If stringp is NULL,
strsep
returns NULL
and does nothing else.
If stringp is non-NULL,
strsep
finds the first token in the
stringp, where tokens are delimited by symbols
in the string delim. This token is terminated
with a \0 character (by overwriting the delimiter) and
stringp is updated to point past the token. In
case no delimiter was found, the token is taken to be the entire string
stringp, and stringp is
made NULL.
strsep
returns a pointer to the token, that is,
it returns the original value of stringp.
strsep
was introduced as a replacement for
strtok
, since the latter cannot handle empty
fields. However, strtok
conforms to
ANSI-C and hence is more portable.