The operators used in MPW expressions are organized in functional groups in the list below.
The groups are listed in decreasing order of precedence; operators within groups have the same precedence.
Table A-1: MPW Operators
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Grouping
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(expr)
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Groups expressions; overrides operator precedence
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Negation
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-
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Unary negation
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~
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Bitwise negation
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!
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NOT
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¬ (Option-l)
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Logical NOT †
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Multiplication and Division
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*
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Multiplication
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÷ (Option-/)
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DIV
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Division
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%
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MOD
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Modulus division
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Addition and Subtraction
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+
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Addition
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-
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Subtraction
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Shift
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<<
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Shift left
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>>
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Shift right
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Relational
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<
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Less than
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<=
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≤ (Option-<)
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Less than or equal to
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>
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Greater than
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>=
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≥ (Option->)
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Greater than or equal to
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String
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==
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Equal
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!=
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<>
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≠ (Option-=)
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Not equal
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=~
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Equal--regular expression ‡
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!~
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Not equal--regular expression ‡
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AND and OR
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(Operators within this group are listed in decreasing order of precedence.)
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&
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Bitwise AND
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^ (Option-I)
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Bitwise XOR
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Bitwise OR
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&&
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AND
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Logical AND †
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||
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OR
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Logical OR †
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† The !, NOT, ¬, &&, AND, ||, and OR logical operators interpret null and zero operands as false and nonzero operands as true. Relational operators function in a similar manner, returning 0 when the relation is true, and 1 when it is false.
‡ The =~ and !~ pattern-matching operators match a regular expression right operand (enclosed in the delimiters /…/) with a left operand.
Note that when evaluating an expression that uses a regular expression with the tagging operator ®,
the MPW Shell creates variables of the form {®n}, containing the matched substrings for each ® operator.
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Copyright Apple Computer, Inc. 1993-2000
Last Updated July 2000
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