If you've just upgraded your Linux box, or you are wondering how many processors a remote server has, there's a quick and dirty command you can use to display the number of processors. On Linux, /proc/cpuinfo contains all of the processor information for all current processors in your computer. This will include the speed, the amount of on-chip cache, processor type, and how many cores. Here's the command:

cat /proc/cpuinfo | grep processor | wc -l

The command just looks in the /proc/cpuinfo file, pulls out the number of lines containing the word "processor" and passes them into wc (word count), which returns a count of the CPUs in the system. Here's what it returned on my remote server:

[root@root]# cat /proc/cpuinfo | grep processor | wc -l

4

Note that if you have a dual-core processor, it will return each core as a separate processor. You can look at the full output of cat /proc/cpuinfo to see if the chips are dual-core.