value instead of var reference to `bmove'

[unix-history] / usr / src / games / trek / utility.c

#ifndef lint
static char sccsid[] = "@(#)utility.c   4.1     (Berkeley)      %G%";
#endif not lint

/*
**  ASSORTED UTILITY ROUTINES
*/

/*
**  BLOCK MOVE
**
**      Moves a block of storage of length `l' bytes from the data
**      area pointed to by `a' to the area pointed to by `b'.
**      Returns the address of the byte following the `b' field.
**      Overflow of `b' is not tested.
*/

char *bmove(a, b, l)
char    *a, *b;
int     l;
{
       register int            n;
       register char           *p, *q;

       p = a;
       q = b;
       n = l;
       while (n--)
               *q++ = *p++;
       return (q);
}


/*
**  STRING EQUALITY TEST
**      null-terminated strings `a' and `b' are tested for
**      absolute equality.
**      returns one if equal, zero otherwise.
*/

sequal(a, b)
char    *a, *b;
{
       register char           *p, *q;

       p = a;
       q = b;
       while (*p || *q)
               if (*p++ != *q++)
                       return(0);
       return(1);
}


/*
**  STRING CONCATENATE
**
**      The strings `s1' and `s2' are concatenated and stored into
**      `s3'.  It is ok for `s1' to equal `s3', but terrible things
**      will happen if `s2' equals `s3'.  The return value is is a
**      pointer to the end of `s3' field.
*/

char *concat(s1, s2, s3)
char    *s1, *s2, *s3;
{
       register char           *p;
       register char           *q;

       p = s3;
       q = s1;
       while (*q)
               *p++ = *q++;
       q = s2;
       while (*q)
               *p++ = *q++;
       *p = 0;
       return (p);
}


/*
**  FIND STRING LENGTH
**
**      The length of string `s' (excluding the null byte which
**              terminates the string) is returned.
*/

length(s)
char    *s;
{
       register int    l;
       register char   *p;

       l = 0;
       p = s;
       while (*p++)
               l++;
       return(l);
}


/*
**  SYSTEM ERROR
*/

syserr(p0, p1, p2, p3, p4, p5)
{
       extern int      errno;

       printf("\n\07TREK SYSERR: ");
       printf(p0, p1, p2, p3, p4, p5);
       printf("\n");
       if (errno)
               printf("\tsystem error %d\n", errno);
       exit(-1);
}