Add RR: run command until failure

Makefile

@@ -1,7 +1,7 @@
 prefix=$$HOME/opt/pkg/miscutils
 target_bin=${prefix}/bin
 target_man=${prefix}/share/man/man1
-bin=bwrap hppt mkgmap newp rot scmfmt upcasetl unpage
+bin=bwrap hppt mkgmap newp rot rr scmfmt upcasetl unpage
 install:
 	install -d ${target_bin} ${target_man}
 	install -c ${bin} ${target_bin}

rr

@@ -0,0 +1,16 @@
+#!/bin/sh
+[ $# -eq 1 ] && echo "usage: $0 command ..." && exit 64
+tmp1=$(mktemp $0.XXXXXXXXXX)
+tmp2=$(mktemp $0.XXXXXXXXXX)
+trap "rm $tmp1 $tmp2; exit 0" 1 2 15
+while "$@" >$tmp2
+do
+	if ! diff $tmp1 $tmp2
+	then
+		cp $tmp2 $tmp1
+	else
+		echo -n "."
+	fi
+	sleep 2
+done
+rm $tmp1 $tmp2

rr.1

@@ -0,0 +1,30 @@
+.Dd Jun 10, 2022
+.Dt RR 1
+.Os
+.Sh NAME
+.Nm rr
+.Nd Repeteadly run a command until it exits with a non zero status
+.Sh SYNOPSIS
+.Nm
+.Ar cmd Op Ar arg ...
+.Sh DESCRIPTION
+Run command
+.Ar cmd arg ...
+repeteadly until it fails.
+.Pp
+In every run, compare its stdout with the one from the previous run.
+If there has been any change, print a diff;
+otherwise, display a dot to indicate progress.
+.Sh EXIT STATUS
+.Ex -std
+.Sh EXAMPLES
+.Bd -literal -offset indent
+$ rr pgrep -f foo
+0a1,2
+> 6871
+> 25428
+\&...^C
+$
+.Ed
+.Sh AUTHORS
+.An Adolfo Perez Alvarez Aq Mt adolfopa@sdf.org