literal string

[StephenGerads]

Where can I find how to put a literal string into an expression? When I search for TestStand string literal, I find nothing.

Thanks.

[crossrulz]

I'm not totally sure what you mean by literal string, but I'm thinking you just need to put quotes around your string.

[StephenGerads]

By literal string, I mean don't unescape any slash codes.

[crossrulz]

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@StephenGerads wrote:

By literal string, I mean don't unescape any slash codes.

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Ah.  Yeah, I've had that problem as well.  I ended up just using the double slash (\\) whenever I had a slash in my string.  I hope there's a better solution.

[StephenGerads]

I know there is a way to do it in the newer TS versions. I wish details were easy to locate with search "TestStand literal string".

[dug9000]

You can either use double back-slashes (to escape the backslashes themselves), or, in TestStand 2012 and higher, you can use the @ symbol before the string literal to avoid the unescaping. For example:

@"my string w\ith\ backslashes"

The following is from the expression browser help in the "Operators/Functions" tab under Constants->Other:

"Add an '@' before the enclosed quotes to turn a string constant into an unescaped string constant. Unlike for regular string constants, backslashes are left as is instead of specifying an escape sequence. Use "" for " within an unescaped string constant."

Hope this helps,

-Doug

[Al.B]

Alternatively, you can use the RunState.Engine.Utility.Escape() method to emulate the behavior of the "@" symbol in TestStand 2010 SP1 and earlier:

RunState.Engine.Utility.Escape("\test",0)

[StephenGerads]

Al B,

Can you arrange to have it easy to find this information in help?

Thanks.

Steve

[Al.B]

Hi Steve,

For future TestStand versions, we would recommend using the "@" approach as mentioned by dug9000, so there are no plans to further document the escape method I mentioned.  However, you can find information on expression operators and functions in the TestStand help (Expression Functions and Expression Operators topics) or in the description field within the expression browser. 

[Al.B]

Hi, I did a bit more testing with the utility.escape method I suggested, and it doesn't behave exactly in the same way as the "@" operator like I originally stated.  The difference is in the case when a backslash is not forming a special character.  In this case, the unescape method adds an additional backslash, for example:

• @"C:\windows\test" - will return "C:\windows\test"
• RunState.Engine.Utility.Escape("C:\windows\test",0) - will return "C:\\windows\test"

Both of these results will work with a file open operation, but I would suggest using the "\\" method with TestStand 2010 or earlier rather than the unescape method just to be sure you are not getting unexpected double backslashes.