home *** CD-ROM | disk | FTP | other *** search
/ The C Users' Group Library 1994 August / wc-cdrom-cusersgrouplibrary-1994-08.iso / listings / v_01_02 / 1n02055b < prev    next >
Text File  |  1990-07-09  |  4KB  |  137 lines
  1. /*
  2. **  Listing 3 - 
  3. */
  4.  
  5. #include <stdio.h>
  6. #include <string.h>
  7. #include <dos.h>
  8. #include <io.h>
  9.  
  10. #define LAST_CHAR(string) (((char *)string)[strlen(string)-1])
  11.  
  12. typedef enum {ERROR = -1, FALSE, TRUE} LOGICAL;
  13.  
  14. char *unix2dos(char *path);
  15.  
  16. /*************************************************************/
  17. /*                                                           */
  18. /*  Function to `crunch' dot directories and check for       */
  19. /*  DOS-valid path strings. Drive specifiers in the path     */
  20. /*  ignored.                                                 */
  21. /*                                                           */
  22. /*************************************************************/
  23.  
  24. char *fln_fix(char *path)
  25. {
  26.         LOGICAL dir_flag = FALSE, root_flag = FALSE;
  27.         char *r, *p, *q, *s;
  28.  
  29.         if (path)
  30.                 strupr(path);
  31.  
  32.         /* Ignore leading drive specs   */
  33.  
  34.         if (NULL == (r = strrchr(path, ':')))
  35.                 r = path;
  36.         else    ++r;
  37.  
  38.         unix2dos(r);                    /* Convert Unix to DOS style */
  39.  
  40.         while ('\\' == *r)             /* Ignore leading backslashes */
  41.         {
  42.         if ('\\' == r[1])
  43.             strcpy(r, &r[1]);
  44.         else
  45.         {
  46.             root_flag = TRUE;
  47.             ++r;
  48.         }
  49.         }
  50.  
  51.         p = r;                          /* Change "\\" to "\"        */
  52.         while (NULL != (p = strchr(p, '\\')))
  53.         {
  54.                 if ('\\' ==  p[1])
  55.                         strcpy(p, &p[1]);
  56.                 else    ++p;
  57.         }
  58.  
  59.         while ('.' == *r)               /* Scrunch leading ".\"      */
  60.         {
  61.                 if ('.' == r[1])
  62.                 {
  63.                         /* Ignore leading ".."                       */
  64.  
  65.                         for (p = (r += 2); *p && (*p != '\\'); ++p)
  66.                                 ;
  67.                 }
  68.                 else
  69.                 {
  70.                         for (p = r + 1 ;*p && (*p != '\\'); ++p)
  71.                                 ;
  72.                 }
  73.         strcpy(r, p + ((*p) ? 1 : 0));
  74.         }
  75.  
  76.         while ('\\' == LAST_CHAR(path)) /* Strip trailing backslash  */
  77.         {
  78.                 dir_flag = TRUE;
  79.                 LAST_CHAR(path) = '\0';
  80.         }
  81.  
  82.         s = r;
  83.  
  84.         /* Look for "\." in path        */
  85.  
  86.         while (NULL != (p = strstr(s, "\\.")))
  87.         {
  88.                 if ('.' == p[2])
  89.                 {
  90.                         /* Execute this section if ".." found        */
  91.  
  92.                         q = p - 1;
  93.                         while (q > r)           /* Backup one level  */
  94.                         {
  95.                                 if (*q == '\\')
  96.                                         break;
  97.                                 --q;
  98.                         }
  99.                         if (q > r)
  100.                         {
  101.                                 strcpy(q, p + 3);
  102.                                 s = q;
  103.                         }
  104.                         else if ('.' != *q)
  105.                         {
  106.                                 strcpy(q + ((*q == '\\') ? 1 : 0),
  107.                                         p + 3 + ((*(p + 3)) ? 1 : 0));
  108.                                 s = q;
  109.                         }
  110.                         else    s = ++p;
  111.  
  112.                 }
  113.                 else
  114.                 {
  115.                         /* Execute this section if "." found        */
  116.  
  117.                         q = p + 2;
  118.                         for ( ;*q && (*q != '\\'); ++q)
  119.                                 ;
  120.                         strcpy (p, q);
  121.                 }
  122.         }
  123.  
  124.         if (root_flag)  /* Embedded ".." could have bubbled up to
  125.                            root  */
  126.         {
  127.                 for (p = r; *p && ('.' == *p || '\\' == *p); ++p)
  128.                         ;
  129.                 if (r != p)
  130.                         strcpy(r, p);
  131.         }
  132.  
  133.         if (dir_flag)
  134.                 strcat(path, "\\");
  135.         return path;
  136. }
  137.