String-Funktion

[etreu]

Gibt es in C/C++ ein ähnliches Objekt wie den StringTokenizer in Java?

Dieser teilt einen String in verschiedene Token (kleinere Ketten, die im Ausgangsstring rechts bzw. links eines bestimmten Zeichens stehen).

Bsp (aus Java):

String email = new String("name@domain");

StringTokenizer split = new StringTokenizer(email,"@");

String name=split.nextToken(); //name= "name"

String domain=split.nextToken(); //domain="domain"

[gajUli]

Gab es schon in ANSI-C, heisst strtok() oder so.

[Woodstock]

Nicht nur oder so, sie heißt definitiv so.

Hier der MSDN Text dazu:

strtok, wcstok, _mbstok

Find the next token in a string.


char *strtok( char *strToken, const char *strDelimit );


wchar_t *wcstok( wchar_t *strToken, const wchar_t *strDelimit );


unsigned char *_mbstok( unsigned char*strToken, const unsigned char *strDelimit );


Routine Required Header Compatibility 

strtok <string.h> ANSI, Win 95, Win NT 

wcstok <string.h> or <wchar.h> ANSI, Win 95, Win NT 

_mbstok <mbstring.h> Win 95, Win NT 



For additional compatibility information, see Compatibility in the Introduction.


Libraries


LIBC.LIB Single thread static library, retail version 

LIBCMT.LIB Multithread static library, retail version 

MSVCRT.LIB Import library for MSVCRT.DLL, retail version 



Return Value


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.


Parameters


strToken


String containing token(s)


strDelimit


Set of delimiter characters


Remarks


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 and _mbstok are wide-character and multibyte-character versions of strtok. The arguments and return value of wcstok are wide-character strings; those of _mbstok are multibyte-character strings. These three functions behave identically otherwise.


Generic-Text Routine Mappings


TCHAR.H Routine  _UNICODE & _MBCS Not Defined _MBCS Defined _UNICODE Defined 

_tcstok strtok  _mbstok  wcstok  



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 NULL strToken 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 function 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.


[PHP]Example


/* STRTOK.C: In this program, a loop uses strtok

 * to print all the tokens (separated by commas

 * or blanks) in the string named "string".

 */


#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



[/PHP]
[/code]

Bine

[etreu]

Danke.

--=Ich weiss warum ich Java soo seeeehr maag! =--

[Crush]

Das wurde schon öfterer durchgesprochen.

[etreu]

Kann es sein, dass die Funktion nur für statische Strings funktioniert?

Habe nämlich folgendes Problem:

Ich lese einen String ein und möchte diesen in einer anderen Funktion zerlegen.

Beim Compilieren erhalte ich die Fehlermeldung "cannot find match".

[nic_power]

Wenn Du beim Compilieren eine Fehlermeldung bekommst, muss auch irgendwo ein Syntaxfehler in Deinem Quellcode sein. Mit der Funktionsweise von strtok hat das aber nichts zu tun.

Nic