A `token' is a nonempty string of characters not occurring in the string delim, followed by 0 or by a character occurring in delim.
The strtok() function can be used to parse the string s into tokens. The first call to strtok() should have s as its first argument. Subsequent calls should have the first argument set to NULL. Each call returns a pointer to the next token, or NULL when no more tokens are found.
If a token ends with a delimiter, this delimiting character is overwritten with a 0 and a pointer to the next character is saved for the next call to strtok(). The delimiter string delim may be different for each call.
Never use these functions. If you do, note that:
These functions modify their first argument.
The identity of the delimiting character is lost.
These functions cannot be used on constant strings.
SVID 3, POSIX, BSD 4.3, ISO 9899