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# 1  
Old 07-22-2009
String Arithmetic ?

Hello Experts,

In my shell I need to perform some simple subtraction on a value returned as a result of the "wc" command. The code:

Code:
scanFromLine="100"  ## This is returned as string as a result of some operation

totalLines=`wc -l "${latestLogFile}" | awk '{print $1}'` ## eg: 200

scanFromLine=`$(( ${totalLines} - ${scanFromLine} ))` ## this line throws an error

The error that I get is:
Code:
h1[227]: 200:  not found.

I am very positive that the error is not thrown because of the values being string. Please tell me my mistake here.

Regards,
HKansal
# 2  
Old 07-22-2009
Remove the backticks (`) from this line:

Code:
scanFromLine=`$(( ${totalLines} - ${scanFromLine} ))` ## this line throws an error

Regards
# 3  
Old 07-22-2009
Damn!

I can only be sorry I did that to myself. So careless.

Thank you Franklin.

Regards,
HKansal
 

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