[paulo@cambridge ~] $ which gs
/usr/bin/gs
[paulo@cambridge ~] $ file `which gs`
/usr/bin/gs: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=ff74aabc42bd98319293ba7270b1fe904b58c1ea, stripped
[paulo@cambridge ~] $ gs --version
9.15