Why ftok() always return a key value 0xFFFFFFFF ?

[jiapei100]

Hi, all:

Sorry for the naive question, but why in my testing code, ftok() always return a value 0xFFFFFFFF ??

Cheers
Pei

[abarclay]

It shouldn't even compile. You are supposed to pass a pathname and an index to ftok.

So, if I need a unique "key" for a program that will run as my username, I could use something like this:
key_t myKey;
myKey = ftok("/home/andy",1);

If I need an additional key, I could call:
myKey = ftok("/home/andy",2);

Someone else writing a program on my system could use:
myKey = ftok("/home/mary",1);

[voidpointer69]

jiapei100

Notwithstanding what abarclay has said, ftok returns -1 on failure...