expr - Evaluate arguments as an expression
Synopsis
expr operand ...
Description
The expr utility evaluates an expression formed by the operands and writes the result to standard output.
Operands
The format of the expression to evaluate is shown as follows. expr, expr1, and expr2 can be decimal integers or strings.
Note:
|
The six relational expressions return the result of a decimal integer comparison if both arguments are integers. Otherwise, they return the result of a string comparison. The result of each comparison is 1 if the specified relationship is true, or 0 if the relationship is false. |
| Expression | Description |
|---|---|
| expr1 | expr2 | Returns the evaluation of expr1 if it is neither null nor zero; otherwise, returns the evaluation of expr2. |
| expr1 & expr2 | Returns the evaluation of expr1 if neither expression evaluates to null or zero; otherwise, returns zero. |
| expr1 = expr2 | Equal. |
| expr1 > expr2 | Greater than. |
| expr1 >= expr2 | Greater than or equal. |
| expr1 < expr2 | Less than. |
| expr1 <= expr2 | Less than or equal. |
| expr1 != expr2 | Not equal. |
| expr1 + expr2 | Addition of decimal integers. |
| expr1 - expr2 | Subtraction of decimal integers. |
| expr1 * expr2 | Multiplication of decimal integers. |
| expr1 / expr2 | Division of decimal integers. |
| expr1 % expr2 | Remainder of decimal integer division. |
| expr1 : expr2 | Matching expression. |
| ( expr ) | Grouping symbols. |
Exit status
- 0 when the expression evaluates to neither null nor zero.
- 1 when the expression evaluates to null or zero.
- 2 when the expression is invalid.
- >2 when an error occurred.
Examples