List supported SSL/TLS versions for a specific OpenSSL build

You can not check for version support via command line. Best option would be checking OpenSSL changelog.

Openssl versions till 1.0.0h supports SSLv2, SSLv3 and TLSv1.0. From Openssl 1.0.1 onward support for TLSv1.1 and TLSv1.2 is added.

It's clumsy, but you can get this from the usage messages for s_client or s_server, which are #ifed at compile time to match the supported protocol versions. Use something like

 openssl s_client -help 2>&1 | awk '/-ssl[0-9]|-tls[0-9]/{print $1}' 
 # in older releases any unknown -option will work; in 1.1.0 must be exactly -help

Use this

openssl ciphers -v | awk '{print $2}' | sort | uniq

This worked for me:

openssl s_client -help 2>&1  > /dev/null | egrep "\-(ssl|tls)[^a-z]"

Please let me know if this is wrong.