+trap 'rm -f $TMP_BASE*' 0 1 2 3 15
+
+## --------------------------------- ##
+## Skip if user does not have perl. ##
+## --------------------------------- ##
+
+TMP=$TMP_BASE
+s=$TMP-script
+cat <<\EOF > $s
+eval '(exit $?0)' && eval 'exec perl -wS -0777 -pi "$0" ${1+"$@"}'
+ & eval 'exec perl -wS -0777 -pi "$0" $argv:q'
+ if 0;
+s/a/b/
+EOF
+chmod a+x $s
+echo a > $TMP-in
+./$s $TMP-in 2>/dev/null && test b = "`cat $TMP-in 2>/dev/null`" ||
+ {
+ printf '%s\n' "$0: skipping this test;" \
+ 'your system has insufficient support for Perl' 1>&2
+ exit 77
+ }
+
+# Do not let a different envvar setting perturb results.
+UPDATE_COPYRIGHT_MAX_LINE_LENGTH=72
+export UPDATE_COPYRIGHT_MAX_LINE_LENGTH