Constants

PGL supports constants of several types.

1. Boolean constants

Supported boolean constants are: no, false, off, yes, true, and on.

2. Numbers

Integer and floating point constants are supported. An integer constant is simply a sequence of digits. A floating point number is two sequences of digits separated by a period. Exponential notation for floating point numbers is also supported.

17
1.23
1e34
1.20e-12

A handy ``percent'' representation is also available: appending an & sign to a number is the same as dividing that number by 100. The following constants are equal.

30%
0.30
0.3

3. Strings

String constants are formed by double-quoting text.

"string"
"this is a string"

4. Time constants

Time constants are numbers immediately followed by time ``scale'' tags. Recognized tags are msec, sec, min, hour, day, and year. The number part is optional and defaults to 1. If the number part is present, the ms, s, and hr tags can also be used, but do not do that. The following constants are equal.

min
1min
60sec

5. Size constants

Size constants are numbers immediately followed by size ``scale'' tags. Recognized tags are Byte, Kb, KB, MB, Mb, Gb, and GB. The number part is optional and defaults to 1. The following constants are equal.

KB
1KB
8Kb
1024Byte

6. Network addresses

Network addresses are formed by surrounding an address with single quotes. Details like network interface name, port number, and subnet can be used where appropriate.

'10.0.0.1'
'10.0.0.1:80'
'fxp0::10.0.0.1:80'
'fxp0::10.0.0.0:80/16'
'www.host1.com'
'www.host2.com:8080'

Address ranges (i.e., address array constants) are also supported.

'10.0.1-4.1-250'
'10.0.1-4.17/24'
'www.host[1-4].com:80'