=~ "xxxx.txt". I think that the difference should be addressed > in man bash.
It already is. An additional binary operator, =~, is available, with the same precedence as == and !=. When it is used, the string to the right of the operator is considered an extended regular expression and matched accordingly (as in regex(3)). The return value is 0 if the string matches the pattern, and 1 otherwise. If the regular expression is syntactically incorrect, the conditional expression's return value is 2. If the shell option nocasematch is enabled, the match is performed without regard to the case of alphabetic characters. Any part of the pattern may be quoted to force it to be matched as a string. The last sentence in the quote above. > Bottom line, regex(3) is not a good manpage to refer in the above > sentence. Maybe it's not a good one, but it is the only *possible* one.