Switch Statement and variables

[Nate Kruse]

Ran into another problem.  Is there a way to use a switch statement and have it look at the value of a variable for the comparison?  In the following switch statement, the switch doesn’t recognize or match with $SegOne.  Even though I get SegmentType as MSH, it never hits the SegOne case.  I don’t want to hardcode MSH in the switch as that would defeat the purpose of using a variable.

Any thoughts?  I’d appreciate it.

Thanks,

Nate.

set SegOne MSH

set SegmentType [lindex $seg 0]

switch -exact — $SegmentType {

  $SegOne {

    puts stdout “Inside with $SegOne”

  }

  default {

    puts stdout “Outside with $SegmentType”

  }

}

Topic

[Max Drown (Infor)]

No. I don’t believe that’s possible. Here’s a demo based on your code.

Code:

set seg [list MSH EVN PID PV1 ORC OBR OBX]
set SegOne MSH

#set SegmentType [lindex $seg 0]
set SegmentType {$SegOne}

switch -exact — $SegmentType {
 $SegOne {
   puts stdout “Inside with $SegOne”
 }

 default {
   puts stdout “Outside with $SegmentType”
 }
}

The switch sees “$SegOne” as a literal string, not a variable name.

-- Max Drown (Infor)

[Max Drown (Infor)]

What exactly are you trying to do? Maybe we can come up with an appropriate work around.

-- Max Drown (Infor)

[Nate Kruse]

I’m trying to create a tcl script that will be reusable in the future with minimal modifications.  I want to have a “bank” of variables at the top of the script.  The user can then open the script, change a few variables from the “bank” with fields they want to output (such as MSH or PID or anything) and then run the script against a file.  Not every person who runs the script will want the same field values extracted, so hardcoding values isn’t the way I want to go.

I could go with If statements, but was hoping the switch would work.

[Steve Carter]

Based on what you stated you wanted to do with the message, you could do this:

set SegList “MSH PID”

set SegmentType [lindex $seg 0]

if { [lcontain $SegList $SegmentType] } {

[Nate Kruse]

Steve Carter wrote:

Based on what you stated you wanted to do with the message, you could do this:

set SegList “MSH PID”

set SegmentType [lindex $seg 0]

if { [lcontain $SegList $SegmentType] } {

[Nate Kruse]

Thanks for all the replies and your time.  I tried a few things, but this one by Graham Ellis at opentalk worked best.  I’m still able to use the switch statement.

http://www.wellho.net/cgi-bin/opentalk/YaBB.pl?board=tcl;action=display;num=1184944258;start=0

[Max Drown (Infor)]

Could you post the final code block, please?

-- Max Drown (Infor)

[Nate Kruse]

Max Drown wrote:

Could you post the final code block, please?

Sure, here is the switch part…

switch -exact — $SegmentType “

  $SegOne {

     puts stdout “Inside with $SegOne”

  }

  default {

     puts stdout “Outside with $SegmentType”

  }

“

[Author]

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