source/lib/ldb/examples/ldbreader.c

   1 /*
   2    example code for the ldb database library
   3
   4    Copyright (C) Brad Hards (bradh@frogmouth.net) 2005-2006
   5
   6      ** NOTE! The following LGPL license applies to the ldb
   7      ** library. This does NOT imply that all of Samba is released
   8      ** under the LGPL
   9
  10    This library is free software; you can redistribute it and/or
  11    modify it under the terms of the GNU Lesser General Public
  12    License as published by the Free Software Foundation; either
  13    version 3 of the License, or (at your option) any later version.
  14
  15    This library is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18    Lesser General Public License for more details.
  19
  20    You should have received a copy of the GNU Lesser General Public
  21    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 /** \example ldbreader.c
  25
  26 The code below shows a simple LDB application.
  27
  28 It lists / dumps the records in a LDB database to standard output.
  29
  30 */
  31
  32 #include "includes.h"
  33 #include "ldb/include/ldb.h"
  34 #include "ldb/include/ldb_errors.h"
  35
  36 /*
  37   ldb_ldif_write takes a function pointer to a custom output
  38   function. This version is about as simple as the output function can
  39   be. In a more complex example, you'd likely be doing something with
  40   the private data function (e.g. holding a file handle).
  41 */
  42 static int vprintf_fn(void *private_data, const char *fmt, ...)
  43 {
  44         int retval;
  45         va_list ap;
  46
  47         va_start(ap, fmt);
  48         /* We just write to standard output */
  49         retval = vprintf(fmt, ap);
  50         va_end(ap);
  51         /* Note that the function should return the number of
  52            bytes written, or a negative error code */
  53         return retval;
  54 }
  55
  56 int main(int argc, const char **argv)
  57 {
  58         struct ldb_context *ldb;
  59         const char *expression = "(dn=*)";
  60         struct ldb_result *resultMsg;
  61         int i;
  62
  63         /*
  64           This is the always the first thing you want to do in an LDB
  65           application - initialise up the context structure.
  66
  67           Note that you can use the context structure as a parent
  68           for talloc allocations as well
  69         */
  70         ldb = ldb_init(NULL);
  71
  72         /*
  73           We now open the database. In this example we just hard code the connection path.
  74
  75           Also note that the database is being opened read-only. This means that the
  76           call will fail unless the database already exists.
  77         */
  78         if (LDB_SUCCESS != ldb_connect(ldb, "tdb://tdbtest.ldb", LDB_FLG_RDONLY, NULL) ){
  79                 printf("Problem on connection\n");
  80                 exit(-1);
  81         }
  82
  83         /*
  84           At this stage we have an open database, and can start using it. It is opened
  85           read-only, so a query is possible.
  86
  87           We construct a search that just returns all the (sensible) contents. You can do
  88           quite fine grained results with the LDAP search syntax, however it is a bit
  89           confusing to start with. See RFC2254.
  90         */
  91         if (LDB_SUCCESS != ldb_search(ldb, NULL, LDB_SCOPE_DEFAULT,
  92                                       expression, NULL, &resultMsg) ) {
  93                 printf("Problem in search\n");
  94                 exit(-1);
  95         }
  96
  97         printf("%i records returned\n", resultMsg->count);
  98
  99         /*
 100           We can now iterate through the results, writing them out
 101           (to standard output) with our custom output routine as defined
 102           at the top of this file
 103         */
 104         for (i = 0; i < resultMsg->count; ++i) {
 105                 struct ldb_ldif ldifMsg;
 106
 107                 printf("Message: %i\n", i+1);
 108
 109                 ldifMsg.changetype = LDB_CHANGETYPE_NONE;
 110                 ldifMsg.msg = resultMsg->msgs[i];
 111                 ldb_ldif_write(ldb, vprintf_fn, NULL, &ldifMsg);
 112         }
 113
 114         /*
 115           There are two objects to clean up - the result from the
 116           ldb_search() query, and the original ldb context.
 117         */
 118         talloc_free(resultMsg);
 119
 120         talloc_free(ldb);
 121
 122         return 0;
 123 }