Introduction
In several parts of Horde, you can specify a query condition to select particular agents for an operation. These condition strings are stored in JSON configuration flies as a string and have a C-like syntax.
Agents report many properties collected from their characteristics, which you can view from the Agents page on the Horde dashboard. Agents may report multiple values for a particular key, such as PlatformGroup: Desktop and PlatformGroup: Unix. Conditions evaluate to true if there is any value for a particular key that satisfies the expression.
Values
Values in condition strings are dynamically typed and coerced into the correct format for the operation performed on them. For example, the integer 0, the strings '0' and 'false', and the boolean false are functionally equivalent.
Integers can be given the following binary order-of-magnitude suffixes as a shorthand:
| Suffix | Size |
|---|---|
| Kb | 2^10 (1,024) |
| Mb | 2^20 (1,048,576) |
| Gb | 2^30 (1,073,741,824) |
| Tb | 2^40 (1,099,511,627,776) |
Operators
Operators follow standard C rules of precedence. Sub-expressions may be enclosed in ( parentheses ).
Boolean Operators
| Operator | Description |
|---|---|
true |
Boolean literal |
false |
Boolean literal |
!A |
Negation |
A && B |
Logical AND |
A \|\| B |
Logical OR |
A == B |
Equality |
A != B |
Inequality |
Integer Operators
| Operator | Description |
|---|---|
1234 |
Integer literal |
1234kb |
Integer literal with binary size suffix (evaluates to 1,263,616). |
A == B |
Test for equality |
A != B |
Test for inequality |
A < B |
Test if one value is less than another |
A <= B |
Test if one value is less than or equal to another |
A > B |
Test if one value is greater than another |
A >= B |
Test if one value is greater than or equal to another |
A == B |
Test for equality |
String Operators
| Operator | Description |
|---|---|
'value' |
String literal |
"value" |
String literal |
A == B |
Test if two strings compare equal for equality. Comparison is case-insensitive. |
A != B |
Test if two strings are different. Comparison is case-insensitive. |
A ~= B |
Test if a string (A) matches a regex (B). The regex comparison is case-insensitive. |