Version of Bash
The version information can be found in the following shell variable
Expands to a string describing the version of this instance of bash.
echo ${BASH_VERSION}
4.3.46(1)-release
A readonly array variable whose members hold version information for this instance of bash. The values assigned to the array members are as follows:
Example
echo ${BASH_VERSINFO[0]}
4
echo ${BASH_VERSINFO[1]}
3
echo ${BASH_VERSINFO[2]}
46
echo ${BASH_VERSINFO[3]}
1
echo ${BASH_VERSINFO[4]}
release
echo ${BASH_VERSINFO[5]}
x86_64-pc-linux-gnu