Thread: Dealing with nonexistent file input

The command to activate the program would be: (C under linux)

gcc program.c
./a.out infile outfile

I'm trying to deal with the user inputting a nonexistent infile. I tried

Code:

if (infile == Null){
  printf("file not found");
  return 0;
}

A book recommended using the "error function" which would be instead of print and return, I'd write <Error("file not found")> this throws an error during compiling though. "undefined reference to error." Maybe one of those books that assumes you included a library available on the books website, or maybe a C under linux thing...

So far I either get a bunch of unreadable stuff, or a segmentation error.

maybe try this:

Code:

FILE *infile, *outfile;
char infilename[1024], outfilename[1024];

...

infile = fopen(infilename, "r");
if (infile == NULL){
    do_error_code();
}

....

got it, just added exit(0). otherwise it would throw a segmentation error due to some other part of my code.