strftime

[cmancre]

code:

char buffer[2]={NULL,NULL};
...// time code and stuff
strftime(buffer, 2, "%M", loctime);

when i print to stdout the buffer i got trash like @, but like this:

char buffer[3]={NULL,NULL,NULL};
...// time code and stuff
strftime(buffer, 3, "%M", loctime);

the buffer is OK, i got minutes, buffer[2] still NULL
My question is, why i need that extra char (buffer[2]) for this works well?

 

[Diancecht]

Look at the man page:

http://www.opengroup.org/onlinepubs/007908799/xsh/strftime.html

It returns a terminated null byte array, you should check what the function returns.

Cheers,
Dian

 

[Salem]

> My question is, why i need that extra char (buffer[2]) for this works well?
Because all proper C strings have a \0 at the end.

So your minutes would be say "59\0" - a total of 3 chars.

> char buffer[3]={NULL,NULL,NULL};
NULL is used for pointers, which these are not.
If you want the nul character, then it's typically written as '\0'

But char buffer[3] = { 0 }; should also work just as well, since C sets all unspecified initialisers to 0 anyway.

It's a rather moot point, since you're going to initialise it anyway when you call strftime.


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