CHECKRESTART(1)

NAME
checkrestart - check for processes that may need restarting

SYNOPSIS
checkrestart [--libxo] [-bHw] [-j jail] [-u user] [proc ...]

DESCRIPTION
The checkrestart command attempts to find processes that need restarting following a software upgrade, as indicated by their underlying executable or shared libraries no longer appearing on disk.

checkrestart does not perform any system changes itself — it is strictly informational and best-effort (See the BUGS section). It is the responsibility of the system administrator to interpret the results and take any necessary action.

For full system-wide checks, checkrestart should be executed as the superuser to allow it access to global virtual memory mappings.

The following options are available:

--libxo
    Generate formatted output via libxo(3) in a selection of human and machine-readable formats. See xo_parse_args(3) for details on available arguments.

-b  Check only for missing binaries, skipping the far more expensive check for stale libraries.

-H  Suppress the header.

-w  Print the full width of the ARGUMENTS column even if it will wrap in the terminal.

-j jail
    Filter output by specified jail name or ID.

-u user
    Filter output by specified user name or ID.

If any proc operands are specified, they are treated as process names, IDs, and group IDs to limit checks to.

EXAMPLES
Check all processes visible by the user:

     # checkrestart
      PID   JID USER         COMMAND      WHY ARGUMENTS
    44960     0 freaky       weechat      .so /usr/local/bin/weechat
    81345     0 freaky       tmux         bin tmux: server (/tmp/tmux-1001/default)
    80307     0 freaky       tmux         bin tmux: client (/tmp/tmux-1001/default)
    18115     1 nobody       memcached    bin /usr/local/bin/memcached

This output indicates weechat is using an out of date library, a tmux client/server pair is using an out-of-date executable, having replaced its arguments list obscuring its location, and memcached, running in jail 1, is also out of date having left its arguments list as the full path to its original executable.

Check only processes named weechat and tmux:

     # checkrestart weechat tmux

Check only processes with PID 142 and 157:

     # checkrestart 142 157

Check only processes in PGID 117:

     # checkrestart -- -117

SEE ALSO
procstat(1), libxo(3), xo_parse_args(3), jail(8), service(8)

HISTORY
A checkrestart command first appeared in the debian-extras package in Debian Linux.

This implementation follows a similar idea, and is based on a prior version in the author's pkg-cruft Ruby script.

An unrelated but similar checkrestart command is also available as an OpenBSD port.

AUTHORS
Thomas Hurst <tom@hur.st>

BUGS
checkrestart may report both false positives and false negatives, depending on program and kernel behaviour, and should be considered strictly "best-effort".

In particular, retrieval of pathnames is implemented using the kernel's name cache — if an executable or library path is not in the name cache due to an eviction, or use of a file system which does not use the name cache, checkrestart will consider this the same as if a file is missing.

The use of the name cache also means it is not yet possible to report which files are considered missing.