/usr/sbin/safe_asterisk is in asterisk 1:11.13.1~dfsg-2+deb8u5.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215  | #!/bin/sh
ASTSBINDIR="/usr/sbin"
ASTVARRUNDIR="/var/run/asterisk"
ASTVARLOGDIR="/var/log/asterisk"
CLIARGS="$*"			# Grab any args passed to safe_asterisk
TTY=9				# TTY (if you want one) for Asterisk to run on
CONSOLE=yes			# Whether or not you want a console
#NOTIFY=root@localhost		# Who to notify about crashes
#EXEC=/path/to/somescript	# Run this command if Asterisk crashes
#LOGFILE="${ASTVARLOGDIR}/safe_asterisk.log"	# Where to place the normal logfile (disabled if blank)
#SYSLOG=local0			# Which syslog facility to use (disabled if blank)
MACHINE=`hostname`		# To specify which machine has crashed when getting the mail
DUMPDROP="${DUMPDROP:-/tmp}"
RUNDIR="${RUNDIR:-/tmp}"
SLEEPSECS=4
ASTPIDFILE="${ASTVARRUNDIR}/asterisk.pid"
# comment this line out to have this script _not_ kill all mpg123 processes when
# asterisk exits
KILLALLMPG123=1
# run asterisk with this priority
PRIORITY=0
# set system filemax on supported OSes if this variable is set
# SYSMAXFILES=262144
# Asterisk allows full permissions by default, so set a umask, if you want
# restricted permissions.
#UMASK=022
# set max files open with ulimit. On linux systems, this will be automatically
# set to the system's maximum files open devided by two, if not set here.
# MAXFILES=32768
message() {
	if test -n "$TTY" && test "$TTY" != "no"; then
		echo "$1" >/dev/${TTY}
	fi
	if test -n "$SYSLOG"; then
		logger -p "${SYSLOG}.warn" -t safe_asterisk[$$] "$1"
	fi
	if test -n "$LOGFILE"; then
		echo "safe_asterisk[$$]: $1" >>"$LOGFILE"
	fi
}
# Check if Asterisk is already running.  If it is, then bug out, because
# starting safe_asterisk when Asterisk is running is very bad.
VERSION=`"${ASTSBINDIR}/asterisk" -nrx 'core show version' 2>/dev/null`
if test "`echo $VERSION | cut -c 1-8`" = "Asterisk"; then
	message "Asterisk is already running.  $0 will exit now."
	exit 1
fi
# since we're going to change priority and open files limits, we need to be
# root. if running asterisk as other users, pass that to asterisk on the command
# line.
# if we're not root, fall back to standard everything.
if test `id -u` != 0; then
	echo "Oops. I'm not root. Falling back to standard prio and file max." >&2
	echo "This is NOT suitable for large systems." >&2
	PRIORITY=0
	message "safe_asterisk was started by `id -n` (uid `id -u`)."
else
	if `uname -s | grep Linux >/dev/null 2>&1`; then
		# maximum number of open files is set to the system maximum divided by two if
		# MAXFILES is not set.
		if test -z "$MAXFILES"; then
			# just check if file-max is readable
			if test -r /proc/sys/fs/file-max; then
				MAXFILES=$(( `cat /proc/sys/fs/file-max` / 2 ))
			fi
		fi
		SYSCTL_MAXFILES="fs.file-max"
	elif `uname -s | grep Darwin /dev/null 2>&1`; then
		SYSCTL_MAXFILES="kern.maxfiles"
	fi
	if test -n "$SYSMAXFILES"; then
		if test -n "$SYSCTL_MAXFILES"; then
			sysctl -w $SYSCTL_MAXFILES=$SYSMAXFILES
		fi
	fi
	# set the process's filemax to whatever set above
	ulimit -n $MAXFILES
	if test ! -d "${ASTVARRUNDIR}"; then
		mkdir -p "${ASTVARRUNDIR}"
		chmod 770 "${ASTVARRUNDIR}"
	fi
fi
if test -n "$UMASK"; then
	umask $UMASK
fi
#
# Let Asterisk dump core
#
ulimit -c unlimited
#
# Don't fork when running "safely"
#
ASTARGS=""
if test -n "$TTY" && test "$TTY" != "no"; then
	if test -c /dev/tty${TTY}; then
		TTY=tty${TTY}
	elif test -c /dev/vc/${TTY}; then
		TTY=vc/${TTY}
	else
		message "Cannot find specified TTY (${TTY})"
		exit 1
	fi
	ASTARGS="${ASTARGS} -vvvg"
	if test "$CONSOLE" != "no"; then
		ASTARGS="${ASTARGS} -c"
	fi
fi
if test ! -d "${RUNDIR}"; then
	message "${RUNDIR} does not exist, creating"
	if ! mkdir -p "${RUNDIR}"; then
		message "Unable to create ${RUNDIR}"
		exit 1
	fi
fi
if test ! -w "${DUMPDROP}"; then
	message "Cannot write to ${DUMPDROP}"
	exit 1
fi
#
# Don't die if stdout/stderr can't be written to
#
trap '' PIPE
#
# Run scripts to set any environment variables or do any other system-specific setup needed
#
if test -d /etc/asterisk/startup.d; then
	for script in /etc/asterisk/startup.d/*.sh; do
		if test -r ${script}; then
			. ${script}
		fi
	done
fi
run_asterisk()
{
	while :; do
		if test -n "$TTY" && test "$TTY" != "no"; then
			cd "${RUNDIR}"
			stty sane </dev/${TTY}
			nice -n $PRIORITY "${ASTSBINDIR}/asterisk" -f ${CLIARGS} ${ASTARGS} >/dev/${TTY} 2>&1 </dev/${TTY}
		else
			cd "${RUNDIR}"
			nice -n $PRIORITY "${ASTSBINDIR}/asterisk" -f ${CLIARGS} ${ASTARGS} >/dev/null 2>&1 </dev/null
		fi
		EXITSTATUS=$?
		message "Asterisk ended with exit status $EXITSTATUS"
		if test $EXITSTATUS -eq 0; then
			# Properly shutdown....
			message "Asterisk shutdown normally."
			exit 0
		elif test $EXITSTATUS -gt 128; then
			EXITSIGNAL=$((EXITSTATUS - 128))
			message "Exited on signal $EXITSIGNAL"
			if test -n "$NOTIFY"; then
				echo "Asterisk on $MACHINE exited on signal $EXITSIGNAL.  Might want to take a peek." | \
				mail -s "Asterisk Died" $NOTIFY
			fi
			if test -n "$EXEC"; then
				$EXEC
			fi
			PID=`cat ${ASTPIDFILE}`
			DATE=`date "+%Y-%m-%dT%H:%M:%S%z"`
			if test -f "${RUNDIR}/core.${PID}"; then
				mv "${RUNDIR}/core.${PID}" "${DUMPDROP}/core.`hostname`-$DATE" &
			elif test -f "${RUNDIR}/core"; then
				mv "${RUNDIR}/core" "${DUMPDROP}/core.`hostname`-$DATE" &
			fi
		else
			message "Asterisk died with code $EXITSTATUS."
			PID=`cat ${ASTPIDFILE}`
			DATE=`date "+%Y-%m-%dT%H:%M:%S%z"`
			if test -f "${RUNDIR}/core.${PID}"; then
				mv "${RUNDIR}/core.${PID}" "${DUMPDROP}/core.`hostname`-$DATE" &
			elif test -f "${RUNDIR}/core"; then
				mv "${RUNDIR}/core" "${DUMPDROP}/core.`hostname`-$DATE" &
			fi
		fi
		message "Automatically restarting Asterisk."
		sleep $SLEEPSECS
		if test "0$KILLALLMPG123" -gt 0; then
			pkill -9 mpg123
		fi
	done
}
if test -n "$ASTSAFE_FOREGROUND"; then
	run_asterisk
else
	run_asterisk &
fi
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