Extra x0d at end of message

It appears to me that the problem may be with the statement:

append newmsg $segr

That is inside the foreach loop and will append a “r” to each “seg” variable, INCLUDING the last seg.  I don’t think you would want to do this on the very last segment.

Try just getting the PID segment, grabbing the index, do your race code logic, then do an lreplace to place the new seg back into the “segments” list.   Then join your message back together then pass it on.   I’d take out the append altogether.  You could probably also do without the foreach by doing an lsearch in the “segments” list for ^PID.  Something like this would do the trick:

set pid_idx [lsearch -regexp $segments ^PID]

Hope this helps…

Tom Rioux

Because there’s a delimiter at the end of the message:

segsegseg

when split on CR this will result in

seg seg seg {}

For tcl procs that make changes to a segment, I’ve started adding this piece of code just before the msgset to get rid of the extra line feed at the end.

 # Get rid of double line feed at the end of the message.

 regsub -all {x0dx0d} $outBuff x0d outBuff

outBuff being whatever variable you use to save your message to before sending it on it’s way with msgset.

I’m sure I’m getting the extra line feed with “append outBuff ${segment}r” but if I take the r off, the proc always fails.  So I just started adding the regsub.

Is it normal to have a CR at the end of the last segment of an HL7 message?

Yes.  The HL7 standard refers to it as a “segment terminator”, not a “segment separator”.

That’s the way split works.

HL7 segments are terminated by a 13 (CR).  So, a simple illustration would be MSH(CR)PID(CR)PV1(CR)

When you split the message by the CR, you get a list containing MSH PID PV1 {} – that final null element is the result of the character you are splitting on being the last character of the data.  

If that null element did not exist, when you would join the segments back together, you would get MSH(CR)PID(CR)PV1, which would no longer be a properly formatted message.  Because the null element is the final list element, when joining the segments back together, the final CR is put back where it belongs.

If you were to have a improper message (just for illustration) of MSH(CR)PID(CR)PV1(CR)(CR) and split by CR, the resulting list would be MSH PID PV1 {} {}