Shell scripting - Comparing floating number within if then else

Question

I need to make a comparison between floating numbers within the if. For example,

if [1.1 -gt .45] && [1.1 -lt 2.9]

Then
...

fi

In the case of my program I've tried ...

if [ "$ {restogpsweek [0]} -gt 0.1"] && [ "$ {restogpsweek [0]} -lt 2.2"]

if [ "$ {restogpsweek [0]} -gt 0.1" | bc] && [ "$ {restogpsweek [0]} -lt 2.2" | bc]

if [`echo" $ {restogpsweek [0]} -gt 0.1 "| bc`] && [ `echo" $ {restogpsweek [0]} -lt 2.2 "| bc`]

and "n" other things and not found ...

Does anyone know how to do these comparisons?

Hugs

score 1 · Accepted Answer · answered Jun 28 '16 at 04:13

1

bash can not do floating point arithmetics.

You can use a more advanced shell like zsh:

% [[ 1.1 -gt .45 ]] && echo 'Ok'
Ok

Or use bc to do the comparison:

$ echo '1.1 > .45' | bc -l
1

bc returns 1 if true and 0 if false.

answered Jun 28 '16 at 04:13

heemayl

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So, I only can use `bash` with floating point if it is a calculus.. to compare I need to change to the another shell like `zsh`, is it? Thanks a lot.. – Rodrigo Mendes da Rocha Jun 28 '16 at 04:18
@RodrigoMendesdaRocha In bash, you need to take help of `bc` – heemayl Jun 28 '16 at 04:26
to do some calculus i use, but, comparing within it, `bc` doesn't work – Rodrigo Mendes da Rocha Jun 28 '16 at 04:28

Shell scripting - Comparing floating number within if then else

1 Answers1