bash_scripting
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Bash Scripting
- Maths
- Colours]]
- highlighting - Page not found.
bc
You can use bc in bash to do maths calculations with decimals. The man pages can be found:
http://unixhelp.ed.ac.uk/CGI/man-cgi?bc+1
Example Calulation
bc -l <<< "20 / ( 20 + 80) * 100 "The output looks like:
20.00000000000000000000
-l = --mathlib = Defines the standard math library
Limiting the decimal place
You can then use this with printf to limit the number of decimals shown: \\The example below shows the results to 3 decimal places. You can replace the 3 with what ever value you wish to place
printf "%.3f\n" $(bc -l <<< "20 / ( 20 + 80) * 100 ")
You can also use bc with variables:
bc -l <<< "($used / ( $free + $used) ) * 100 ")
Comparing Decimals with bc
You are able to compare decimal numbers using bc. The output will return 1 or 0 depending on the results. You can then use this with an if statment -le / -ge etc
1.4 '<' 1.3 | bc -l
example= $(echo 1.4 '<' 1.3 | bc -l) if [ $example-eq 0 ]; then elif [ $example-eq 1 ]; then fi
bash_scripting.1431212125.txt.gz · Last modified: 2024/05/23 07:26 (external edit)