Library: GNU bash Command Reference (Darwin 9.0): open-bracket open-bracket

Library: GNU bash Command Reference (Darwin 9.0)

open-bracket open-bracket

[[ ... ]]: [[ expression ]]

Returns a status of 0 or 1 depending on the evaluation of the conditional
expression EXPRESSION.  Expressions are composed of the same primaries used
by the `test' builtin, and may be combined using the following operators

( EXPRESSION )	Returns the value of EXPRESSION
! EXPRESSION	True if EXPRESSION is false; else false
EXPR1 && EXPR2	True if both EXPR1 and EXPR2 are true; else false
EXPR1 || EXPR2	True if either EXPR1 or EXPR2 is true; else false

When the `==' and `!=' operators are used, the string to the right of the
operator is used as a pattern and pattern matching is performed.  The
&& and || operators do not evaluate EXPR2 if EXPR1 is sufficient to
determine the expression's value.

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