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Re: simple question about bytes [message #17076 is a reply to message #16986]

Fri, 03 September 1999 00:00

R.Bauer
Messages: 1424
Registered: November 1998

Senior Member

rappold wrote:

> Hi,
>
> I want to check if a line in an ascii file starts with a number or
> character. My idea was to read the first character and convert it to
> "byte" and check if its in or out the range of '48b' and '58b'. The code
> example is :
>
> ; check for header
> header=''
> readf, lun, header
> firstchar=strmid(header,0,1)
> first_byte=byte(firstchar)
>
> no_head=0
> head_index=0
> WHILE ((first_byte LT 48b) AND (first_byte GT 57b)) DO BEGIN
> readf, lun, header ; reads next line
> head_index=head_index+1 ; counts header lines
> no_header =head_index
> ENDWHILE
> ...

You have to use the first index type e.g.

WHILE ((first_byte[0] LT 48b) AND (first_byte[0] GT 57b)) DO BEGIN

you can declare header as bytarr with one element

header=bytarr(1)
readf, lun, header
first_byte=header[0]

R.Bauer

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[Message index]

		simple question about bytes By: Gerhard D. Rappold on Thu, 02 September 1999 00:00
		Re: simple question about bytes By: R.Bauer on Fri, 03 September 1999 00:00
		Re: simple question By: Paul van Delst on Fri, 19 May 2000 00:00
		Re: simple question By: promashkin on Thu, 18 May 2000 00:00
		Re: simple question By: Paul van Delst on Thu, 18 May 2000 00:00
		Re: simple question By: Craig Markwardt on Thu, 18 May 2000 00:00

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