BASH rounding float to the nearest tenth

Question

How do you round floats to the nearest tenths using bc. I have a variable called loadMin

loadMin=$(uptime | cut -d" " -f14 | cut -c 1-4)

which returns the load averages per minute with two decimal places. I.e 0.01 0.02 0.09. I need the number to be rounded to the nearest tenth. For example 0.01 rounded to 0.0 or 1.09 rounded to 1.1

Any help is appreciated.

Did you see http://stackoverflow.com/questions/2394988 ? – dimir Nov 26 '12 at 20:13 — dimir, Nov 26 '12 at 20:13

gniourf_gniourf · Accepted Answer · 2012-11-26T20:21:00.397

8

Why use bc? printf will happily do that:

printf "%.1f" "$loadMin"

If you need to put the result in a variable:

printf -v variable "%.1f" "$loadMin"

edited Nov 26 '12 at 20:21

answered Nov 26 '12 at 20:15

gniourf_gniourf

44,650
9
93
104

Thanks! I ended up using the latter; printf -v variable "%.1f" "$loadMin". It successfully rounded these numbers to the nearest tenth: 2.09 to 2.1--- 0.09 to 0.1--- 2.99 to 3.0 – Francis Batalla Nov 26 '12 at 21:02

score 1 · Answer 2 · answered Nov 26 '12 at 20:15

You can do this in one go with awk:

loadMin=$(uptime | awk '{printf "%0.1f", $14}')

Explanation:

Instead of using cut, use awk instead to make these easier
awk delimit on spaces and tabs by default and separates each line into fields.
'{printf "%0.1f", $14}': print the 14th field as a floating number, rounded to the nearest 1 decimal place.

BASH rounding float to the nearest tenth

2 Answers2