175 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			175 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
| /*-
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|  * Copyright (c) 1991 The Regents of the University of California.
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|  * All rights reserved.
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|  *
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|  * This code is derived from software contributed to Berkeley by
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|  * Kenneth Almquist.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  * 2. Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  * 3. All advertising materials mentioning features or use of this software
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|  *    must display the following acknowledgement:
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|  *	This product includes software developed by the University of
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|  *	California, Berkeley and its contributors.
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|  * 4. Neither the name of the University nor the names of its contributors
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|  *    may be used to endorse or promote products derived from this software
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|  *    without specific prior written permission.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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|  * SUCH DAMAGE.
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|  */
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| 
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| #ifndef lint
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| static char sccsid[] = "@(#)mystring.c	5.1 (Berkeley) 3/7/91";
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| #endif /* not lint */
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| 
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| /*
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|  * String functions.
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|  *
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|  *	equal(s1, s2)		Return true if strings are equal.
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|  *	scopy(from, to)		Copy a string.
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|  *	scopyn(from, to, n)	Like scopy, but checks for overflow.
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|  *	strchr(s, c)		Find first occurance of c in s.
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|  *	bcopy(from, to, n)	Copy a block of memory.
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|  *	number(s)		Convert a string of digits to an integer.
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|  *	is_number(s)		Return true if s is a string of digits.
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|  */
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| 
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| #include "shell.h"
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| #include "syntax.h"
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| #include "error.h"
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| #include "mystring.h"
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| 
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| 
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| char nullstr[1];		/* zero length string */
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| 
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| 
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| /*
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|  * scopyn - copy a string from "from" to "to", truncating the string
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|  *		if necessary.  "To" is always nul terminated, even if
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|  *		truncation is performed.  "Size" is the size of "to".
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|  */
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| 
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| void
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| scopyn(from, to, size)
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| 	register char const *from;
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| 	register char *to;
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| 	register int size;
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| 	{
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| 
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| 	while (--size > 0) {
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| 		if ((*to++ = *from++) == '\0')
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| 			return;
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| 	}
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| 	*to = '\0';
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| }
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| 
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| 
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| /*
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|  * strchr - find first occurrence of a character in a string.
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|  */
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| 
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| #ifndef SYS5
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| char *
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| mystrchr(s, charwanted)
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| 	char const *s;
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| 	register char charwanted;
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| 	{
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| 	register char const *scan;
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| 
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| 	/*
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| 	 * The odd placement of the two tests is so NUL is findable.
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| 	 */
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| 	for (scan = s ; *scan != charwanted ; )	/* ++ moved down for opt. */
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| 		if (*scan++ == '\0')
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| 			return NULL;
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| 	return (char *)scan;
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| }
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| #endif
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| 
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| 
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| 
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| /*
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|  * bcopy - copy bytes
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|  *
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|  * This routine was derived from code by Henry Spencer.
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|  */
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| 
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| void
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| mybcopy(src, dst, length)
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| 	pointer dst;
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| 	const pointer src;
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| 	register int length;
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| 	{
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| 	register char *d = dst;
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| 	register char *s = src;
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| 
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| 	while (--length >= 0)
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| 		*d++ = *s++;
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| }
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| 
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| 
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| /*
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|  * prefix -- see if pfx is a prefix of string.
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|  */
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| 
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| int
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| prefix(pfx, string)
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| 	register char const *pfx;
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| 	register char const *string;
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| 	{
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| 	while (*pfx) {
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| 		if (*pfx++ != *string++)
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| 			return 0;
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| 	}
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| 	return 1;
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| }
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| 
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| 
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| /*
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|  * Convert a string of digits to an integer, printing an error message on
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|  * failure.
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|  */
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| 
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| int
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| number(s)
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| 	const char *s;
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| 	{
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| 
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| 	if (! is_number(s))
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| 		error2("Illegal number", (char *)s);
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| 	return atoi(s);
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| }
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| 
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| 
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| 
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| /*
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|  * Check for a valid number.  This should be elsewhere.
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|  */
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| 
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| int
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| is_number(p)
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| 	register const char *p;
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| 	{
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| 	do {
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| 		if (! is_digit(*p))
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| 			return 0;
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| 	} while (*++p != '\0');
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| 	return 1;
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| }
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