lib/rmobj.c

   1 /*
   2  * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/NoticeExplan/
  31  */
  32
  33 /* $Id: rmobj.c,v 1.5 2009/07/20 10:59:32 vapier Exp $ */
  34
  35 /**********************************************************
  36  *
  37  *    OS Testing - Silicon Graphics, Inc.
  38  *
  39  *    FUNCTION NAME     : rmobj()
  40  *
  41  *    FUNCTION TITLE    : Remove an object
  42  *
  43  *    SYNOPSIS:
  44  *      int rmobj(char *obj, char **errmsg)
  45  *
  46  *    AUTHOR            : Kent Rogers
  47  *
  48  *    INITIAL RELEASE   : UNICOS 7.0
  49  *
  50  *    USER DESCRIPTION
  51  *      This routine will remove the specified object.  If the specified
  52  *      object is a directory, it will recursively remove the directory
  53  *      and everything underneath it.  It assumes that it has privilege
  54  *      to remove everything that it tries to remove.  If rmobj() encounters
  55  *      any problems, and errmsg is not NULL, errmsg is set to point to a
  56  *      string explaining the error.
  57  *
  58  *    DETAILED DESCRIPTION
  59  *      Allocate space for the directory and its contents
  60  *      Open the directory to get access to what is in it
  61  *      Loop through the objects in the directory:
  62  *        If the object is not "." or "..":
  63  *          Determine the file type by calling lstat()
  64  *          If the object is not a directory:
  65  *            Remove the object with unlink()
  66  *         Else:
  67  *            Call rmobj(object) to remove the object's contents
  68  *            Determine the link count on object by calling lstat()
  69  *            If the link count >= 3:
  70  *              Remove the directory with unlink()
  71  *            Else
  72  *               Remove the directory with rmdir()
  73  *      Close the directory and free the pointers
  74  *
  75  *    RETURN VALUE
  76  *      If there are any problems, rmobj() will set errmsg (if it was not
  77  *      NULL) and return -1.  Otherwise it will return 0.
  78  *
  79  ************************************************************/
  80 #include <errno.h>         /* for errno */
  81 #include <stdio.h>         /* for NULL */
  82 #include <stdlib.h>        /* for malloc() */
  83 #include <string.h>        /* for string function */
  84 #include <limits.h>        /* for PATH_MAX */
  85 #include <sys/types.h>     /* for opendir(), readdir(), closedir(), stat() */
  86 #include <sys/stat.h>      /* for [l]stat() */
  87 #include <dirent.h>        /* for opendir(), readdir(), closedir() */
  88 #include <unistd.h>        /* for rmdir(), unlink() */
  89 #include "rmobj.h"
  90
  91 #define SYSERR strerror(errno)
  92
  93 int
  94 rmobj(char *obj, char **errmsg)
  95 {
  96    int           ret_val = 0;       /* return value from this routine */
  97    DIR           *dir;              /* pointer to a directory */
  98    struct dirent *dir_ent;          /* pointer to directory entries */
  99    char          dirobj[PATH_MAX];  /* object inside directory to modify */
 100    struct stat   statbuf;           /* used to hold stat information */
 101    static char   err_msg[1024];     /* error message */
 102
 103    /* Determine the file type */
 104    if ( lstat(obj, &statbuf) < 0 ) {
 105       if ( errmsg != NULL ) {
 106          sprintf(err_msg, "lstat(%s) failed; errno=%d: %s",
 107                  obj, errno, SYSERR);
 108          *errmsg = err_msg;
 109       }
 110       return -1;
 111    }
 112
 113    /* Take appropriate action, depending on the file type */
 114    if ( (statbuf.st_mode & S_IFMT) == S_IFDIR ) {
 115       /* object is a directory */
 116
 117       /* Do NOT perform the request if the directory is "/" */
 118       if ( !strcmp(obj, "/") ) {
 119          if ( errmsg != NULL ) {
 120             sprintf(err_msg, "Cannot remove /");
 121             *errmsg = err_msg;
 122          }
 123          return -1;
 124       }
 125
 126       /* Open the directory to get access to what is in it */
 127       if ( (dir = opendir(obj)) == NULL ) {
 128          if ( rmdir(obj) != 0 ) {
 129             if ( errmsg != NULL ) {
 130                sprintf(err_msg, "rmdir(%s) failed; errno=%d: %s",
 131                        obj, errno, SYSERR);
 132                *errmsg = err_msg;
 133             }
 134             return -1;
 135          } else {
 136             return 0;
 137          }
 138       }
 139
 140       /* Loop through the entries in the directory, removing each one */
 141       for ( dir_ent = (struct dirent *)readdir(dir);
 142             dir_ent != NULL;
 143             dir_ent = (struct dirent *)readdir(dir)) {
 144
 145          /* Don't remove "." or ".." */
 146          if ( !strcmp(dir_ent->d_name, ".") || !strcmp(dir_ent->d_name, "..") )
 147             continue;
 148
 149          /* Recursively call this routine to remove the current entry */
 150          sprintf(dirobj, "%s/%s", obj, dir_ent->d_name);
 151          if ( rmobj(dirobj, errmsg) != 0 )
 152             ret_val = -1;
 153       }
 154
 155       /* Close the directory */
 156       closedir(dir);
 157
 158       /* If there were problems removing an entry, don't attempt to
 159          remove the directory itself */
 160       if ( ret_val == -1 )
 161          return -1;
 162
 163       /* Get the link count, now that all the entries have been removed */
 164       if ( lstat(obj, &statbuf) < 0 ) {
 165          if ( errmsg != NULL ) {
 166             sprintf(err_msg, "lstat(%s) failed; errno=%d: %s",
 167                     obj, errno, SYSERR);
 168             *errmsg = err_msg;
 169          }
 170          return -1;
 171       }
 172
 173       /* Remove the directory itself */
 174       if ( statbuf.st_nlink >= 3 ) {
 175          /* The directory is linked; unlink() must be used */
 176          if ( unlink(obj) < 0 ) {
 177             if ( errmsg != NULL ) {
 178                sprintf(err_msg, "unlink(%s) failed; errno=%d: %s",
 179                        obj, errno, SYSERR);
 180                *errmsg = err_msg;
 181             }
 182             return -1;
 183          }
 184       } else {
 185          /* The directory is not linked; remove() can be used */
 186          if ( remove(obj) < 0 ) {
 187             if ( errmsg != NULL ) {
 188                sprintf(err_msg, "remove(%s) failed; errno=%d: %s",
 189                        obj, errno, SYSERR);
 190                *errmsg = err_msg;
 191             }
 192             return -1;
 193          }
 194       }
 195    } else {
 196       /* object is not a directory; just use unlink() */
 197       if ( unlink(obj) < 0 ) {
 198          if ( errmsg != NULL ) {
 199             sprintf(err_msg, "unlink(%s) failed; errno=%d: %s",
 200                     obj, errno, SYSERR);
 201             *errmsg = err_msg;
 202          }
 203          return -1;
 204       }
 205    }  /* if obj is a directory */
 206
 207    /*
 208     * Everything must have went ok.
 209     */
 210    return 0;
 211 }  /* rmobj() */