wcheckrestart

#!/bin/sh
# wcheckrestart (part of ossobv/vcutil) // wdoekes/2014,2018,2020
#   // Public Domain
#
# Checks which services need to be restarted after an upgrade. Inspired
# by:
# - checkrestart (from debian-goodies), a more complicated version of this
# - https://locallost.net/?p=233
# - http://askubuntu.com/questions/194/how-can-i-install-just-\
#     security-updates-from-the-command-line
#
# Usage:
#
#    sudo wcheckrestart [-v] [options_to_ps]
#    sudo wcheckrestart -vv
#    sudo wcheckrestart -sd | sudo xargs systemctl restart
#
# Examples:
#
#    # Check which processes need a restart and restart them.
#    sudo wcheckrestart
#    sudo /etc/init.d/this-and-that restart  # :)
#
#    # Check which PIDs still have an old libssl loaded.
#    sudo wcheckrestart -vv | grep libssl
#
#    # Pass options 'h' and '-o pid' to 'ps', to get the PIDs only.
#    sudo wcheckrestart -v h -o pid  # | awk NF=NF RS= OFS=,
#
verbose=0
options_to_ps=f
if test "$*" = "-sd"; then
    verbose=-1
elif test "$*" = "-vv"; then
    verbose=2
elif test "$1" = "-v"; then
    verbose=1
    shift
fi
if test -n "$*"; then
    options_to_ps="$@"
fi

if test $(whoami) != root; then
    echo "must be root" 2>/dev/null
    exit 1
fi

shown=""
toshow=""

# Create a regex of PIDs '^ *123 |^ *456 ' based on all processes that have
# "(deleted)" so files, according to /proc/PID/maps.
# (Some java processes create a temporary dynamic library as /tmp/*.so
# and delete it after load. We exclude those.)
pids=$(find /proc -maxdepth 2 -name maps -path '/proc/[0-9]*/maps' \
         2>/dev/null |
       xargs grep -E '\.so(\..*)? \(deleted\)$' /dev/null 2>/dev/null |
       grep -v '[[:blank:]]/tmp/' |
       sed -e 's#/proc/\([0-9]*\)/.*$#^ *\1 #' | uniq | tr '\n' '|' |
       sed -e 's/|$//')
test -z "$pids" && exit 0

# call `ps fhax` to get sane sorting (parents first)
for pids in $(ps fhax -opid,ppid | grep -E "$pids" |
              sed -e 's/^ *//;s/ *$//;s/ \+/,/'); do
    pid=${pids%,*}
    ppid=${pids#*,}
    shown="$shown $pid "

    exe=$(readlink /proc/$pid/exe 2>/dev/null) || continue
    # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=777691
    # Ignore dbus; right now it cannot be restarted without rebooting the
    # system. Don't tempt the user to try and find a way.
    test "$exe" = "/usr/bin/dbus-daemon" && continue
    test "$exe" = "/usr/bin/dbus-daemon (deleted)" && continue

    # If not verbose, and parentpid is not 1 (in case we've already
    # shown /sbin/init) and we've already added the parent, then
    # don't show it.
    test $verbose -le 0 && test $ppid != 1 &&
        test "$shown" != "${shown% $ppid *}" &&
        continue

    toshow="$toshow,$pid"
    if test $verbose -ge 2; then
        cmdline=$(tr '\0' ' ' </proc/$pid/cmdline)
        echo "PID $pid $cmdline"
        grep -E '\.so(\..*)? \(deleted\)$' /proc/$pid/maps 2>/dev/null |
            sed -e "s/^/    $pid /"
        echo
    fi
done

if test -n "$toshow"; then
    if test $verbose -eq -1; then
        # "* some.service - Some Service"
        LC_ALL=C systemctl status $(echo "$toshow" | sed -e 's/^.//;s/,/ /g') |
            sed '/^[*] .* - .*/!d;s/^[^ ] //;s/ - .*//;/[.]scope$/d' | sort -u
    elif test $verbose -le 1; then
        ps $options_to_ps -p $(echo "$toshow" | sed -e 's/^.//')
    fi
fi

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