Hi, have experienced the following:
3.1.17(1)-release: -> [[ a =~ a|b ]] && echo true -bash: syntax error in conditional expression: unexpected token `|' -> [[ a =~ a\|b ]] && echo true # that one works in version 3 true =================================================================== 4.1.10(4)-release: -> [[ a =~ a\|b ]] && echo true # ... but not in version 4 -> [[ a =~ a|b ]] && echo true true Do I really need to check BASH_VERSION first? Thanks & regards, Peter