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colt1954 · Joined: 21 Dec 2010 Posts: 81

I am trying to read a data file, some lines I need to miss out etc, the programe on execute comes back with error 52 invalid character in field with error message below. But it does not give the code line number that I recognize where its complaining, I did try the step into approach but it just comes up with similar error codes etc plus other listing that that I do not understand etc...

00401000 MAIN [+179d]

Any ideas how to better get to the bottom of such problems...if only it would tell me the line number the read error occurs, like it does when the compiler complains.

brucebowler · Guest

A semi painful/brute force way would be to write out the data after you read it. If there are multiple places you read the file, it also helps to write out some indication of which read it is.

mecej4 · Joined: 31 Oct 2006 Posts: 1886

To obtain line number information upon program abort, you have to enable it by compiling and linking with /debug or other debug options. You can also set up /debug as a default option, if you wish.

Please read the documentation in the help files.

colt1954 · Joined: 21 Dec 2010 Posts: 81

colt1954 · Joined: 21 Dec 2010 Posts: 81

brucebowler · Guest

sparge · Joined: 11 Apr 2005 Posts: 371

JohnHorspool · Joined: 26 Sep 2005 Posts: 270 Location: Gloucestershire UK

You could try reading each line of data as character string and then do an internal read on the string, writing each string to the screen before the internal read.
_________________
John Horspool
Roshaz Software Ltd.
Gloucestershire

LitusSaxonicum · Posted: Sat Mar 26, 2011 10:40 am Post subject:

Bruce may well be right that it is the very first read that is the problem.

Quite possibly, your data file contains an invisible character that is invalid in the context. The first time I faced this was getting on for 30 years ago, when my word-processor (Wordstar) had a "non-document" mode (OK for Fortran) and a "document" mode that wasn't.

What you have to do is to read that line of data into (say) a CHARACTER array or variable. That must work, as all characters are valid in this format. If you print it out, you will just get an invisible character again - you'll never see it. However, if you print the numerical value of each character, getting it by using ICHAR, then you will be able to print out the number.

From memory, the invisible characters are most of the ones numbered less than 32. From memory I can't remember if 127 or greater is a problem too.

If your datafile was written unformatted and you try to read it with formats, you will also be in trouble. It is possible you have the problem right the way through your file, or it could be simply one character at the start, or somewhere in between.

Eddie