Nproc is a Linux command that prints the number of available processor units in the system. This command is useful for system administrators who want to check the number of processors available on a system, and for users who want to optimize their applications to use all available processors.
Overview
To use the nproc command, open a terminal window and type nproc. The output will be the number of available processor units. For example, if the output is 8, it means that there are 8 processors available on the system.
$ nproc
8
The nproc command is often used in shell scripts to set the number of threads or processes to run in parallel. For example, to run a script with four threads, you can use the following command:
$ ./script.sh -t $(nproc)
This will run the script with four threads on a system with four or more processors.
Options
The nproc command has no options.
Troubleshooting tips
If the nproc command does not return any output, it may be because the command is not installed on the system. To install the command, use the following command:
$ sudo apt-get install coreutils
If the nproc command returns an error, it may be because the system does not have any processors. In this case, the system may be a virtual machine or a container that does not have access to the host system’s processors.
Notes
- The nproc command is part of the coreutils package, which is installed by default on most Linux distributions.
- The nproc command returns the number of available processor units, which may not be the same as the number of physical processors on the system. For example, a system with hyper-threading enabled may have twice as many available processor units as physical processors.