find-first-fail: Bug if multiple options fixed.

Makefile

@@ -1,14 +1,14 @@
-CMD = binsearch blink 2grep 2search burncpu drac duplicate-packets em	\
-	encdir field forever fxkill G gitnext gitundo goodpasswd	\
-	histogram mtrr mirrorpdf neno off parsort pdfman pidcmd		\
-	pidtree plotpipe puniq ramusage rand rclean rina rn rrm		\
-	seekmaniac shython sound-reload splitvideo stdout swapout T	\
-	teetime timestamp tracefile transpose upsidedown vid		\
+CMD = blink 2grep 2search burncpu drac duplicate-packets em encdir	\
+	field find-first-fail forever fxkill G gitnext gitundo		\
+	goodpasswd histogram mtrr mirrorpdf neno off parsort pdfman	\
+	pidcmd pidtree plotpipe puniq ramusage rand rclean rina rn	\
+	rrm seekmaniac shython sound-reload splitvideo stdout swapout	\
+	T teetime timestamp tracefile transpose upsidedown vid		\
 	w4it-for-port-open whitehash wifi-reload wssh ytv yyyymmdd
 
-all: binsearch/binsearch.1 blink/blink.1 2search/2grep.1		\
-	2search/2search.1 burncpu/burncpu.1 drac/drac.1			\
-	encdir/encdir.1 field/field.1 G/G.1 gitnext/gitnext.1		\
+all: blink/blink.1 2search/2grep.1 2search/2search.1			\
+	burncpu/burncpu.1 drac/drac.1 encdir/encdir.1 field/field.1	\
+	find-first-fail/find-first-fail.1 G/G.1 gitnext/gitnext.1	\
 	gitundo/gitundo.1 goodpasswd/goodpasswd.1			\
 	histogram/histogram.1 mirrorpdf/mirrorpdf.1 neno/neno.1		\
 	off/off.1 parsort/parsort.1 pdfman/pdfman.1 pidcmd/pidcmd.1	\

find-first-fail/find-first-fail

@@ -18,12 +18,13 @@ B<find-first-fail> [-2] [-q] [-s I<start>] I<command>
 B<find-first-fail> runs I<command> with a single number. It returns highest
 value that I<command> succeeds for.
 
-It finds the value by first testing the value 1. As long as the value
-succeeds, the value is doubled. When the value fails, B<find-first-fail>
-does a binary search between this value and the previous value.
+It finds the value by first testing the I<start> value (which defaults
+to 1). As long as the value succeeds, the value is doubled. When the
+value fails, B<find-first-fail> does a binary search between this
+value and the previous value.
 
-If the value 1 fails, B<find-first-fail> instead searches for the highest
-value that I<command> fails for.
+If the I<start> value fails, B<find-first-fail> instead searches for
+the highest value that I<command> fails for.
 
 
 =head1 OPTIONS
@@ -43,6 +44,10 @@ Quiet. Ignore output from I<command>.
 
 Start searching from the value I<start>. Normally searching will start from the value 1.
 
+=item B<-v>
+
+Verbose. Show the commands being run.
+
 
 =back
 
@@ -89,6 +94,20 @@ Complex commands can also be run:
   find-first-fail -v perl -e 'exit(shift > 129)'
 
 
+=head2 Find the second limit of a program
+
+Assume you have a program that is OK in the range 123..12345. How do
+you find the limits?
+
+    myprog() { perl -e '$a=shift;if($a <= 123) { exit 0; }
+    	       	        else { exit ($a <= 12345) }' "$@"; }
+    export -f myprog
+    # Finds 123
+    find-first-fail myprog
+    # Finds 12345
+    find-first-fail -s 200 myprog
+
+
 =head1 AUTHOR
 
 Copyright (C) 2020 Ole Tange,
@@ -121,15 +140,16 @@ B<eval>(1)
 
 find-first-fail() {
     _find-first-fail() {
-	low=$1
-	high=$2
+	local low=$1
+	local high=$2
 	# echo $low-$high
 	if [ $low -gt $(($high - 2)) ]; then
+	    echo $low
 	    return
 	fi
 	shift
 	shift
-	middle=$(( ( $low + $high ) / 2 ))
+	local middle=$(( ( $low + $high ) / 2 ))
 	if _run $low $middle "$@" ; then
 	    low=$middle
 	else
@@ -165,24 +185,25 @@ find-first-fail() {
 	eval "$not" _inner_run "$quiet"
     }
 
-    quiet=""
-    opt2=false
-    verbose=false
-    start=1
+    local opt2=false
+    local quiet=""
+    local start=1
+    local verbose=false
     
     # Parse and remove options
-    while getopts "2vqs:" options; do
+    while getopts "2qs:v" options; do
 	case "${options}" in
 	    (2)   opt2=true;;
 	    (q)   quiet=">/dev/null 2>/dev/null";;
+	    (s)   start="$OPTARG";;
 	    (v)   verbose=true;;
-	    (s)   start="$2";;
 	    (-)   break;;
 	esac
     done
     shift $(( OPTIND - 1))
     
     # If function(1) = false: run 'not function()' instead
+    local not
     if _run "$start" "$start" "$@" ; then
 	not=''
     else
@@ -192,7 +213,8 @@ find-first-fail() {
     # exponential search for the first value that is false
     # low = previous value (function($low) == true)
     # high = low * 2 (function($high) == false)
-    high=$start
+    local high=$start
+    local low
     while _run $start $high "$@" ; do
 	low=$high
 	high=$(( $high*2 ))
@@ -207,7 +229,7 @@ find-first-fail() {
     # Search low..high
     # echo "low: $low high: $high not: $not"
     _find-first-fail $low $high "$@" 2>/dev/null
-    echo $low
+    unset low high start
 }
 
 if [ -z "$*" ] ; then

find-first-fail/testsuite

@@ -0,0 +1,38 @@
+#!/bin/bash
+
+test_unexported_function() {
+    myprog() { perl -e 'exit (shift > 12345678)' "$@"; }
+    # myprog is a function, so source find-first-fail first
+    . `which find-first-fail`
+    find-first-fail myprog
+}
+
+test_exported_function() {
+    myprog() { perl -e 'exit (shift > 12345678)' "$@"; }
+    # myprog is an exported function
+    export -f myprog
+    find-first-fail myprog
+}
+
+test_startvalue() {
+    # exit value changes at 100 and 12345678
+    myprog() { perl -e '$a=shift;if($a <= 123) { exit 0; }
+    	       	        else { exit ($a <= 12345678) }' "$@"; }
+    export -f myprog
+    # Finds 123
+    find-first-fail myprog
+    # Finds 12345678
+    find-first-fail -s 200 myprog
+}
+
+test_s_v_12() {
+    # Multiple options
+    myprog() { perl -e 'exit (shift > 12)' "$@"; }
+    export -f myprog
+    find-first-fail -v -s 10 myprog
+    find-first-fail -v -q -s 10 myprog
+}
+
+export -f $(compgen -A function | grep test_)
+compgen -A function | grep test_ | LC_ALL=C sort |
+    parallel --timeout 1000% --tag -k --joblog /tmp/jl-`basename $0` '{} 2>&1'