Scanning for illegal characters

[Steve]

Hi,

I am having trouble scanning a text file for illegal characters. The only permitted characters are 0 - 9, + and ,

I had a case where I could not identify a . ( full stop ) by comparing a
character read using midstrt with the predefined allowable characters.

I can find the full stop using the position command but this is all.

the section of code I use is as follows

let>x=0
label>scan
let>x=x+1
readln>%file%,x,line
if>%line%=##EOF##,end
length>%line%,LL
Let>k=0
label>checkloop
let>k=k+1
if>%k%>%LL%,end
midstr>%line%,k,1,check
message>checking character %check% at position %k%
if>%check%=+,checkloop
if>%check%=%comma%,checkloop
if>%check%=0,checkloop
if>%check%=1,checkloop
if>%check%=2,checkloop
if>%check%=3,checkloop
if>%check%=4,checkloop
if>%check%=5,checkloop
if>%check%=6,checkloop
if>%check%=7,checkloop
if>%check%=8,checkloop
if>%check%=9,checkloop
label>alarm
let>flag=flag+1
goto>checkloop
label>end
Message>The scan found %flag% illegal character(s)

This routine does not find a . in the text file

Any ideas

[support]

Hi,

It does find the . - you'll see that if you step through with the debugger. You'll also see that it is equating the . to 0 in line:

if>check=0,checkloop

This is because . is mathematically equal to 0 - it is processing this particular check as a mathematical comparison. The . is the decimal place holder.

The simplest solution in your case is to add the following line to the start of your If> list :

If>check=.,alarm

Another solution is to concatenate something to both the character you're checking and the value you're checking against - that way you can be sure you know what you're comparing and be sure it's a string:

midstr>line,k,1,check
Concat>check,X
...
if>check=0X,checkloop
if>check=1X,checkloop
etc

However, if you're trying to remove certain chars from the line might want to use VBScript's Replace function, or RegExp - both discussed recently in this forum.

[steve]

many Thanks for the guidance. I wasn't aware that it was
mathematically equivalent to zero thought maybe it would do an ascii
compare or something.

Thanks again


Steve

[illegal Characters]

Hi again,

Tried your suggestions and am having problems.

I guess if . is equivalent to 0 then whatever we do with it
it will compare as the same?.

When I looked for IF>check=.,alarm it alarmed with all the 0's in the text
file also.

When I concatted an x to the check and looked for .x, etc it failed all
characters.

Any ideas

[steve]

Hi me Again,

Sorry but I mad a basic error and now have things working fine.

I followed your suggestion to the letter to concat x with check.
Unfortunatelt x is defined as a variable and so I ended up concatting
the variable but checking for X.

All works well now.

many Thanks