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5.6. Expressions

SystemTap supports a number of operators that use the same general syntax, semantics, and precedence as in C and awk. Arithmetic is performed per C rules for signed integers. If the parser detects division by zero or an overflow, it generates an error. The following subsections list these operators.

5.6.1. Binary numeric operators
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* / % + - > > < < & | && ||

5.6.2. Binary string operators
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. (string concatenation)

5.6.3. Numeric assignment operators
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= *= /= %= += -= > >= < <= &= = |=

5.6.4. String assignment operators
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= .=

5.6.5. Unary numeric operators
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+ - ! ~ ++ --
< > <= >= == !=

5.6.7. Ternary operator
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cond ? exp1 : exp2

5.6.8. Grouping operator
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( exp )

5.6.9. Function call
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General syntax:
fn ([ arg1, arg2, ... ])

5.6.10. $ptr->member
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ptr is a kernel pointer available in a probed context.

5.6.11.  in
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This expression evaluates to true if the array contains an element with the specified index.

5.6.12. [ , … ] in
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The number of index values must match the number of indexes previously specified.
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