==

Equal to

!=

Not equal to

>=

Greater than or equal to

<=

Less than or equal to

> 

Greater than

< 

Less than

.head.

Whether sting1 (left) begin with string2(left)  (case insensitive)

.isOneof.

Whether string1 is one of string2, which is a list (case insensitive)

   Example: if($day .isoneof. “Monday Tuesday Sunday”) ...

-f <filename>

Whether file exists or not

-d <folder name>

Whether directory exists or not

-var <variable name>

Whether variable declared or not

-z <string>

Whether the string is empty

-os <os type>

To test which OS runs on, available are MSW, Linux, MacOSX,

This is used to test first before call a external system utilityes

For example to remove a batch of files by calling system utilities

If(-os msw) exec del *.out

Else  exec rm –rf *.out

!

Not