Help with reading text file in GFA

[Kirkman]

I'm trying to write a simple GFA Basic program using v3.5 in Hatari.

The purpose of the program is to call Larry Mears' new Instant Graphics TTP program, while passing the name of an artwork file as a parameter to the TTP.

I wrote the following code, based on old posts I read here, and it works great when compiled:

Code: Select all

file$="A:\IGNITE.IG"
c$=CHR$(LEN(file$))+file$
~SHEL_WRITE(1,1,0,c$,"A:\IGX1220.TTP")

Now, I want to revise this program so that instead of using a hard-coded artwork filename, the program will instead read the filename from a text file called IGX.INF.

Here's the revised code I wrote:

Code: Select all

file$=""
CLOSE #1
OPEN "I",#1,"A:\IGX.INF"
WHILE EOF(#1)=0
  LINE INPUT #1,buffer$
  file$=file$+buffer$
WEND
CLOSE #1
IF file$<>""
  c$=CHR$(LEN(file$))+file$
  ~SHEL_WRITE(1,1,0,c$,"A:\IGX1220.TTP")
ENDIF

Unfortunately, when I compile it and try to run the .PRG, it gives me an Error 026.

Clearly there's a problem reading the text file. It seems like a really straightforward task. Can anyone tell me what I'm doing wrong? How can I fix this?

[DarkLord]

I'd contact Lonny (LP). He maintains the GFA stuff and is pretty much expert level
awesomeness when it comes to GFA.

[charles]

eof reached =026

is the file being loaded above 32768 bytes?

[charles]

im no role model gfa expert
but why is file length only required to be 1 eight bit character?

[Kirkman]

eof reached =026

is the file being loaded above 32768 bytes?

No, it's only 12 bytes.

but why is file length only required to be 1 eight bit character?

I wasn't totally sure why the CHR/LEN stuff was necessary, but it *does* work. It came from a reply to an old post written by LP.

After a bit more research, I found this passage in the GFA Basic Compendium which seems to explain it:

... The first character of the command line contains it's length (maximum 127). This is known as a Pascal style string. ...

[czietz]

My guess is that you didn't terminate the (last) line in "A:\IGX.INF" with a newline (CR/LF). LINE INPUT reads until it finds a newline and will hit EOF if the line is not terminated.

PS: I wonder why you even read multiple lines from IGX.INF in a WHILE loop.

[ThorstenOtto]

The error codes can be looked up in the GFA-Basic compendium, for example here: http://tho-otto.de/hypview/hypview.cgi? ... &index=480

I also wonder why you read lines in a loop when you need only a single filename.

Another problem could be the initial close #1 (don't know how it behaves when the file channel was not opened before)

[charles]

heres my working of it all

Code: Select all

'
' CLOSE #1
'
' a$="a:\ignite.ig"
'
' OPEN "o",#1,"d:\igx.inf"
' a%=LEN(a$)
' BPUT #1,V:a$,a%
' CLOSE #1
'
a$=""
'
OPEN "i",#1,"A:\igx.inf"
a%=LOF(#1)
a$=SPACE$(a%)
BGET #1,V:a$,a%
CLOSE #1
'
PRINT a$
'
f$=UPPER$(a$)
c$=CHR$(LEN(f$))+f$
~SHEL_WRITE(1,1,0,c$,UPPER$("a:\igx1220.ttp"))
'
END

[charles]

I see now
yes len of filename
not len of file

: )

[charles]

simpler method

Code: Select all

SAVE "d:\igshel.gfa"
LIST "d:\igshel.lst"
'
CLOSE #1
'
a$="A:\igx.inf"
'
OPEN "o",#1,a$
PRINT #1,"a:\ignite.ig"
CLOSE #1
'
IF EXIST(a$)
OPEN "i",#1,a$
INPUT #1,a$
CLOSE #1
'
c$=CHR$(LEN(a$))+a$
~SHEL_WRITE(1,1,0,c$,UPPER$("a:\igx1220.ttp"))
ENDIF
'
END

[Kirkman]

Thanks everyone for your questions and suggestions. You all steered me to something that works!

Here's where I landed. I revised it to allow the .INF file to include multiple filenames, one per line, and the program will pass all the filenames as a space-delimited list to the IGX TTP (which supports display multiple files).

Code: Select all

ttp_file$="A:\IGX1220.TTP"
inf_file$="A:\IGX.INF"
ig_files$=""
'
CLOSE #1
'
IF EXIST(inf_file$)
  OPEN "I",#1,inf_file$
  '
  WHILE EOF(#1)=0
    buffer=INP(#1)
    IF buffer>31 AND buffer<127
      ig_files$=ig_files$+CHR$(buffer)
    ELSE
      IF buffer=10
        ig_files$=ig_files$+" "
      ENDIF
    ENDIF
  WEND
  '
  ' PRINT ig_files$
  CLOSE #1
  '
  ig_files$=TRIM$(ig_files$)
  '
  IF ig_files$<>""
    c$=CHR$(LEN(ig_files$))+ig_files$
    ~SHEL_WRITE(1,1,0,c$,ttp_file$)
  ENDIF
ENDIF