find-first-fail: -s start value for searching.

find-first-fail/find-first-fail

@@ -10,7 +10,7 @@ find-first-fail - find the lowest argument that makes a command fail
 
 =head1 SYNOPSIS
 
-B<find-first-fail> [-2] [-q] I<command>
+B<find-first-fail> [-2] [-q] [-s I<start>] I<command>
 
 
 =head1 DESCRIPTION
@@ -39,6 +39,10 @@ arguments: I<from> I<to>.
 
 Quiet. Ignore output from I<command>.
 
+=item B<-s I<start>>
+
+Start searching from the value I<start>. Normally searching will start from the value 1.
+
 
 =back
 
@@ -164,20 +168,22 @@ find-first-fail() {
     quiet=""
     opt2=false
     verbose=false
+    start=1
     
     # Parse and remove options
-    while getopts "2vq" options; do
+    while getopts "2vqs:" options; do
 	case "${options}" in
 	    (2)   opt2=true;;
 	    (q)   quiet=">/dev/null 2>/dev/null";;
 	    (v)   verbose=true;;
+	    (s)   start="$2";;
 	    (-)   break;;
 	esac
     done
     shift $(( OPTIND - 1))
     
     # If function(1) = false: run 'not function()' instead
-    if _run 1 1 "$@" ; then
+    if _run "$start" "$start" "$@" ; then
 	not=''
     else
 	not='!'
@@ -186,8 +192,8 @@ find-first-fail() {
     # exponential search for the first value that is false
     # low = previous value (function($low) == true)
     # high = low * 2 (function($high) == false)
-    high=1
-    while _run 1 $high "$@" ; do
+    high=$start
+    while _run $start $high "$@" ; do
 	low=$high
 	high=$(( $high*2 ))
 	if [ $high -gt 4611686018427387900 ] ; then