periodic: Make daily diff(1) flags configurable with daily_diff_flags

PR:		270266
Approved by:	jrm (mentor), karels
MFC after:	1 month
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D42900

share/man/man5/periodic.conf.5

@@ -639,6 +639,11 @@ but specific to the pool
 Set to a list of extra scripts that should be run after all other
 daily scripts.
 All scripts must be absolute path names.
+.It Va daily_diff_flags
+.Pq Vt str
+Set to the arguments to pass to the
+.Xr diff 1
+utility when generating differences.
 .El
 .Pp
 The following variables are used by the standard scripts that reside in

usr.sbin/periodic/etc/daily/200.backup-passwd

@@ -40,7 +40,7 @@ case "$daily_backup_passwd_enable" in
 	    then
 		[ $rc -lt 1 ] && rc=1
 		echo "$host passwd diffs:"
-		diff -uI '^#' $bak/master.passwd.bak /etc/master.passwd |\
+		diff ${daily_diff_flags:--u} -I '^#' $bak/master.passwd.bak /etc/master.passwd |\
 			sed 's/^\([-+ ][^:]*\):[^:]*:/\1:(password):/'
 		mv $bak/master.passwd.bak $bak/master.passwd.bak2
 		cp -p /etc/master.passwd $bak/master.passwd.bak || rc=3
@@ -57,7 +57,7 @@ case "$daily_backup_passwd_enable" in
 	    then
 		[ $rc -lt 1 ] && rc=1
 		echo "$host group diffs:"
-		diff -u $bak/group.bak /etc/group
+		diff ${daily_diff_flags:--u} $bak/group.bak /etc/group
 		mv $bak/group.bak $bak/group.bak2
 		cp -p /etc/group $bak/group.bak || rc=3
 	    fi

usr.sbin/periodic/etc/daily/210.backup-aliases

@@ -34,7 +34,7 @@ case "$daily_backup_aliases_enable" in
 	    then
 		[ $rc -lt 1 ] && rc=1
 		echo "$host aliases diffs:"
-		diff -u $bak/aliases.bak /etc/mail/aliases
+		diff ${daily_diff_flags:--u} $bak/aliases.bak /etc/mail/aliases
 		mv $bak/aliases.bak $bak/aliases.bak2
 		cp -p /etc/mail/aliases $bak/aliases.bak || rc=3
 	    fi

usr.sbin/periodic/etc/daily/221.backup-gpart

@@ -27,7 +27,7 @@ rotate() {
 			rm "${file}.tmp"
 		else
 			rc=1
-			[ -n "$show_diff" ] && diff "${file}.bak" "${file}.tmp"
+			[ -n "$show_diff" ] && diff ${daily_diff_flags} "${file}.bak" "${file}.tmp"
 			mv "${file}.bak" "${file}.bak2" || rc=3
 			mv "${file}.tmp" "${file}.bak" || rc=3
 		fi

usr.sbin/periodic/etc/daily/222.backup-gmirror

@@ -25,7 +25,7 @@ rotate() {
 			rm "${file}.tmp"
 		else
 			rc=1
-			[ -n "$show_diff" ] && diff "${file}.bak" "${file}.tmp"
+			[ -n "$show_diff" ] && diff ${daily_diff_flags} "${file}.bak" "${file}.tmp"
 			mv "${file}.bak" "${file}.bak2" || rc=3
 			mv "${file}.tmp" "${file}.bak" || rc=3
 		fi

usr.sbin/periodic/etc/daily/223.backup-zfs

@@ -25,7 +25,7 @@ rotate() {
 			rm "${file}.tmp"
 		else
 			rc=1
-			[ -n "$show_diff" ] && diff "${file}.bak" "${file}.tmp"
+			[ -n "$show_diff" ] && diff ${daily_diff_flags} "${file}.bak" "${file}.tmp"
 			mv "${file}.bak" "${file}.bak2" || rc=3
 			mv "${file}.tmp" "${file}.bak" || rc=3
 		fi

usr.sbin/periodic/periodic.conf

@@ -31,6 +31,7 @@ anticongestion_sleeptime=3600
 # that output.  $daily_output might be set to /var/log/daily.log if you
 # wish to log the daily output and have the files rotated by newsyslog(8)
 #
+daily_diff_flags=""					# flags for diff output
 daily_output="root"					# user or /file
 daily_show_success="YES"				# scripts returning 0
 daily_show_info="YES"					# scripts returning 1