Conditions
Branch a script with IF / ELSE_IF / ELSE / IF_END and string or numeric comparators
Sur cette page
IF runs the commands up to its matching IF_END only when a condition is true. Conditions compare two quoted operands with a comparator between them.
Syntax
IF "<a>" <comparator> "<b>"
<commands>
IF_END- Both operands must be quoted.
- The comparator is detected only between the two operands, so operand text containing
is,!=,<and so on is never mistaken for the operator. - If no valid comparator is found (or a numeric comparator gets non-numeric operands), the condition is treated as false.
IF "admin" is "admin"
writeLn "Access granted"
IF_ENDOperands are expanded
_@ state values resolve to lowercase when expanded through ${…}$ (for example windows, on, off), so always compare against a lowercase literal.
_$VAR os = "_@detectedOS"
IF "${os}$" is "windows"
terminal 'windows' powershell
IF_ENDComparators
String comparators work on any value. The numeric comparators only evaluate when both operands parse fully as numbers; otherwise the condition is false.
| Comparator | Alias | Type | True when |
|---|---|---|---|
is | == | string | Operands are exactly equal (case- and space-sensitive) |
is not | != | string | Operands are not equal |
< | numeric | a is less than b | |
> | numeric | a is greater than b | |
<= | numeric | a is less than or equal to b | |
>= | numeric | a is greater than or equal to b |
IF "5" < "10"
writeLn "5 is less than 10"
IF_ENDELSE_IF and ELSE
IF blocks support ELSE_IF <cond> and ELSE branches and can be nested. Exactly one branch runs — the first whose condition is true.
_$VAR os = "_@detectedOS"
IF "${os}$" is "windows"
terminal 'windows' powershell
ELSE_IF "${os}$" is "macos"
terminal 'mac'
ELSE
terminal 'linux'
IF_END