binsearch: Initial version.
This commit is contained in:
parent
a9e198cd43
commit
4206374f37
29
Makefile
29
Makefile
|
@ -1,19 +1,20 @@
|
|||
CMD = 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 = 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 \
|
||||
w4it-for-port-open whitehash wifi-reload wssh ytv yyyymmdd
|
||||
|
||||
all: 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 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 pidtree/pidtree.1 \
|
||||
plotpipe/plotpipe.1 puniq/puniq.1 rand/rand.1 rina/rina.1 \
|
||||
rn/rn.1 rrm/rrm.1 seekmaniac/seekmaniac.1 shython/shython.1 \
|
||||
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 \
|
||||
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 \
|
||||
pidtree/pidtree.1 plotpipe/plotpipe.1 puniq/puniq.1 \
|
||||
rand/rand.1 rina/rina.1 rn/rn.1 rrm/rrm.1 \
|
||||
seekmaniac/seekmaniac.1 shython/shython.1 \
|
||||
sound-reload/sound-reload.1 splitvideo/splitvideo.1 \
|
||||
stdout/stdout.1 teetime/teetime.1 timestamp/timestamp.1 \
|
||||
tracefile/tracefile.1 transpose/transpose.1 T/T.1 \
|
||||
|
|
122
binsearch/binsearch
Executable file
122
binsearch/binsearch
Executable file
|
@ -0,0 +1,122 @@
|
|||
#!/bin/bash
|
||||
|
||||
: <<'=cut'
|
||||
=encoding utf8
|
||||
|
||||
=head1 NAME
|
||||
|
||||
binsearch - do binary search to find a numeric limit
|
||||
|
||||
|
||||
=head1 SYNOPSIS
|
||||
|
||||
B<binsearch> I<command>
|
||||
|
||||
|
||||
=head1 DESCRIPTION
|
||||
|
||||
B<binsearch> runs I<command> with a single number. It returns highest
|
||||
value that I<command> succeeds for.
|
||||
|
||||
|
||||
=head1 EXAMPLES
|
||||
|
||||
=head2 Test a bash function
|
||||
|
||||
. $(which binsearch)
|
||||
singleecho() {
|
||||
/bin/echo $(perl -e 'print "x"x'$1) >/dev/null
|
||||
}
|
||||
binsearch singleecho
|
||||
|
||||
|
||||
=head1 AUTHOR
|
||||
|
||||
Copyright (C) 2020 Ole Tange,
|
||||
http://ole.tange.dk and Free Software Foundation, Inc.
|
||||
|
||||
|
||||
=head1 LICENSE
|
||||
|
||||
Copyright (C) 2012 Free Software Foundation, Inc.
|
||||
|
||||
This program is free software; you can redistribute it and/or modify
|
||||
it under the terms of the GNU General Public License as published by
|
||||
the Free Software Foundation; either version 3 of the License, or
|
||||
at your option any later version.
|
||||
|
||||
This program is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
GNU General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
|
||||
|
||||
=head1 SEE ALSO
|
||||
|
||||
B<eval>(1)
|
||||
|
||||
=cut
|
||||
|
||||
|
||||
# Example: find the max line length
|
||||
#
|
||||
# singleecho() {
|
||||
# /bin/echo $(perl -e 'print "x"x'$1) >/dev/null
|
||||
# }
|
||||
#
|
||||
# multiecho() {
|
||||
# /bin/echo $(perl -e 'print "x "x'$(($1/2)) ) >/dev/null
|
||||
# }
|
||||
#
|
||||
# binsearch singleecho
|
||||
|
||||
binsearch() {
|
||||
_binsearch() {
|
||||
low=$1
|
||||
high=$2
|
||||
# echo $low-$high
|
||||
if [ $low -gt $(($high - 2)) ]; then
|
||||
return
|
||||
fi
|
||||
shift
|
||||
shift
|
||||
middle=$(( ( $low + $high ) / 2 ))
|
||||
if eval "$@ $middle" ; then
|
||||
low=$middle
|
||||
else
|
||||
high=$middle
|
||||
fi
|
||||
_binsearch $low $high "$@"
|
||||
}
|
||||
|
||||
low=1
|
||||
# If function(1) = false: run 'not function()' instead
|
||||
if eval "$@ $low" ; then
|
||||
not=''
|
||||
else
|
||||
not='!'
|
||||
fi
|
||||
# exponential search for the first value that is false
|
||||
# low = previous value (function($low) == true)
|
||||
# high = low * 2 (function($high) == false)
|
||||
high=$low
|
||||
while eval "$not" "$@ $high" 2>/dev/null ; do
|
||||
low=$high
|
||||
high=$(( $high*2 ))
|
||||
done
|
||||
# echo "low: $low high: $high not: $not"
|
||||
_binsearch $low $high "$not $@" 2>/dev/null
|
||||
echo $low
|
||||
}
|
||||
|
||||
if [ -z "$@" ] ; then
|
||||
# source the bash function
|
||||
# . $(which binsearch)
|
||||
true
|
||||
else
|
||||
# binsearch command
|
||||
binsearch "$@"
|
||||
fi
|
Loading…
Reference in a new issue