Q: Is SQRT(n) possible in a POSIX compliant shell? A: Yes within limits. Post: 303039666

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Top Forums Shell Programming and Scripting Q: Is SQRT(n) possible in a POSIX compliant shell? A: Yes within limits. Post 303039666 by wisecracker on Friday 11th of October 2019 10:51:01 AM

10-11-2019

Registered User

;oDD

I showed it to the wife and I said 'what sticks out the most?'
She said the 'pink obviously!'

Anyhow here is an add-on to get Fixed Point Numbers SQRT from .100 to 9200000.000 using 'sqrt_bash.sh' edited to 32 bit mode.
All entries MUST be Fixed Point values even if they end in ?.000...

Code:

#!/usr/local/bin/dash
# FP_sqrt.sh
#
# Requires sqrt_dash.sh to work.
# This MUST be 3 decimal places only using 'sqrt_bash.sh' in 32 bit mode running in 64 bit.
#
# Usage: [full/path/to/][./]FP_sqrt.sh <.100_to_a_little_over_9200000.000>
#
# Note: numbers below 1.000 the input must be .??? format without the leading zero.
# The errors below .100 grow exponentially so values cannot to be trusted.

NUMBER=${1}

# Step 1, allocate this to _fractional_ part.
FRACT="${NUMBER##*.}"

# Step 2, get _whole_number_ part.
WHOLE="${NUMBER%%.*}"

# Step 3, put WHOLE and FRACT together and include 3 zeros.
NUMBER="${WHOLE}${FRACT}"'000'

# Step 4, call "sqrt_dash.sh" with new NUMBER into a variable.
NUMBER=$( ./sqrt_dash.sh "${NUMBER}" )

printf "%.3f\n" ${NUMBER}e-3

Results, confirmed by Google. Same MBP platform as always.

Code:

Last login: Fri Oct 11 15:15:40 on ttys000
AMIGA:amiga~> cd Desktop/Code/Shell
AMIGA:amiga~/Desktop/Code/Shell> ./FP_sqrt.sh .100
0.316
AMIGA:amiga~/Desktop/Code/Shell> ./FP_sqrt.sh .250
0.500
AMIGA:amiga~/Desktop/Code/Shell> ./FP_sqrt.sh .500
0.707
AMIGA:amiga~/Desktop/Code/Shell> ./FP_sqrt.sh .750
0.866
AMIGA:amiga~/Desktop/Code/Shell> ./FP_sqrt.sh 1.000
1.000
AMIGA:amiga~/Desktop/Code/Shell> ./FP_sqrt.sh 2.000
1.414
AMIGA:amiga~/Desktop/Code/Shell> ./FP_sqrt.sh 20.000
4.472
AMIGA:amiga~/Desktop/Code/Shell> ./FP_sqrt.sh 200.000
14.142
AMIGA:amiga~/Desktop/Code/Shell> ./FP_sqrt.sh 333.333
18.257
AMIGA:amiga~/Desktop/Code/Shell> ./FP_sqrt.sh 777.777
27.889
AMIGA:amiga~/Desktop/Code/Shell> ./FP_sqrt.sh 9187233.598
3031.045
AMIGA:amiga~/Desktop/Code/Shell> _

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cpanplus::shell

CPANPLUS::Shell(3pm)					 Perl Programmers Reference Guide				      CPANPLUS::Shell(3pm)

NAME

       CPANPLUS::Shell

SYNOPSIS

	   use CPANPLUS::Shell; 	    # load the shell indicated by your
					    # config -- defaults to
					    # CPANPLUS::Shell::Default

	   use CPANPLUS::Shell qw[Classic]  # load CPANPLUS::Shell::Classic;

	   my $ui      = CPANPLUS::Shell->new();
	   my $name    = $ui->which;	    # Find out what shell you loaded

	   $ui->shell;			    # run the ui shell

DESCRIPTION

       This module is the generic loading (and base class) for all "CPANPLUS" shells. Through this module you can load any installed "CPANPLUS"
       shell.

       Just about all the functionality is provided by the shell that you have loaded, and not by this class (which merely functions as a generic
       loading class), so please consult the documentation of your shell of choice.

BUG REPORTS

       Please report bugs or other issues to <bug-cpanplus@rt.cpan.org<gt>.

AUTHOR

       This module by Jos Boumans <kane@cpan.org>.

COPYRIGHT

       The CPAN++ interface (of which this module is a part of) is copyright (c) 2001 - 2007, Jos Boumans <kane@cpan.org>. All rights reserved.

       This library is free software; you may redistribute and/or modify it under the same terms as Perl itself.

SEE ALSO

       CPANPLUS::Shell::Default, CPANPLUS::Shell::Classic, cpanp

perl v5.12.1							    2010-04-26						      CPANPLUS::Shell(3pm)