# proc_sys - system information, and sysctl pseudo-filesystem - man(5) - [phpMan]

[_proc_sys_(5)](https://www.chedong.com/phpMan.php/man/procsys/5/markdown)                              File Formats Manual                             [_proc_sys_(5)](https://www.chedong.com/phpMan.php/man/procsys/5/markdown)

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

## DESCRIPTION
       _/proc/sys/_
              This directory (present since Linux 1.3.57) contains a number of files and subdirecto‐
              ries corresponding to kernel variables.  These variables can be read and in some cases
              modified using the _/proc_ filesystem, and the (deprecated) [**sysctl**(2)](https://www.chedong.com/phpMan.php/man/sysctl/2/markdown) 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 sepa‐
              rators leads to the error **EINVAL**.

## SEE ALSO
       [**proc**(5)](https://www.chedong.com/phpMan.php/man/proc/5/markdown)

Linux man-pages 6.7                          2023-09-30                                  [_proc_sys_(5)](https://www.chedong.com/phpMan.php/man/procsys/5/markdown)