Get the value before decimal point

Question

I am writing a Bash script. I have a variable in it which is a float value. For example:

x=2099.2

I need the value before decimal point, i.e, only 2099.

Answer 1

You can use the following shell parameter expansion:

${x%%.*}

This removes everything from the first dot.

See it live:

$ v=203.4
$ echo ${v%%.*}
203

$ v=2.3.4
$ echo ${v%%.*}
2

From Bash Reference Manual → 3.5.3 Shell Parameter Expansion:

${parameter%%word}

The word is expanded to produce a pattern just as in filename expansion. If the pattern matches a trailing portion of the expanded value of parameter, then the result of the expansion is the value of parameter with the longest matching pattern deleted. If parameter is ‘@’ or ‘’, the pattern removal operation is applied to each positional parameter in turn, and the expansion is the resultant list. If parameter is an array variable subscripted with ‘@’ or ‘’, the pattern removal operation is applied to each member of the array in turn, and the expansion is the resultant list.