how to find the higher java version on linux machine with bash or shell script

Question

we need to test and compare java versions

any suggestion for tricky way how to verify if $version > $New_version ?

[root@master tmp]# version=$(java -version 2>&1 | awk -F '"' '/version/ {print $2}') [root@master tmp]# echo $version 1.8.0_65 [root@master tmp]# New_version=1.8.0_111 [root@master tmp]# [[ $version > $New_version ]] && echo ok ok [root@master tmp]# 

Answer 1

Use GNU sort's version-sort along with the "check if input is sorted" option:

printf '%s\n%s\n' "$version" "$New_version" | sort -rVc 2>/dev/null && echo ok 

The 2>/dev/null is to drop sort's complaint when the input is not sorted; you just want to know if it's sorted or not, which is reflected in the return code.

Sample run:

$ version=1.8.0_65 $ New_version=1.8.0_111 $ printf '%s\n%s\n' "$version" "$New_version" | sort -rVc 2>/dev/null && echo ok $ version=1.8.0_650 $ printf '%s\n%s\n' "$version" "$New_version" | sort -rVc 2>/dev/null && echo ok ok $ 

---

Alternatively, do it the hard way:

oldstr=${old//./ } oldstr=${oldstr//_/ } newstr=${new//./ } newstr=${newstr//_/ } read -a oldarr <<< "$oldstr" read -a newarr <<< "$newstr" [ ${oldarr[0]} -ge ${newarr[0]} ] && [ ${oldarr[1]} -ge ${newarr[1]} ] && [ ${oldarr[2]} -ge ${newarr[2]} ] && [ ${oldarr[3]} -gt ${newarr[3]} ] && echo OK 

This sets up new variables where we replace all of the dots and underscores with spaces, then feed those as here-strings into read to split them into arrays, then we compare each element of the parallel arrays.