strdup.c

来自「操作系统SunOS 4.1.3版本的源码」· C语言 代码 · 共 37 行

#if !defined(lint) && defined(SCCSIDS)
static	char sccsid[] = "@(#)strdup.c 1.1 92/07/30 SMI"; /* from S5R3 1.7 */
#endif
/*	Copyright (c) 1984 AT&T	*/
/*	  All Rights Reserved  	*/

/*	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T	*/
/*	The copyright notice above does not evidence any   	*/
/*	actual or intended publication of such source code.	*/

/*LINTLIBRARY*/
/* string duplication
   returns pointer to a new string which is the duplicate of string
   pointed to by s1
   NULL is returned if new string can't be created
*/

#include <string.h>
#ifndef NULL
#define NULL	0
#endif

extern int strlen();
extern char *malloc();

char *
strdup(s1) 

   char * s1;

{  
   char * s2;

   s2 = malloc((unsigned) strlen(s1)+1) ;
   return(s2==NULL ? NULL : strcpy(s2,s1) );
}