strtok, wcstok (Windows CE 5.0)

Article
09/14/2012

Developing an Application > Microsoft C Run-time Library for Windows CE > Run-time Library Reference

Find the next token in a string.

char *strtok( char *strToken, constchar *strDelimit );wchar_t *wcstok( wchar_t *strToken, const wchar_t *strDelimit);

Parameters

strToken
String containing token(s).
strDelimit
Set of delimiter characters.

Return Values

All of these functions return a pointer to the next token found in strToken. They return NULL when no more tokens are found. Each call modifies strToken by substituting a NULL character for each delimiter that is encountered.

Remarks

These functions are supported by all versions of the C run-time libraries.

The strtok function finds the next token in strToken. The set of characters in strDelimit specifies possible delimiters of the token to be found in strToken on the current call. wcstok is the wide-character version of strtok. The arguments and return value of wcstok are wide-character strings. These two functions behave identically otherwise.

The following table shows generic-text routine mappings for this function.

TCHAR.H Routine	_UNICODE Defined
_tcstok	wcstok

For more information about TCHAR.H routines, see Generic Text Mappings.

On the first call to strtok, the function skips leading delimiters and returns a pointer to the first token in strToken, terminating the token with a null character. More tokens can be broken out of the remainder of strToken by a series of calls to strtok.

Each call to strtok modifies strToken by inserting a null character after the token returned by that call. To read the next token from strToken, call strtok with a NULL value for the strToken argument.

The NULLstrToken argument causes strtok to search for the next token in the modified strToken. The strDelimit argument can take any value from one call to the next so that the set of delimiters may vary.

**Warning **Each of these functions uses a static variable for parsing the string into tokens. If multiple or simultaneous calls are made to the same function, a high potential for data corruption and inaccurate results exists.

Therefore, do not attempt to call the same function simultaneously for different strings and be aware of calling one of these functions from within a loop where another routine may be called that uses the same function. However, calling this function simultaneously from multiple threads does not have undesirable effects.

Example

Description

In this program, a loop uses strtok to print all the tokens (separated by commas or blanks) in the string named "string".

Code

#include <string.h>
#include <stdio.h>

char string[] = "A string\tof ,,tokens\nand some  more tokens";
char seps[]   = " ,\t\n";
char *token;

void main( void )
{
   printf( "%s\n\nTokens:\n", string );
   /* Establish string and get the first token: */
   token = strtok( string, seps );
   while( token != NULL )
   {
      /* While there are tokens in "string" */
      printf( " %s\n", token );
      /* Get next token: */
      token = strtok( NULL, seps );
   }
}
// Output
A string   of ,,tokens
and some  more tokens

Tokens:
 A
 string
 of
 tokens
 and
 some
 more
 tokens

Requirements

OS Versions: Windows CE 2.0 and later.

Header: stdio.h, string.h.

Link Library: coredll.dll.