Determine whether a CPU has 64 bit capability or not

if cat /proc/cpuinfo | grep " lm " &> /dev/null; then echo "Got 64bit" ; fi
Check if you have 64bit by looking for "lm" in cpuinfo. lm stands for "long mem". This can also be used without being root.

By: xeor
2010-04-10 15:31:58

1 Alternatives + Submit Alt

What Others Think

This is a bit cleaner and simpler: grep -q " lm " /proc/cpuinfo && echo "Got 64bit"
eightmillion · 643 weeks and 4 days ago
Just a nitpick: "lm" stands for long mode (not long mem), meaning that the processor registers are 64bit long in this mode. By the way, /proc/cpuinfo works on Linux only, of course, so this is not portable (except that it also works on FreeBSD when the "Linuxulator" is enabled and linprocfs mounted on /compat/linux/proc). On Solaris use this command to find out if 64bit is supported by the platform: isainfo -bv On FreeBSD, this command can be be used: grep -w "LM" /var/run/dmesg.boot && echo "Got 64bit"
inof · 643 weeks and 4 days ago
My two cents, for Red Hat flavours: arch sample output: x86_64
KoRoVaMiLK · 643 weeks and 2 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

You must be signed in to comment.

What's this? is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.


Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: