Echo calculation to text file

Question

I am working on a project to calculate my overtime at work with a shell script. I have two inputs and want to find if my number is over 800 = 8 hours; if it is bigger, then it has to print out the result to my text file. It has to print out my difference.

if [ $var1 -gt 800 ]; then
`expr $var1-800`
echo Overtime: "" >> $path

and then I'm lost because I don't how to print out the result of my calculation.

Gilles Quénot · Accepted Answer · 2018-02-22T16:28:14.720

1

Try this using modern bash (don't use backticks or expr) :

if ((var1 > 800)); then
    overtime=$((var1 - 800)) # variable assignation with the arithmetic 
    echo "Overtime: $overtime"
fi

Or simply :

if ((var1 > 800)); then
    overtime="Overtime: $((var1 - 800))" # concatenation of string + arithmetic
fi

Check bash arithmetic

edited Feb 22 '18 at 16:28

answered Feb 22 '18 at 13:39

Gilles Quénot

31,569
7
64
82

Hi, sorry think my explaining was wrong.. I type my checkin: 700 = 7:00 am then checkout: 1800 = 6:00pm Then I gotta find the difference from 1800-700 if over 800 it gotta print out the result – peter Feb 22 '18 at 13:53
1

And so ? Can't you just adapt the command ? You have all what you need. It's simple arithmetic. Doesn't this snippet get clear ? – Gilles Quénot Feb 22 '18 at 13:56
I'll try as I wrote im way to new to this... to make a project like this – peter Feb 22 '18 at 13:58
I do, im just new to programming with arithmetic and how its done in scripts – peter Feb 22 '18 at 14:00
Added comments in my snippet – Gilles Quénot Feb 22 '18 at 16:28

Kusalananda · Answer 2 · 2018-02-22T13:46:27.477

0

if (( var1 > 800 )); then
    printf 'Overtime: %d\n' "$(( var1 - 800 ))" >>"$path"
fi

expr and backticks are antiquated, and you don't even need a command substitution here.

edited Feb 22 '18 at 13:46

answered Feb 22 '18 at 13:39

Kusalananda

320,670
36
633
936

Echo calculation to text file

2 Answers2

Linked