pSOSystem System Calls - Read

strtok pREPC+ System Calls
strtok Searches a string for tokens.
#include
char *strtok(
char *s1, /* search string */
const char *s2 /* delimiter(s) */
)
Description
Arguments
A series of calls to the strtok() function breaks a string (s1) into a sequence of
tokens, each of which is delimited by a character in a second string (s2). A token is
a sequence of one or more characters. The first call to strtok() has s1 as its first
argument, and is followed by calls with a null pointer as their first argument.
On the first call to strtok(), s1 is passed as a pointer to the string to be searched,
and s2 is passed as a pointer to the string that contains the delimiters. The first call
searches for the first character in s1 that is not found in the delimiter set. If such a
character is found, it is the start of the first token. If the first call fails to find a
character that is not a delimiter, there are no tokens, and a null pointer is returned.
The function then continues the search of s1 for a character that is contained in the
delimiter set. If no such character is located, the current token extends to the end of
s1, and subsequent calls to the function return a null pointer. If a delimiter is
located, a null character that terminates the current token overwrites the delimiter.
The function saves the pointer to the character that follows. This is where the next
search for a token starts.
In subsequent calls, the first argument should be a null pointer. The search for the
next token begins from the saved pointer and behaves as described in the preceding
paragraph.
The search string s2 can be changed between calls. This allows strtok() to
continue to parse the string with a different set of delimiters.
s1 Points to the string to be searched.
s2 Points to the string containing token delimiters.
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