# Linux Kernel Module Cheat

#### 27.4.5. sysconf

https://pubs.opengroup.org/onlinepubs/9699919799/functions/sysconf.html

Examples:

- userland/posix/sysconf.c

- userland/linux/sysconf.c showcases Linux extensions to POSIX

  Note that this blows up on gem5 userland due to `NPROCESSORS_ONLN` however: https://gem5.atlassian.net/browse/GEM5-622

Get lots of info on the system configuration.

The constants can also be viewed accessed on my Ubuntu 18.04 host with:

    getconf -a

`getconf` is also specified by POSIX at: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/getconf.html but not the `-a` option which shows all configurations.

Busybox 1.31.1 clearly states that `getconf` is not implemented however at `docs/posix_conformance.txt`:

    POSIX Tools not supported:
      asa, at, batch, bc, c99, command, compress, csplit, ex, fc, file,
      gencat, getconf, iconv, join, link, locale, localedef, lp, m4,