Path: utzoo!utgpu!water!watmath!clyde!att!rutgers!mit-eddie!uw-beaver!ssc-vax!uvicctr!tholm
From: tholm@uvicctr.UUCP (Terrence W. Holm)
Newsgroups: comp.os.minix
Subject: memcpy(3) & friends
Message-ID: <496@uvicctr.UUCP>
Date: 14 Sep 88 01:15:27 GMT
Reply-To: tholm@uvicctr.UUCP (Terrence W. Holm)
Organization: University of Victoria, Victoria B.C. Canada
Lines: 282

EFTH MINIX report #40  - September 1988 -  memcpy(3) & friends


There follows an implementation of memcpy(3), memccpy(3),
memchr(3), memcmp(3) and memset(3) for MINIX. Please consider
this public domain software. "man" pages are included.

----------------------------------------------------------
echo x - memccpy.3
gres '^X' '' > memccpy.3 << '/'
XSUBROUTINES
X    memccpy(3)		- memory copy, until specified character
X
XINVOCATION
X    #include <memory.h>
X
X    char *memccpy( to, from, chr, count )
X      char *to;
X      char *from;
X      int   chr;
X      int   count;
X
XEXPLANATION
X    <count> characters are copied from the memory pointed to by
X    <from> to the memory pointed to by <to>. If the character <chr>
X    is encountered then the copy stops, after <chr> is copied.
X
XRESULTS
X    NULL : <chr> was not found.
X    o/w  : Points to the character after <chr> in <from> vector.
/
echo x - memccpy.c
gres '^X' '' > memccpy.c << '/'
X/*  memccpy(3)
X *
X *  Author: Terrence W. Holm          Sep. 1988
X */
X
X#define  NULL  (char *) 0
X
X
Xchar *memccpy( to, from, chr, count )
X  char *to;
X  char *from;
X  int   chr;
X  int   count;
X
X  {
X  while( --count >= 0 )
X    if ( (*to++ = *from++) == chr )
X	return( from );
X
X  return( NULL );
X  }
/
echo x - memchr.3
gres '^X' '' > memchr.3 << '/'
XSUBROUTINES
X    memchr(3)		- memory search
X
XINVOCATION
X    #include <memory.h>
X
X    char *memchr( vector, chr, count )
X      char *vector;
X      int   chr;
X      int   count;
X
XEXPLANATION
X    Memchr(3) looks for the character <chr> within the first
X    <count> characters of <vector>.
X
XRESULTS
X    NULL : <chr> was not found.
X    o/w  : Points to <chr> in <vector>.
X
XREFERENCES
X    strchr(3)
/
echo x - memchr.c
gres '^X' '' > memchr.c << '/'
X/*  memchr(3)
X *
X *  Author: Terrence W. Holm          Sep. 1988
X */
X
X#define  NULL  (char *) 0
X
X
Xchar *memchr( vector, chr, count )
X  char *vector;
X  int   chr;
X  int   count;
X
X  {
X  while( --count >= 0 )
X    if ( *vector++ == chr )
X	return( vector - 1 );
X
X  return( NULL );
X  }
/
echo x - memcmp.3
gres '^X' '' > memcmp.3 << '/'
XSUBROUTINES
X    memcmp(3)		- memory compare
X
XINVOCATION
X    int memcmp( vector1, vector2, count )
X      char *vector1;
X      char *vector2;
X      int   count;
X
XEXPLANATION
X    Memcmp(3) uses character comparison to determine if
X    the data pointed to by <vector1> is less, equal or
X    greater than the data pointed to by <vector2>. Up to
X    <count> characters are compared.
X
XRESULTS
X    <0 : <vector1> is less than <vector2>
X    =0 : <vector1> is equal to <vector2>
X    >0 : <vector1> is greater than <vector2>
X
XREFERENCES
X    bcmp(3), strcmp(3)
/
echo x - memcmp.c
gres '^X' '' > memcmp.c << '/'
X/*  memcmp(3)
X *
X *  Author: Terrence W. Holm          Sep. 1988
X */
X
X
Xint memcmp( vector1, vector2, count )
X  char *vector1;
X  char *vector2;
X  int   count;
X
X  {
X  register int cmp;
X
X  if ( vector1 == vector2 )
X    return( 0 );
X
X  while( --count >= 0 )
X    if ( cmp = *vector1++ - *vector2++ )
X	return( cmp );
X
X  return( 0 );
X  }
/
echo x - memcpy.3
gres '^X' '' > memcpy.3 << '/'
XSUBROUTINES
X    memcpy(3)		- memory copy
X
XINVOCATION
X    #include <memory.h>
X
X    char *memcpy( to, from, count )
X      char *to;
X      char *from;
X      int   count;
X
XEXPLANATION
X    <count> characters are copied from the memory pointed
X    to by <from> to the memory pointed to by <to>. If the
X    location <to> is within the <from> vector, then
X    the copy is done backwards to save the <from> vector
X    from being trampled.
X
XRESULTS
X    Returns <to>.
X
XREFERENCES
X    bcopy(3), strcpy(3)
/
echo x - memcpy.c
gres '^X' '' > memcpy.c << '/'
X/*  memcpy(3)
X *
X *  Author: Terrence W. Holm          Sep. 1988
X */
X
X
Xchar *memcpy( to, from, count )
X  char *to;
X  char *from;
X  int   count;
X
X  {
X  int word_count = count / sizeof(int);
X  int byte_count = count & ( sizeof(int) - 1 );
X  char *temp_to  = to;
X  
X  if ( to > from  &&  to < from + count )
X    {
X    /*  Must copy backwards  */
X    from += count;
X    to   += count;
X
X    while( --byte_count >= 0 )
X      *--to = *--from;
X
X    while( --word_count >= 0 )
X      *--((int *) to) = *--((int *) from);
X    }
X  else
X    {
X    while( --word_count >= 0 )
X      *((int *) to)++ = *((int *) from)++;
X
X    while( --byte_count >= 0 )
X      *to++ = *from++;
X    }
X
X  return( temp_to );
X  }
/
echo x - memory.h
gres '^X' '' > memory.h << '/'
X/*  memory.h  */
X
Xchar *memcpy();
Xchar *memccpy();
Xchar *memchr();
Xchar *memset();
Xint   memcmp();
/
echo x - memset.3
gres '^X' '' > memset.3 << '/'
XSUBROUTINES
X    memset(3)		- memory initialize
X
XINVOCATION
X    #include <memory.h>
X
X    char *memset( vector, chr, count )
X      char *vector;
X      int   chr;
X      int   count;
X
XEXPLANATION
X    The first <count> characters of <vector> are set to <chr>.
X
XRESULTS
X    Returns <vector>.
X
XREFERENCES
X    bzero(3)
/
echo x - memset.c
gres '^X' '' > memset.c << '/'
X/*  memset(3)
X *
X *  Author: Terrence W. Holm          Sep. 1988
X */
X
X
Xchar *memset( vector, chr, count )
X  char *vector;
X  int   chr;
X  int   count;
X
X  {
X  register char *memory = vector;
X
X  while( --count >= 0 )
X    *memory++ = chr;
X
X  return( vector );
X  }
/
----------------------------------------------------------

		Edwin L. Froese
		  uw-beaver!ubc-cs!mprg!handel!froese

		Terrence W. Holm
		  uw-beaver!uvicctr!tholm