Re: Why can't i write to a file with this code?

s. keeling wrote:

....
nj = read(fd,buffer,100);

You're going to read 100 ints (chars?) into a buffer, and the return
value from read is used as an array subscript to terminate the buffer?
Why?

$ man 2 read
....
RETURN VALUE
On success, the number of bytes read is returned (zero

I presume that read ignores all end of lines, end of strings, etc; ie it reads upto the required number of bytes (less if EOF is encountered, for example). Thus, after reading n bytes from the file, he puts a terminating nul (\0) at the end of them.

or were you wanting him to explain?
....

buffer[nj]='\0';


However, there is a bug in what he's written:

if the read fails for any reason, it'll return -1 and so he'll be splatting a nul over the byte *BEFORE* the buffer - he may be lucky in that it does no damage, but then again, he may not...

.

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