ms-dos-3.3/SRC/LIBC/ERRTST.C

#include "types.h"
#include "dpb.h"
#include <dos.h>

/*  #define KANJI   TRUE	*/

/* return FALSE if drive is valid AND the path is not a prefix of a non-root
 * current directory.
 */
char fPathErr(p)
char *p ;
{
	char buf[MAXARG] ;
	int d ;
#ifdef KANJI
	char *p1;
#endif

	if (p[1] == ':')
		d = *p-'A'+1 ;
	else
		d = 0 ;

	if (curdir(buf, d) == -1)	/* drive is invalid => error	   */
		return(TRUE) ;

	if (strlen(buf) == 3)		/* current directory is root => OK */
		return(FALSE) ;

	if (strpre(p, buf)) {
#ifdef KANJI
		p1 = p;
		while (*p1 != NULL) {
		    if(testkanj(*p1 & 0xFF))
			p1 += 2 ;
		    else
			if((*p1++ == '\\') && (*p1 == NULL))
				return(TRUE) ;
		}
#else
		if (p[strlen(p)-1] == '\\') /* prefix matched, prefix had...*/
			return(TRUE) ;	    /* ...trailing / => valid ...   */
					   /* ...prefix => ERROR	   */
#endif
		d = buf[strlen(p)] ;
		if (d == 0 || d == '\\') /* prefix matched,... */
			return(TRUE) ;	    /* ...prefix had no trailing /, */
					   /* ...next char was / => ...    */
					   /* ...valid prefix => ERROR	   */
	} ;

	return(FALSE) ;    /* drive letter good and not valid prefix => OK  */
}


strpre(pre, tot)
	char	*pre;
	char	*tot;
{
	return(!strncmp(pre, tot, strlen(pre)));
}



Fatal(p)
char *p ;
{
	printf("%s\n", p) ;
	exit(1) ;
}




ffirst(pb, attr, pfbuf)
char *pb ;
int attr ;
struct findType *pfbuf ;
{
	union REGS regs ;

	/* set DMA to point to buffer */

	regs.h.ah = 0x1A ;
	regs.x.dx = (unsigned) pfbuf ;
	intdos (&regs, &regs) ;

	/* perform system call */

	regs.h.ah = 0x4E ;
	regs.x.cx = attr ;
	regs.x.dx = (unsigned) pb ;
	intdos (&regs, &regs) ;

	return (regs.x.cflag ? -1 : 0) ;
}

fnext (pfbuf)
struct findType *pfbuf;
{
    union REGS regs;

    /* set DMA to point to buffer */
    regs.h.ah = 0x1A;
    regs.x.dx = (unsigned) pfbuf;
    intdos (&regs, &regs);
    /* perform system call */
    regs.h.ah = 0x4F;
    intdos (&regs, &regs);
    return (regs.x.cflag ? -1 : 0) ;
}


char *strbscan(str, class)
char *str ;
char *class ;
{
	char *p ;
	char *strpbrk() ;

	p = strpbrk(str, class) ;
	return((p == NULL) ? (str + strlen(str)) : p) ;
}





/* curdir.c - return text of current directory for a particular drive */


curdir (dst, drive)
char *dst ;
int drive ;
{
    union REGS regs ;

    *dst++ = PathChr ;
    regs.h.ah = 0x47 ;
    regs.h.dl = drive ;
    regs.x.si = (unsigned) dst ;
    intdos (&regs, &regs) ;
    return(regs.x.cflag ? -1 : 0) ;
}




/*
   rootpath
*/

/*** rootpath  --  convert a pathname argument to root based cannonical form
 *
 * rootpath determines the current directory, appends the path argument (which
 * may affect which disk the current directory is relative to), and qualifies
 * "." and ".." references.  The result is a complete, simple, path name with
 * drive specifier.
 *
 * If the relative path the user specifies does not include a drive spec., the
 * default drive will be used as the base.  (The default drive will never be
 * changed.)
 *
 *  entry: relpath  -- pointer to the pathname to be expanded
 *	   fullpath -- must point to a working buffer, see warning
 *   exit: fullpath -- the full path which results
 * return: true if an error occurs, false otherwise
 *
 * calls: curdir, getdrv
 *
 * warning: fullpath must point to a working buffer large enough to hold the
 *	    longest possible relative path argument plus the longest possible
 *	    current directory path.
 *
 */
int rootpath(relpath, fullpath)
char *relpath ;
char *fullpath ;
{
	int drivenum ;
	char tempchar, getdrv() ;
	register char *lead, *follow ;
	char *p1, *p2;


	/* extract drive spec */
	drivenum = getdrv() ;
	if ((*relpath != NULL) && (relpath[1] == COLON)) {
		drivenum = toupper(*relpath) - 'A' ;
		relpath += 2 ;
	}
	fullpath[0] = (char) ('A' + drivenum) ;
	fullpath[1] = COLON ;

	/* append relpath to fullpath/base */
	if (*relpath == PathChr) {
		/* relpath starts at base */
		strcpy(fullpath+2, relpath) ;
	}
	else {
		/* must get base path first */
		if (curdir(fullpath+2, drivenum+1))
			return(TRUE) ;			/* terrible error */
		if ((*relpath != ASCNULL) && (strlen(fullpath) > 3))
			strcat(fullpath, "\\") ;
		strcat(fullpath, relpath) ;
	}


	/* convert path to cannonical form */
	lead = fullpath ;
	while(*lead != ASCNULL) {
		/* mark next path segment */
		follow = lead ;
		lead = (char *) strpbrk(follow+1, "\\") ;
		if (lead == NULL)
			lead = fullpath + strlen(fullpath) ;
		tempchar = *lead ;
		if (tempchar == PathChr)
			tempchar = BACKSLASH ;	 /* make breaks uniform */
		*lead = ASCNULL ;

		/* "." segment? */
		if (strcmp(follow+1, ".") == 0) {
			*lead = tempchar ;
			strcpy(follow, lead) ;	/* remove "." segment */
			lead = follow ;
		}

		/* ".." segment? */
		else if (strcmp(follow+1, "..") == 0) {
			*lead = tempchar ;
			tempchar = *follow ;
			*follow = NULL ;
			p2 = fullpath - 1 ;
			while(*(p2=strbscan(p1=p2+1,"\\")) != NULL) ;
			/* p1 now points to the start of the previous element */
			*follow = tempchar ;
			if(p1 == fullpath)
			    return(TRUE) ;	/* tried to .. the root */
			follow = p1 - 1 ;	/* follow points to path sep */
			strcpy(follow, lead) ;	       /* remove ".." segment */
			lead = follow ;
		}

		/* normal segment */
		else
			*lead = tempchar ;
	}
	if (strlen(fullpath) == 2)  /* 'D:' or some such */
		strcat(fullpath, "\\") ;

	/* shift to upper case */
	strupr(fullpath) ;

	return(FALSE) ;
}


/* getdrv - return current drive as a character */


char getdrv()
{
    union REGS regs ;

    regs.h.ah = CURDISK ;		/* Function 0x19		   */
    intdos (&regs, &regs) ;
    return(regs.h.al) ;
}