open or fopen?

open or fopen?

[Eric Fisher]

hi,
There is a question about file operation functions used in gcc source
code. I can't figure out why sometimes we use open function such as
load_specs in gcc.c,
static char *
load_specs (const char *filename)
{
  int desc;
  ...
  /* Open and stat the file.  */
  desc = open (filename, O_RDONLY, 0);
  ...
}
why not fopen?

Thanks

Re: open or fopen?

[Ingo Krabbe]

Am Donnerstag, 18. Mai 2006 10:15 schrieb Eric Fisher:
> hi,
> There is a question about file operation functions used in gcc source
> code. I can't figure out why sometimes we use open function such as
> load_specs in gcc.c,
> static char *
> load_specs (const char *filename)
> {
>   int desc;
>   ...
>   /* Open and stat the file.  */
>   desc = open (filename, O_RDONLY, 0);
>   ...
> }
> why not fopen?
>
> Thanks

Sometimes it is easier to use open above fopen, when you need binary 
transfers, though I doubt the correctness of this statement for the specs 
file.  But this might be a quite historic piece of code where we couldn't be 
sure about the libc implementation that provides fopen.

Note that open should be available as a system call where fopen isn't 
available, which is a library call (embedded systems ?!)