read words from file

[-EquinoX-]

So say I have the following file:

Apple
Adam
Bank
Carlos
Orange
People
Queen
Zebra


I wan't to create a getWord method that takes in a FILE* f

The example above is just a small file, but I will be using this method for a large file.. what's the best way to do this? so when I do getWord(f) I got Apple then the next time I do getWord(f) I get Adam and so on

[Doodle77]

Use fgets()

[-EquinoX-]

I was thinking to use fgets as well, but I don't know how long the string will be in each line

[Doodle77]

If you're afraid one of the "words" will be huge, you can have the program move forward until it finds the newline to get the length of the line, then malloc()s that much memory, and then goes back and calls fgets. Or you can start at a certain size and fgets that much and then realloc() if there's more, and fgets again, etc.

[-EquinoX-]

okay could you help me how to code this then?

is it like this:

char result[200];
return fgets(result, 200, file);

but using this code I am going to have to read from the disk everytime I want to get the word right? this is slow..

[Doodle77]

okay could you help me how to code this then?

is it like this:

char result[200];
return fgets(result, 200, file);

but using this code I am going to have to read from the disk everytime I want to get the word right? this is slow..

The operating system would most likely buffer the file for you.

[-EquinoX-]

okay so does my code looks good?

char* getword (FILE* fp)
{
  char result[132];
  return fgets(result, 200, fp);
}

[vart]

okay so does my code looks good?

Horrible - you are telling lies to fgets
as a result it will try to write 200 chars into buffer able to store only 132

You also return pointer to the local variable

char* getword (FILE* fp, char* result, size_t max_len)
{
  return fgets(result, max_len, fp);
}

char result[132];
char* ret = getword (fp,result, sizeof result);

and because in this case your getword is just a wrapper for fgets - you can get rid of it... Or add some functionality - for example get rid of the trailing \n character as shown in the FAG

[-EquinoX-]

okay I made a mistake in returning the local variable so I guess I should do a malloc and then return that? right

[vart]

okay I made a mistake in returning the local variable so I guess I should do a malloc and then return that? right

you can use malloc - just do not forget to free the memory after you finished with it

[-EquinoX-]

okay gotcha!

[matsp]

okay I made a mistake in returning the local variable so I guess I should do a malloc and then return that? right

You can, but as vart suggested, a local variable at the level above is much better - unless you need to malloc some memory ANYWAYS later on - then it makes sense to do all of that in that function.

--
Mats