string.c

对内存的分配、释放和使用进行检查

/*
 * (c) Copyright 1990 Conor P. Cahill (uunet!virtech!cpcahil).  
 * You may copy, distribute, and use this software as long as this
 * copyright statement is not removed.
 */

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include "malloc.h"

#ifndef lint
static
char rcs_hdr[] = "$Id: string.c,v 1.5 90/06/10 14:59:49 cpcahil Exp $";
#endif

int	malloc_checking = 0;

char *
strcat(str1,str2)
	register char	* str1;
	register char	* str2;
{
	char		* rtn;
	int	  len;

	/* 
	 * check pointers agains malloc region.  The malloc* functions
	 * will properly handle the case where a pointer does not
	 * point into malloc space.
	 */
	malloc_checking = 1;

	len = strlen(str2);
	malloc_check_str("strcat", str2);

	len += strlen(str1) + 1;
	malloc_checking = 0;

	malloc_check_data("strcat", str1, len);

	rtn = str1;

	while( *str1 )
	{
		str1++;
	}
	
	while( (*str1 = *str2) != '\0' )
	{
		str1++;
		str2++;
	}
	
	return(rtn);
}

char *
strdup(str1)
	register char	* str1;
{
	char		* malloc();
	char		* rtn;
	register char	* str2;

	malloc_check_str("strdup", str1);

	rtn = str2 = malloc((unsigned)strlen(str1)+1);

	if( rtn != (char *) 0)
	{
		while( (*str2 = *str1) != '\0' )
		{
			str1++;
			str2++;
		}
	}

	return(rtn);
}

char *
strncat(str1,str2,len)
	register char	* str1;
	register char	* str2;
	register int	  len;
{
	int 		  len1;
	int 		  len2;
	char		* rtn;

	malloc_checking = 1;

	len2 = strlen(str2) + 1;
	len1 = strlen(str1);

	malloc_checking = 0;

	malloc_check_data("strncat", str2,len2);

	if( (len+1) < len2 )
	{
		len1 += len + 1;
	}
	else
	{
		len1 += len2;
	}
	malloc_check_data("strncat", str1, len1);

	rtn = str1;

	while( *str1 )
	{
		str1++;
	}

	while( len-- && ((*str1++ = *str2++) != '\0') )
	{
	}
	
	if( ! len )
	{
		*str1 = '\0';
	}

	return(rtn);
}

int
strcmp(str1,str2)
	register char	* str1;
	register char	* str2;
{
	malloc_check_str("strcmp", str1);
	malloc_check_str("strcmp", str2);

	while( *str1 && (*str1 == *str2) )
	{
		str1++;
		str2++;
	}
	return( *str1 - *str2 );
}

int
strncmp(str1,str2,len)
	register char	* str1;
	register char	* str2;
	register int	  len;
{
	malloc_check_str("strncmp", str1);
	malloc_check_str("strncmp", str2);

	while( --len && *str1 && (*str1 == *str2) )
	{
		str1++;
		str2++;
	}
	return( *str1 - *str2 );
}

char *
strcpy(str1,str2)
	register char	* str1;
	register char	* str2;
{
	char		* rtn;
	int		  len;

	malloc_checking = 1;
	len = strlen(str2) + 1;
	malloc_checking = 0;

	malloc_check_data("strcpy", str1, len);
	malloc_check_data("strcpy", str2, len);

	rtn = str1;

	while( (*str1++ = *str2++) != '\0')
	{
	}

	return(rtn);
}

char *
strncpy(str1,str2,len)
	register char	* str1;
	register char	* str2;
	register int	  len;
{
	int		  i;
	extern int	  malloc_checking;
	char		* rtn;

	malloc_check_data("strncpy", str1, len);

	malloc_checking = 1;
	i = strlen(str2);
	malloc_checking = 0;

	if( i > len )
	{
		i = len;
	}

	malloc_check_data("strncpy", str2, i);

	rtn = str1;

	while((len-- > 0) && (*str1++ = *str2++) != '\0')
	{
	}
	while( (len-- > 0) )
	{
		*str1++ = '\0';
	}

	return(rtn);
}

int
strlen(str1)
	register char	* str1;
{
	register char	* s;

	if(! malloc_checking )
	{
		malloc_check_str("strlen", str1);
	}

	for( s = str1; *s; s++)
	{
	}

	return( s - str1 );
}

char *
strchr(str1,c)
	register char	* str1;
	register int	  c;
{
	malloc_check_str("strchr", str1);

	while( *str1 && (*str1 != (char) c) )
	{
		str1++;
	}

	if(! *str1 )
	{
		str1 = (char *) 0;
	}

	return(str1);
}

char *
strrchr(str1,c)
	register char	* str1;
	register int	  c;
{
	register char	* rtn = (char *) 0;

	malloc_check_str("strrchr", str1);

	while( *str1 )
	{
		if(*str1 == (char) c )
		{
			rtn = str1;
		}
		str1++;
	}

	return(rtn);
}

char *
index(str1,c)
	char		* str1;
	char		  c;
{
	return( strchr(str1,c) );
}

char *
rindex(str1,c)
	char		* str1;
	char		  c;
{
	return( strrchr(str1,c) );
}

char *
strpbrk(str1,str2)
	register char	* str1;
	register char	* str2;
{
	register char	* tmp;

	malloc_check_str("strpbrk", str1);
	malloc_check_str("strpbrk", str2);

	while(*str1)
	{
		for( tmp=str2; *tmp && *tmp != *str1; tmp++)
		{
		}
		if( *tmp )
		{
			break;
		}
		str1++;
	}

	if( ! *str1 )
	{
		str1 = (char *) 0;
	}

	return(str1);
}

int
strspn(str1,str2)
	register char	* str1;
	register char	* str2;
{
	register char	* tmp;
	char		* orig = str1;

	malloc_check_str("strspn", str1);
	malloc_check_str("strspn", str2);

	while(*str1)
	{
		for( tmp=str2; *tmp && *tmp != *str1; tmp++)
		{
		}
		if(! *tmp )
		{
			break;
		}
		str1++;
	}

	return( (int) (str1 - orig) );
}

int
strcspn(str1,str2)
	register char	* str1;
	register char	* str2;
{
	register char	* tmp;
	char		* orig = str1;

	malloc_check_str("strcspn", str1);
	malloc_check_str("strcspn", str2);

	while(*str1)
	{
		for( tmp=str2; *tmp && *tmp != *str1; tmp++)
		{
		}
		if( *tmp )
		{
			break;
		}
		str1++;
	}

	return( (int) (str1 - orig) );
}

/*
 * strtok() source taken from that posted to comp.lang.c by Chris Torek
 * in Jan 1990.
 */

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
 * Get next token from string s (NULL on 2nd, 3rd, etc. calls),
 * where tokens are nonempty strings separated by runs of
 * chars from delim.  Writes NULs into s to end tokens.  delim need not
 * remain constant from call to call.
 *
 * Modified by cpc: 	changed variable names to conform with naming
 *			conventions used in rest of code.  Added malloc pointer
 *			check calls.
 */
char *
strtok(str1, str2)
	char 	* str1;
	char	* str2;
{
	static char 	* last;
	char		* strtoken();

	if( str1 )
	{
		malloc_check_str("strtok", str1);
		last = str1;
	}
	malloc_check_str("strtok", str2);

	return (strtoken(&last, str2, 1));
}


/*
 * Get next token from string *stringp, where tokens are (possibly empty)
 * strings separated by characters from delim.  Tokens are separated
 * by exactly one delimiter iff the skip parameter is false; otherwise
 * they are separated by runs of characters from delim, because we
 * skip over any initial `delim' characters.
 *
 * Writes NULs into the string at *stringp to end tokens.
 * delim will usually, but need not, remain constant from call to call.
 * On return, *stringp points past the last NUL written (if there might
 * be further tokens), or is NULL (if there are definitely no more tokens).
 *
 * If *stringp is NULL, strtoken returns NULL.
 */
char *
strtoken(stringp, delim, skip)
	register char **stringp;
	register char *delim;
	int skip;
{
	register char *s;
	register char *spanp;
	register int c, sc;
	char *tok;

	if ((s = *stringp) == NULL)
		return (NULL);

	if (skip) {
		/*
		 * Skip (span) leading delimiters (s += strspn(s, delim)).
		 */
	cont:
		c = *s;
		for (spanp = delim; (sc = *spanp++) != 0;) {
			if (c == sc) {
				s++;
				goto cont;
			}
		}
		if (c == 0) {		/* no token found */
			*stringp = NULL;
			return (NULL);
		}
	}

	/*
	 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
	 * Note that delim must have one NUL; we stop if we see that, too.
	 */
	for (tok = s;;) {
		c = *s++;
		spanp = delim;
		do {
			if ((sc = *spanp++) == c) {
				if (c == 0)
					s = NULL;
				else
					s[-1] = 0;
				*stringp = s;
				return (tok);
			}
		} while (sc != 0);
	}
	/* NOTREACHED */
}

/*
 * $Log:	string.c,v $
 * Revision 1.5  90/06/10  14:59:49  cpcahil
 * Fixed a couple of bugs in strncpy & strdup
 * 
 * Revision 1.4  90/05/11  00:13:10  cpcahil
 * added copyright statment
 * 
 * Revision 1.3  90/02/24  21:50:32  cpcahil
 * lots of lint fixes
 * 
 * Revision 1.2  90/02/24  17:29:40  cpcahil
 * changed $Header to $Id so full path wouldnt be included as part of rcs 
 * id string
 * 
 * Revision 1.1  90/02/22  23:17:44  cpcahil
 * Initial revision
 * 
 */