/proc/sys/ - system information, and sysctl pseudo-filesystem

/proc/sys/

This directory (present since Linux 1.3.57) contains a number of files and subdirectories corresponding to kernel variables. These variables can be read and in some cases modified using the /proc filesystem, and the (deprecated) sysctl(2) system call.

String values may be terminated by either '\0' or '\n'.

Integer and long values may be written either in decimal or in hexadecimal notation (e.g., 0x3FFF). When writing multiple integer or long values, these may be separated by any of the following whitespace characters: ' ', '\t', or '\n'. Using other separators leads to the error EINVAL.

proc(5)