feature RETVAL for LOAD$

[rikky]

Hello,

I have this program:

PRINT (LOAD$("test.txt"))
It gives:

Runtime error: function 'LOAD$/BLOAD' at line 1 in 'test.bac': Error opening file: No such file or directory
echo $?
gives : 0

Also in BaCon
END RETVAL gives : 0

LOAD$ doesn't give a RETVAL that can be catched by ba(sh)

This isn't rely important of course, but it would be nice.
It can be worked around easily:

IF FILEEXISTS("test.txt") THEN 
  EPRINT "Error opening file: " & BASENAME$(TOKEN$(ARGUMENT$,1)) & " file doesn't exist"
  END 1
ENDIF
 Rik.

EDIT: but then the other way around : IF NOT(FILEEXISTS("

[Pjot]

Hi rikky,

A program should return the actual ERROR value to the shell when an error occurs. This didn't work for all circumstances and is now fixed (latest in fossil).

Apart from this, note that you can ignore errors altogether by setting "OPTION ERROR FALSE" in the beginning of your program. The program will proceed as if nothing has happened.

Also you can set your own error callback which allows a self-defined exit code (0-255). For example:

OPTION ERROR FALSE
CATCH ERROR help

SUB help(c$, f$, no)
   PRINT "Error is: ", ERR$(ERROR), " in function ", c$, " in file '", f$, "' at line ", no
   END 123
END SUB

a$ = LOAD$("not-existing-file.txt")


In this example, the BASH "$?" command returns 123.

HTH
Peter

[rikky]

I see,
I never understood this thing, for I could not grasp where the c$ f$ and no were coming from.
But I guess they are generated by the CATCH statement.

Aha.

Thanks.

 Rik.

[bigbass]

Hello Rik

you wanted a
feature RETVAL for LOAD$

we can make a homemade MACRO to simulate that idea (sort of)

but once again this type of thing is not even close to official bacon code
it could be useful when you need to extend a built in command or function

we also get the low level error reported correctly



ALIAS perror TO FALT
ALIAS fclose TO ECLOSE
DECLARE myfile TYPE FILE*

'---ELOAD means error test on load
'---ELOAD with a return value test defaults to read only "r"
DEF FN ELOAD(a) = fopen(a,"r")

 
   myfile = ELOAD("nada.bac")
 
   IF myfile == NULL  THEN
  FALT("You got this error ")
  END 1
   ELSE
 
  WHILE NOT(ENDFILE(myfile))
 READLN txt$ FROM myfile
 PRINT txt$
  WEND
  ECLOSE(myfile)
   END IF


[rikky]

Thanks Bigbass,

For now however I tend to go wit the Pjotr solution.
For it's the most simple one to remember.

OPTION ERROR FALSE

CATCH ERROR help

SUB help(function_name$, filename$, lineno)
   PRINT ERR$(ERROR), " in function ", function_name$, " in file '", filename$, "' at line ", lineno
   END 123
END SUB

PRINT LOAD$("nops")
 Rik.