strtok

Returns a token from a string delimited by specified characters.

char *strtok( char *string, const char *delimiters);

strtok returns a token from a string delimited by specified characters. After the first invocation, pass NULL as the value of string to get the next token.

Return Values

On the first invocation, returns a pointer to the first token found in string. Each subsequent invocation with a NULL value of string returns the next token. Returns NULL when there are no more tokens to be found.

Insert the following at the beginning of a script that uses strtok:

extern char* strtok(char *token, const char *delimiter);

Strtok must be cast to a char pointer when assigning the return value, for example:

char *token = (char *)strtok(path, separators);

Example

In this example, strtok extracts the components of a file path. Multiple calls to strtok extract each successive component from the string, path.

The separators define how a token is demarcated i.e., they are used by strtok to find breaks between the tokens. The separators here are either `\' or `.'

When using multiple calls to strtok on the same string, specify the string only on the first invocation. Subsequent calls must pass NULL as the string parameter, as we do below.

    #include <string.h> 
    char path[] = "c:\\mycomp\\lrun\\bin\\wlrun.exe";
    char separators[] = ".\\"; 
    char * token;

// Get the first token 

    token = (char *)strtok(path, separators); 
    if (!token) {
        lr_output_message ("No tokens found in string!");
        return( -1 );
    }

// While valid tokens are returned

    while (token != NULL ) { 
        lr_output_message ("%s", token );

// Get the next token

        token = (char *)strtok(NULL, separators); 
    }

Example: Output:
Action.c(18): c:
Action.c(18): mycomp
Action.c(18): lrun
Action.c(18): bin
Action.c(18): wlrun
Action.c(18): exe