Prepending a String to an Attribute

Example 39–10 prepends the string ADD to the description attribute of the entry to be added to the directory. For complete example code, refer to instance-path/examples/testpreop.c.

Before using the plug-in function as described here, set up the example suffix and register the plug-in. See Extending the Bind Operation and “To register the Plug-in”, as described previously.

To try the preoperation add function, add an entry for Quentin Cubbins who recently joined Example.com. Quentin’s LDIF entry, quentin.ldif, reads as shown in the following example.

Example 5–10 LDIF Entry

dn: uid=qcubbins,ou=People,dc=example,dc=com
objectclass: top
objectclass: person
objectclass: organizationalPerson
objectclass: inetOrgPerson
uid: qcubbins
givenName: Quentin
sn: Cubbins
cn: Quentin Cubbins
mail: qcubbins@example.com
userPassword: qcubbins
secretary: uid=bjensen,ou=People,dc=example,dc=com
description: Entry for Quentin Cubbins

The following example performs the prepend.

Example 5–11 Prepending ADD to the Description of the Entry (testpreop.c)

#include "slapi-plugin.h"

int
testpreop_add(Slapi_PBlock * pb)
{
    Slapi_Entry * entry;               /* Entry to add            */
    Slapi_Attr  * attribute;           /* Entry attributes        */
    Slapi_Value ** values;             /* Modified, duplicate vals*/
    int         connId, opId, rc = 0;
    long        msgId;

    /* Get the entry. */
    rc |= slapi_pblock_get(pb, SLAPI_ADD_ENTRY,       &entry);
    rc |= slapi_pblock_get(pb, SLAPI_OPERATION_MSGID, &msgId);
    rc |= slapi_pblock_get(pb, SLAPI_CONN_ID,         &connId);
    rc |= slapi_pblock_get(pb, SLAPI_OPERATION_ID,    &opId);

    /* Prepend ADD to values of description attribute.            */
    rc |= slapi_entry_attr_find(entry, "description", &attribute);
    if (rc == 0) {                 /* Found a description, so...  */
        int nvals, i, count = 0;
        const Slapi_Value * value;

        slapi_attr_get_numvalues(attribute, &nvals);
        values = (Slapi_Value **)
            slapi_ch_malloc((nvals+1)*sizeof(Slapi_Value *));

        for (                          /* ...loop for value...    */
            i = slapi_attr_first_value_const(attribute, &value);
            i != -1;
            i = slapi_attr_next_value_const(attribute, i, &value)
        ) {                            /* ...prepend "ADD ".      */
            const char  * string;
            char        * tmp;
            values[count] = slapi_value_dup(value);
            string = slapi_value_get_string(values[count]);
            tmp    = slapi_ch_malloc(5+strlen(string));
            strcpy(tmp, "ADD ");
            strcpy(tmp+4, string);
            slapi_value_set_string(values[count], tmp);
            slapi_ch_free((void **)&tmp);
            ++count;
        }

        values[count] = NULL;

    } else {                           /* entry has no desc.      */
        slapi_log_info_ex(
            SLAPI_LOG_INFO_AREA_PLUGIN,
            SLAPI_LOG_INFO_LEVEL_DEFAULT,
            msgId,
            connId,
            opId,
            "testpreop_add in test-preop plug-in",
            "Entry has no description attribute.\n"
        );
    }

    rc = slapi_entry_attr_replace_sv(entry, "description", values);
    if (rc != 0) {
        slapi_log_info_ex(
            SLAPI_LOG_INFO_AREA_PLUGIN,
            SLAPI_LOG_INFO_LEVEL_DEFAULT,
            msgId,
            connId,
            opId,
            "testpreop_add in test-preop plug-in",
            "Description attribute(s) not modified.\n"
        );
    }
    slapi_valuearray_free(&values);

    return 0;
}

Add Quentin’s entry to the directory. For example, if the entry is in quentin.ldif, type:

$ ldapmodify -h localhost -p 1389 -a -f quentin.ldif \
 -D uid=kvaughan,ou=people,dc=example,dc=com -w bribery
adding new entry uid=qcubbins,ou=People,dc=example,dc=com

$ 

At this point, search the directory for Quentin’s entry.

Example 5–12 Searching for the Entry

$ ldapsearch -h localhost -p 1389 -b dc=example,dc=com uid=qcubbins
version: 1
dn: uid=qcubbins,ou=People,dc=example,dc=com
objectClass: top
objectClass: person
objectClass: organizationalPerson
objectClass: inetOrgPerson
uid: qcubbins
givenName: Quentin
sn: Cubbins
cn: Quentin Cubbins
mail: qcubbins@example.com
secretary: uid=bjensen,ou=People,dc=example,dc=com
description: ADD Entry for Quentin Cubbins
$ 

Notice the value of the description attribute.

Delete Quentin’s entry so you can use it again later as an example.

$ ldapdelete -D uid=kvaughan,ou=people,dc=example,dc=com -w bribery \
 uid=qcubbins,ou=people,dc=example,dc=com

Turn off the preoperation plug-in to avoid prepending ADD to all the entries that you add.

$ dsconf disable-plugin -h localhost -p 1389 "Test Preop"
$ dsadm restart instance-path