Question

The purpose of my code is

• To read two values from two separate files. [Working perfectly well]
• To convert them into decimal values. [Working fine]
• Find their differences. [Working fine]
• To make the difference positive if it is a negative value. [Not Working, it’s not checking the condition.]

Here is my code. Its coded in Ubuntu 11.04.

...
while read line;
do
echo -e "$line";
AllOn=$line
done<Output.log

gcc -Wall -o0 Test.c -o output
time -f "%e" -o BaseFile.log ./output
while read line;
do
echo -e "$line";
AllOff=$line
done<BaseFile.log

#Threshold Value
Threshold=`echo "$AllOff - $AllOn" | bc`;
echo "Threshold is $Threshold"
if [ `echo "$Threshold < 0.00"|bc` ]; then
   Threshold=`echo "$Threshold * -1" | bc`;
fi
echo "\nThreshold is $Threshold" >> $Result

Now, irrespective of the value, the if clause is getting executed. I think, my if condition is not being checked and that it would be the reason for the following output.

Base Time is 2.94
All Techniques Off = 3.09
Threshold is .15


Base Time is 3.07
All Techniques Off = 2.96
Threshold is -.11

UPDATE: This question is not answered completely yet and if any one could suggest me a way to achive my 4th objective of finding the difference between the values, it would be really helpful for me. Thank you.

Answer 1

What shell are you using? I’m assuming just plain old ‘sh’ or ‘bash’.

If so, look at line 33 where you have:

if($Threshhold<0) then

Switch that to:

if [ $Threshhold -lt 0 ]; then

You might have other issues, I haven’t looked through the code closely to check for them.

To further expand, I knocked up test script and data (please note I changed ‘Threshhold’ to ‘Threshold’):

# Example test.sh file
!/bin/bash

while read line;
do
echo "$line";
AllOn=$line
done < Output.log

while read line;
do
echo "$line";
AllOff=$line
done < BaseFile.log

#Threshhold Value
Threshold=`echo "$AllOn - $AllOff" | bc`;
echo "Threshold is $Threshold"
if [ `echo "$Threshold < 0"|bc` ]; then
  # snips off the '-' sign which is what you were trying to do it looks
  Threshold=${Threshold:1}
fi
echo $Threshold
Result=result.txt
echo "\nThreshold is $Threshold" >> $Result

Then some data files, first Output.log:

# Output.log
1.2

Then BaseFile.log:

# BaseFile.log
1.3

Example output from the above:

./test.sh
1.2
1.3
Threshold is -.1
.1