CODEWITHSUNDEEP
pascal
FlowMafia
FlowMafia

Reputation: 1002

Program closing abruptly when file doesn't exist (IOResult file handling)

I used IOResult to verify the existence of a file, when it exists everything works fine but when the file doesn't exist the program closes abruptly.

I tried to use a try - except to catch the exception but the problem persists, perhaps I'm not using the exception properly? But not sure how should I use it.

function verifyExistence(var input:text):boolean; 
var x:word; //IOResult
var r:boolean;
    begin
        try
            {$I-}
            reset(input);
            {$I+}
            x:=IOResult;    
        except on E: EInOutError do begin
            r:=false;
            exit;
        end;
        end;

            if (x <> 0) then
                r:=false //File does not exist
            else
                r:=true; //File exists
        close(input);
        verifyExistence:=r;
    end;

procedure fopen(var path:string);
var exists:boolean;
begin
    writeln('Specify file path. Example: C:\Users\Frank\Desktop\example.txt');
    readln(path);
    assign(input,path);
    exists:=verifyExistence(input);
        if exists then begin
            //writeln('File exists');
        end
        else begin
            writeln('File does not exist');
        end;
end;

Upvotes: 1

Views: 96

Answers (1)

FlowMafia
FlowMafia

Reputation: 1002

This is how I solved the problem:

I removed the verifyExistence function, just left fopen like this:

procedure fopen(var path:string);
begin
    writeln('Specify file path. Example: C:\Users\Frank\Desktop\example.txt');
    readln(path);
    if not FileExists(path) then begin
        writeln('File does not exist'); 
        exit; 
    end;
    assign(input,path);
end;

Thanks for the help

Upvotes: 1

Related Questions