fln_fix.c

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/*
**  FLN_FIX.C
**
**  Original Copyright 1988-1991 by Bob Stout as part of
**  the MicroFirm Function Library (MFL)
**
**  The user is granted a free limited license to use this source file
**  to create royalty-free programs, subject to the terms of the
**  license restrictions specified in the LICENSE.MFL file.
*/

#include <stdio.h>
#include <string.h>
#include <dos.h>
#include <io.h>
#include "sniptype.h"
#include "filnames.h"

/****************************************************************/
/*                                                              */
/*  Function to `crunch' dot directories and check for          */
/*  DOS-valid path strings. Drive specifiers in the path        */
/*  ignored.                                                    */
/*                                                              */
/****************************************************************/

char *fln_fix(char *path)
{
      Boolean_T dir_flag = False_, root_flag = False_;
      char *r, *p, *q, *s;

      if (path)
            strupr(path);

      /* Ignore leading drive specs   */

      if (NULL == (r = strrchr(path, ':')))
            r = path;
      else  ++r;

      unix2dos(r);                      /* Convert Unix to DOS style    */

      while ('\\' == *r)                /* Ignore leading backslashes   */
      {
            if ('\\' == r[1])
                  strcpy(r, &r[1]);
            else
            {
                  root_flag = True_;
                  ++r;
            }
      }

      p = r;                            /* Change "\\" to "\"           */
      while (NULL != (p = strchr(p, '\\')))
      {
            if ('\\' ==  p[1])
                  strcpy(p, &p[1]);
            else  ++p;
      }

      while ('.' == *r)                 /* Scrunch leading ".\"         */
      {
            if ('.' == r[1])
            {
                  /* Ignore leading ".."                                */

                  for (p = (r += 2); *p && (*p != '\\'); ++p)
                        ;
            }
            else
            {
                  for (p = r + 1 ;*p && (*p != '\\'); ++p)
                        ;
            }
            strcpy(r, p + ((*p) ? 1 : 0));
      }

      while ('\\' == LAST_CHAR(path))   /* Strip trailing backslash     */
      {
            dir_flag = True_;
            LAST_CHAR(path) = '\0';
      }

      s = r;

      /* Look for "\." in path        */

      while (NULL != (p = strstr(s, "\\.")))
      {
            if ('.' == p[2])
            {
                  /* Execute this section if ".." found                 */

                  q = p - 1;
                  while (q > r)           /* Backup one level           */
                  {
                        if (*q == '\\')
                              break;
                        --q;
                  }
                  if (q > r)
                  {
                        strcpy(q, p + 3);
                        s = q;
                  }
                  else if ('.' != *q)
                  {
                        strcpy(q + ((*q == '\\') ? 1 : 0),
                              p + 3 + ((*(p + 3)) ? 1 : 0));
                        s = q;
                  }
                  else  s = ++p;

            }
            else
            {
                  /* Execute this section if "." found                  */

                  q = p + 2;
                  for ( ;*q && (*q != '\\'); ++q)
                        ;
                  strcpy (p, q);
            }
      }

      if (root_flag)  /* Embedded ".." could have bubbled up to root  */
      {
            for (p = r; *p && ('.' == *p || '\\' == *p); ++p)
                  ;
            if (r != p)
                  strcpy(r, p);
      }

      if (dir_flag)
            strcat(path, "\\");
      return path;
}