Question

In order to write to a new file , I do the following :

// some code 
...

 pfd[i][0] = open(argv[j+1],O_CREAT|O_WRONLY,0600);

Questions :

1. Is there a difference between using open or fopen ?

2. How can I use open for opening an existing file in append mode ?

Answer 1

1. open is for POSIX systems. It is not portable to other system. fopen is part of C standard, so it will work on all C implementation. I am ignoring the difference that open returns a file descriptor where fopen returns a FILE *.

2. Use O_APPEND to open for append mode.