The following functions are used to modify an existing LDAP entry. There are four variations. typedef struct ldapmod { int mod_op; char *mod_type; union { char **modv_strvals; struct berval **modv_bvals; } mod_vals; } LDAPMod; #define mod_values mod_vals.modv_strvals #define mod_bvalues mod_vals.modv_bvals int ldap_modify_ext( LDAP *ld, const char *dn, LDAPMod **mods, LDAPControl **serverctrls, LDAPControl **clientctrls, int *msgidp ); int ldap_modify_ext_s( LDAP *ld, const char *dn, LDAPMod **mods, LDAPControl **serverctrls, LDAPControl **clientctrls ); int ldap_modify( LDAP *ld, const char *dn, LDAPMod **mods ); int ldap_modify_s( LDAP *ld, const char *dn, LDAPMod **mods ); Parameters are as follows: ld The session handle. dn The name of the entry to modify. mods A NULL-terminated array of modifications to make to the entry. serverctrls List of LDAP server controls. clientctrls List of client controls. msgidp This result parameter will be set to the message id of the request if the ldap_modify_ext() call succeeds. The fields in the LDAPMod structure have the following meanings: mod_op The modification operation to perform. It should be one of LDAP_MOD_ADD(0x00), LDAP_MOD_DELETE (0x01), or LDAP_MOD_REPLACE(0x02). This field also indicates the type of values included in the mod_vals union. It is logically ORed with LDAP_MOD_BVALUES (0x80) to select the mod_bvalues form. Otherwise, the mod_values form is used. mod_type The type of the attribute to modify. mod_vals The values (if any) to add, delete, or replace. Only one of the mod_values or mod_bvalues variants should be used, selected by ORing the mod_op field with the constant LDAP_MOD_BVALUES. The mod_values field is a NULL-terminated array of zero-terminated strings and mod_bvalues is a NULL- terminated array of berval structures that can be used to pass binary values such as images. For LDAP_MOD_ADD modifications, the given values are added to the entry, creating the attribute if necessary. For LDAP_MOD_DELETE modifications, the given values are deleted from the entry, removing the attribute if no values remain. If the entire attribute is to be deleted, the mod_vals field should be set to NULL. For LDAP_MOD_REPLACE modifications, the attribute will have the listed values after the modification, having been created if necessary, or removed if the mod_vals field is NULL. All modifications are performed in the order in which they are listed. The ldap_modify_ext() function initiates an asynchronous modify operation and returns the constant LDAP_SUCCESS if the request was successfully sent, or another LDAP error code if not. See Errors for more information about possible errors and how to interpret them. If successful, ldap_modify_ext() places the message id of the request in *msgidp. A subsequent call to ldap_ result() can be used to obtain the result of the modify. Similar to ldap_modify_ext(), the ldap_modify() function initiates an asynchronous modify operation and returns the message id of the operation initiated. As for ldap_modify_ext(), a subsequent call to ldap_result() can be used to obtain the result of the modify. In case of error, ldap_modify() will return -1, setting the session error parameters in the LDAP structure appropriately. The synchronous ldap_modify_ext_s() and ldap_modify_s() functions both return the result of the operation, either the constant LDAP_SUCCESS if the operation was successful, or another LDAP error code if it was not. See Errors for more information about possible errors and how to interpret them. The ldap_modify_ext() and ldap_modify_ext_s() functions support LDAPv3 server controls and client controls.