usr.bin/rcs/src/curdir.c

   1 /* Copyright (C) 1982, 1988, 1989 Walter Tichy
   2  * All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms are permitted
   5  * provided that the above copyright notice and this paragraph are
   6  * duplicated in all such forms and that any documentation,
   7  * advertising materials, and other materials related to such
   8  * distribution and use acknowledge that the software was developed
   9  * by Walter Tichy.
  10  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  11  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  12  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  13  *
  14  * Report all problems and direct all questions to:
  15  *   rcs-bugs@cs.purdue.edu
  16  *
  17
  18
  19
  20
  21
  22
  23
  24 */
  25
  26 /*******************************************************************
  27  *                     curdir: get current directory
  28  *******************************************************************
  29  * returns full pathname of working (current) directory.
  30  * This is an adaptation of pwd, and works for grafted directories.
  31  * Unlike pwd, returns to current directory after it is finished.
  32  * Uses stdio buffering for directory reads.
  33  */
  34
  35  static char rcsid[]=
  36  "$Header: /pub/NetBSD/misc/repositories/cvsroot/src/usr.bin/rcs/src/Attic/curdir.c,v 1.1 1993/03/21 09:58:06 cgd Exp $";
  37
  38 /*******************************************************************
  39  *      $Log:   curdir.c,v $
  40  * Revision 3.3  89/05/01  15:11:49  narten
  41  * changed copyright header to reflect current distribution rules
  42  *
  43  * Revision 3.2  87/10/18  10:21:49  narten
  44  * Updating version numbers. Changes relative to 1.1 are actually
  45  * relative to 3.2
  46  *
  47  * Revision 1.1  84/01/23  14:50:01  kcs
  48  * Initial revision
  49  *
  50  * Revision 3.2  82/12/24  15:41:51  wft
  51  * Changed curdir() such that it returns a pointer to the pathname of
  52  * the current working directory, just as Berkeley's getcwd().
  53  *
  54  * Revision 3.1  82/10/18  21:16:21  wft
  55  * curdir() now uses stdio buffering for directory reads,
  56  * returns to working directory after done, and closes the directories.
  57  * A testprogram was also added.
  58  *
  59  *******************************************************************/
  60
  61
  62 #include        "rcsbase.h"
  63 #include        <sys/param.h>
  64 #include        <sys/stat.h>
  65 #include        <sys/dir.h>
  66 #define dot     "."
  67 #define dotdot  ".."
  68
  69
  70 static char cwd[NCPPN];
  71
  72 char * curdir()
  73 /* Function: places the pathname of the current directory into cwd
  74  * and returns a pointer to it. Returns NULL on failure.
  75  */
  76 {
  77         FILE    *file;
  78         struct  stat    d, dd;
  79         struct  direct  dir;
  80
  81         int rdev, rino;
  82         int off;
  83         register i,j;
  84
  85         cwd[off= 0] = '/';
  86         cwd[1] = '\0';
  87         stat("/", &d);
  88         rdev = d.st_dev;
  89         rino = d.st_ino;
  90         for (;;) {
  91                 if (stat(dot, &d)<0) return NULL;
  92                 if (d.st_ino==rino && d.st_dev==rdev) {
  93                         if (cwd[off] == '/') cwd[off] = '\0';
  94                         chdir(cwd); /*change back to current directory*/
  95                         return cwd;
  96                 }
  97                 if ((file = fopen(dotdot,"r")) == NULL) return NULL;
  98                 if (fstat(fileno(file), &dd)<0) goto fail;
  99                 chdir(dotdot);
 100                 if(d.st_dev == dd.st_dev) {
 101                         if(d.st_ino == dd.st_ino) {
 102                             if (cwd[off] == '/') cwd[off] = '\0';
 103                             chdir(cwd); /*change back to current directory*/
 104                             fclose(file);
 105                             return cwd;
 106                         }
 107                         do {
 108                             if (fread((char *)&dir, sizeof(dir), 1, file) !=1)
 109                                 goto fail;
 110                         } while (dir.d_ino != d.st_ino);
 111                 }
 112                 else do {
 113                         if(fread((char *)&dir, sizeof(dir), 1, file) != 1) {
 114                             goto fail;
 115                         }
 116                         stat(dir.d_name, &dd);
 117                 } while(dd.st_ino != d.st_ino || dd.st_dev != d.st_dev);
 118                 fclose(file);
 119
 120                 /* concatenate file name */
 121                 i = -1;
 122                 while (dir.d_name[++i] != 0);
 123                 for(j=off+1; j>0; --j)
 124                         cwd[j+i+1] = cwd[j];
 125                 off=i+off+1;
 126                 cwd[i+1] = '/';
 127                 for(--i; i>=0; --i)
 128                         cwd[i+1] = dir.d_name[i];
 129         } /* end for */
 130
 131 fail:   fclose(file);
 132         return NULL;
 133 }
 134
 135
 136 #ifdef TEST
 137 main ()
 138 {
 139         printf ("pwd = %s\n", curdir());
 140 }
 141 #endif TEST
 142