typeset -i in Linux

[alexvai]

Hi,
I have this command in ksh:

1. typeset -i INTEGER
INTEGER=aaa
In all platforms except of Linux it is failing and return exit code 1

Why in Linux it is not failing? I must it for my number tests

2. The same for printf command. Only in Linux the bellow command is not failing:
printf "%d" aaa

[Kloschüssel]

typeset may automatically determine the base16 representation of the number passed in?

"aaa" (base16) = "101010101010" (base2) = "2730" (base10)

on which other system (non-linux) does this command fail? solaris? mac?

[alexvai]

On AIX/HP/Sun it is failing:

$ typeset -i INTEGER
$ INTEGER=aaa
ksh: aaa: bad number

[Kloschüssel]

it will be implementation (and hence also version) specific. it's not the first time that a command works on one box but not on the other with a slightly older kernel.

man typeset yields for the -i option:

-i[base]
An integer. base represents the arithmetic base from 2 to 64. The option value may be omitted. The default value is 10.

[...]

IMPLEMENTATION

version
typeset (AT&T Research) 2008-08-04
author
David Korn <dgk@research.att.com>
copyright
Copyright © 1982-2010 AT&T Intellectual Property
license
http://www.opensource.org/licenses/cpl1.0.txt

[clowenstein]

Have you tried
$ INTEGER=0xaaa

[jippie]

Do a proper input sanity check.
Something like:

[ $INTEGER -ge 0 -o $INTEGER -le 0 ] 2> /dev/null && echo "Yes it is an integer"

which is in pseudo code something like:

if
    ( $INTEGER >= 0 )
or
    ( $INTEGER <= 0 )
then
    print "Yes it is an integer"
endif

[lomcevak]

I assume you’re porting ksh scripts to Linux. You will find minor differences in how ksh behaves on Linux than non-Linux systems. I know full well because we had to port ksh scripts from Tru64 to Linux and the minor differences caused us headaches. With your example Linux ksh will assign the value of 0 when you try to assign a non-numeric value to an integer variable.

#!/bin/ksh -v
typeset -i INTEGER
INTEGER=aaa
echo $INTEGER
0

As mentioned on Linux you’d have to validate the data to mimic the behavior on the non-Linux systems. Here’s a (crude) example:

VALUE=aaa
if [[ $(echo $VALUE | grep -q '^[0-9]*$'; echo $?) -eq 0 ]]
   then INTEGER=$VALUE
   else echo “ksh: $VALUE: bad number”
         exit 1
   fi

[alexvai]

Thanks lomcevak.
This is exactly what i did i Linux, but like that:

echo ${NUMBER_TO_TEST} | egrep  -q "^[-+]?([1-9][0-9]*|0)$"
	 
	 if [[ $? -eq 0 ]] then
	 	return ${__EXIT_STATUS_SUCCESS}
	 else
		return ${__EXIT_STATUS_FAILED}
	 fi