/proc/sysrq-trigger - SysRq function
- /proc/sysrq-trigger (since Linux 2.4.21)
- Writing a character to this file triggers the same SysRq function as
typing ALT-SysRq-<character> (see the description of
/proc/sys/kernel/sysrq). This file is normally writable only by
root. For further details see the Linux kernel source file
Documentation/admin-guide/sysrq.rst (or
Documentation/sysrq.txt before Linux 4.10).