floating-point operations with bash

string bash replace exif operation
quickbug picture quickbug · Dec 21, 2013 · Viewed 13.6k times · Source

how can I transform the string "620/100" into "6.2" in a bash script

The context of my question is about image processing. EXIF data are coding the focal length in fractional format, while I need the corresponding decimal string.

Thanks for helping, Olivier

Answer

anubhava picture anubhava · Dec 21, 2013

Use bc -l

bc -l <<< "scale=2; 620/100"
6.20

OR awk:

awk 'BEGIN{printf "%.2f\n", (620/100)}'
6.20

Related questions

Replace one character with another in Bash

I need to be able to do is replace a space () with a dot (.) in a string in bash. I think this would be pretty simple, but I'm new so I can't figure out how to modify a similar example …

Read More
How to check if a string contains a substring in Bash

I have a string in Bash: string="My string" How can I test if it contains another string? if [ $string ?? 'foo' ]; then echo "It's there!" fi Where ?? is my unknown operator. Do I use echo and grep? if echo "$string" | …

Read More
Extract filename and extension in Bash

I want to get the filename (without extension) and the extension separately. The best solution I found so far is: NAME=`echo "$FILE" | cut -d'.' -f1` EXTENSION=`echo "$FILE" | cut -d'.' -f2` This is wrong because it doesn't …

Read More