Commit 21c9e3db authored by ssrq's avatar ssrq

[explorer/init] Support more init systems

parent 4fe2dcba
#!/bin/sh
#!/bin/sh -e
#
# 2016 Daniel Heule (hda at sfs.biz)
# Copyright 2017, Philippe Gregoire <pg@pgregoire.xyz>
# 2020 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
#
# This file is part of cdist.
#
......@@ -23,59 +24,181 @@
# for example at linux this value is "init" or "systemd" in most cases
#
set -e
# Expected values:
# Linux:
# Gentoo:
# sysvinit, openrc-init
# GNU:
# Debian:
# hurd-init, sysvinit
# [root@fedora-12 ~]# readlink /proc/1/exe
# /sbin/init (deleted)
# [root@fedora-12 ~]# ls -l /proc/1/exe
# lrwxrwxrwx. 1 root root 0 2020-01-30 23:00 /proc/1/exe -> /sbin/init (deleted)
# inspired by https://stackoverflow.com/a/33266819
shreadlink() (
CDPATH=
target=$1 fname= targetDir=
# Resolve potential symlinks until the ultimate target is found.
while :
do
if ! test -e "$target"
then
printf 'ERROR: %s does not exist.\n' "'$target'" >&2
return 1
fi
# Change to target dir; necessary for correct resolution of target path.
cd "$(dirname -- "$target")"
fname=$(basename -- "$target") # Extract filename.
[ "$fname" = '/' ] && fname='' # !! curiously, `basename /` returns '/'
[ -L "$fname" ] || break
# Extract [next] target path, which may be defined
# *relative* to the symlink's own directory.
# Note: We parse `ls -l` output to find the symlink target
# which is the only POSIX-compliant, albeit somewhat fragile, way.
# FIXME: Will break if one of the filenames contain ’ -> ’
target=$(ls -l "$fname" | sed -e 's/^.* -> //')
done
# Get canonical dir. path
targetDir=$(pwd -P)
# Output the ultimate target's canonical path.
# Note that we manually resolve paths ending in /. and /.. to make sure we have a normalized path.
if test "$fname" = '.'
then
printf '%s\n' "${targetDir%/}"
elif test "$fname" = '..'
then
# Caveat: something like /var/.. will resolve to /private (assuming /var@ -> /private/var), i.e. the '..' is applied
# AFTER canonicalization.
printf '%s\n' "$(dirname -- "${targetDir}")"
else
printf '%s/%s\n' "${targetDir%/}" "$fname"
fi
)
case $(uname -s) in
Linux)
if test -d /proc/1/
then
comm_name=$(cat /proc/1/comm)
else
# BusyBox's versions of ps and pgrep do not support some options
# depending on which compile-time options have been used.
# Both pgrep and ps are tried to get the command name
comm_name=$(
pgrep -P0 -l 2>/dev/null | awk '/^1[ \t]/ { print $2 }'
|| ps -o comm= -p 1 2>/dev/null)
fi
case $comm_name
in
systemd)
echo systemd
;;
init)
# It could be anything...
if test -h /proc/1/exe
then
init_exe=/proc/1/exe
else
init_exe=$(command -v "$comm_name")
fi
test -x "$comm_exe" || exit 1
case $("$comm_exe" --version | head -n 1)
in
*SysV*)
echo init
;;
*upstart*)
echo upstart
;;
*)
echo ""
;;
esac
esac
;;
FreeBSD|OpenBSD)
ps -o comm= -p 1 2>/dev/null || true
;;
Darwin)
basename "$(ps -o comm= -p 1 2>/dev/null)"
;;
*)
# return a empty string as unknown value
echo ""
;;
Linux|GNU)
# if test -f /proc/1/comm
# then
# comm_name=$(cat /proc/1/comm)
# else
# BusyBox's versions of ps and pgrep do not support some options
# depending on which compile-time options have been used.
# Both pgrep and ps are tried to get the command name
# comm_name=$(
# pgrep -P0 -l 2>/dev/null | awk '/^1[ \t]/ { print $2 }'
# || ps -o comm= -p 1 2>/dev/null)
# fi
init_exe=$(shreadlink /proc/1/exe)
if ! test -x "$init_exe"
then
# On some rare occasions it can happen that the
# running init's binary has been replaced. In this
# case Linux adjusts the symlink to "X (deleted)"
case $init_exe
in
*' (deleted)')
init_exe=${init_exe% (deleted)}
test -x "$init_exe" || exit 1
;;
*)
exit 1
;;
esac
fi
if test "$init_exe" = '/hurd/init'
then
# XXX: Could maybe be removed
echo hurd-init
exit 0
fi
comm_name=$(basename "$init_exe")
case $comm_name
in
init)
: # handled below
;;
systemd)
# NOTE: sd_booted(3)
if test -d /run/systemd/system/
then
echo systemd
exit 0
fi
# otherwise: treat like "init"
;;
*)
echo "$comm_name"
exit 0
;;
esac
# init: it could be anything...
case $("$init_exe" --version 2>/dev/null | head -n 1)
in
SysV*)
# This is a little bit more specific than init
echo sysvinit
exit 0
;;
*'GNU Hurd'*)
echo hurd-init
;;
*upstart*)
echo upstart
exit 0
;;
esac
case $("$init_exe" --help 2>/dev/null | head -n 1)
in
BusyBox*)
echo busybox
exit 0
;;
esac
echo init
;;
FreeBSD|OpenBSD)
ps -o comm= -p 1 2>/dev/null || true
;;
Darwin)
basename "$(ps -o comm= -p 1 2>/dev/null)"
;;
SunOS)
comm_name=$(ps -o comm= -p 1 2>/dev/null)
if test "$(basename "$comm_name")" != 'init'
then
echo "${comm_name}"
exit 0
fi
# XXX: Is this the correct way??
if test -f /etc/svc/volatile/svc_nonpersist.db
then
echo smf
exit 0
fi
;;
*)
# return a empty string as unknown value
echo ""
;;
esac
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