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Xref: sserve comp.unix.bsd:5919 comp.unix.large:613 comp.sys.ibm.pc.rt:1683 Path: sserve!manuel!munnari.oz.au!spool.mu.edu!sol.ctr.columbia.edu!usc!rpi!usenet.coe.montana.edu!ogicse!das-news.harvard.edu!cantaloupe.srv.cs.cmu.edu!crabapple.srv.cs.cmu.edu!andrew.cmu.edu!tm8t+ From: tm8t+@andrew.cmu.edu (Tod McQuillin) Newsgroups: comp.unix.bsd,comp.unix.large,comp.sys.ibm.pc.rt Subject: Re: strdup Message-ID: <Qemk4KW00WB98ZYN5Z@andrew.cmu.edu> Date: 1 Oct 92 05:45:58 GMT Article-I.D.: andrew.Qemk4KW00WB98ZYN5Z References: <br.pct.52.717898310@RLG.Stanford.EDU> <lckirmINNosg@spim.mti.sgi.com> Organization: Carnegie Mellon, Pittsburgh, PA Lines: 72 In-Reply-To: <lckirmINNosg@spim.mti.sgi.com> koblas@mips.com (David Koblas) writes: > Here's a copy (typed in off the cuff, so I won't say it is > guaranteed to work): > > char *strdup(char *str) > { > char *cp = (char *)malloc(strlen(str)); > return cp ? strcpy(cp, str), cp : NULL; > } > Good thing you included a dislaimer. You need to use malloc(strlen(str)+1) else the null terminator may trash the heap. Here is the 4.3BSD-reno version: (sorry about the long copyright but they insist you leave it in) /* * Copyright (c) 1988 The Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "@(#)strdup.c 5.4 (Berkeley) 2/24/91"; #endif /* LIBC_SCCS and not lint */ #include <stddef.h> #include <stdlib.h> #include <string.h> char * strdup(str) const char *str; { int len; char *copy; len = strlen(str) + 1; if (!(copy = malloc((u_int)len))) return((char *)NULL); bcopy(str, copy, len); return(copy); }