Hidden structures

Client-Library uses hidden structures to manage a variety of internal tasks.

A Client-Library application cannot directly access hidden structure internals. Instead, the application must call Client-Library routines to allocate, manipulate, and deallocate hidden structures.

Hidden structures include:

CS_BLKDESC, a control structure used by Client-Library’s and Server-Library’s bulk copy routines.
CS_CAP_TYPE, which is used to store capability information.
CS_COMMAND, which is used to send commands and process results.
CS_CONNECTION, which defines an individual client/server connection.
CS_CONTEXT, which defines a Client-Library programming context.
CS_LOCALE, which is used to store localization information.
CS_LOGINFO, the server login information structure. This structure, which is associated with a CS_CONNECTION, contains server login information such as user name and password.

The following table lists the routines and macros that allocate, manipulate, and deallocate hidden structures:.

**Table 2-9: Routines that manipulate hidden structures**
Structure	Routines	For more information
CS_BLKDESC	blk_alloc, blk_drop	Open Client and Open Server Common Libraries Reference Manual.
CS_CAP_TYPE	CS_CLR_CAPMASK, CS_SET_CAPMASK, CS_TST_CAPMASK	“Setting and retrieving multiple capabilities”.
CS_COMMAND	ct_cmd_alloc, ct_cmd_props, ct_cmd_drop	Reference pages for these routines.
CS_CONNECTION	ct_con_alloc, ct_con_props, ct_con_drop	Reference pages for these routines.
CS_CONTEXT	cs_ctx_alloc, ct_config, cs_config, cs_ctx_drop	Reference pages for these routines. CS-Library routines are documented in the Open Client and Open Server Common Libraries Reference Manual.
CS_LOCALE	cs_loc_alloc, cs_locale, cs_loc_drop	“International Support”. Open Client and Open Server Common Libraries Reference Manual.
CS_LOGINFO	ct_getloginfo, ct_setloginfo	Reference pages for these routines.