Converting a string to integer in Korn shell 2

[rogers42]

Hi Folks,

I need help to convert a string to integer so I can manipulate the numbers

My Korn shell script is as follows

typeset -i today=`date +%d`
print $today
yesterday=$today-1
print $yesterday

I get "21 -1" for yesterday

Thanks in advance

rogers42

 

[p5wizard]

See the [tt]let[/tt] builtin command in the [tt]ksh[/tt] man page.

[tt]let yesterday=today-1

(( yesterday=today-1 ))[/tt]

What you are doing is just string concatenation...



HTH,

p5wizard

 

[SamBones]

In the Korn shell, "[tt]typeset[/tt]" can also force a variable to be an integer.

#!/bin/ksh

typeset -i TODAY=$(date '+%d')
typeset -i YESTERDAY

(( YESTERDAY = TODAY - 1 ))

print $YESTERDAY

 

[p5wizard]

In the Korn shell, "typeset" can also force a variable to be an integer.

Granted, but you still need to do the arithmetic with [tt]let[/tt] or the [tt](( ))[/tt] equivalent for [tt]let[/tt] ...

HTH,

p5wizard

 

[SamBones]

Yup, I wasn't contradicting what you said, just adding to it.

Of course after making my post, I noticed that he had "typeset -i" in his example already, so I was probably stating what he already knew.

Sorry!

 

[PHV]

Another way in ksh:
yesterday=$(($(date +%d)-1))

Hope This Helps, PH.
FAQ219-2884
FAQ181-2886

 

[dstxaix]

Would it work for the first of the month?

 

[PHV]

Would it work for the first of the month?
No.
Have a look here:
faq822-4802

Hope This Helps, PH.
FAQ219-2884
FAQ181-2886