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Tutorial12: Shell Scripting - Part 2

12 bytes added, 10:55, 21 March 2021

→‎INVESTIGATION 2: ADDITIONAL LOOPING STATEMENTS

# Save your editing session and exit the text editor (eg. with vi: press '''ESC''', then type ''':x''' followed by '''ENTER''').

# Set execute permissions for this shell script and run your shell script by issuing: ./for-6.bash '''You should have noticed an error message'''.

# To demonstrate what went wrong, issue the following '''commands''': num1=5;num2=10 result=$num1+$num2 echo $result Notice that the user-defined variable stores the text "'''10+5'''" which is NOT the expected result of adding the number '''10 ''' and '''5'''. As you may recall in '''tutorial 10''', we need to convert a number stored as text into a '''binary number''' for calculations (in this case, advance the value by 1 for each loop). We can accomplish this by using the math construct '''(( ))'''

# To demonstrate, issue the following set of '''commands''': num1=5;num2=10 sum=$(($num1+$num2)) echo $sum ((product=$num1*$num2)) echo $product Let's correct our '''for-6.bash''' shell script to correctly use math operations.

# Use a text editor like vi or nano to edit the text file called '''for-6.bash''' (eg. vi for-6.bash)

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Tutorial12: Shell Scripting - Part 2

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