iofunc_stat_default()

Arguments:

ctp

A pointer to a resmgr_context_t structure that the resource-manager library uses to pass context information between functions.

msg

A pointer to the io_stat_t structure that contains the message that the resource manager received; see below.

ocb

A pointer to the iofunc_ocb_t structure for the Open Control Block that was created when the client opened the resource.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The iofunc_stat_default() function implements POSIX semantics for the client's stat() or fstat() call, which is received as an _IO_STAT message by the resource manager.

You can place this function directly into the resmgr_io_funcs_t table passed as the io_funcs argument to resmgr_attach(), at the stat position, or you can call iofunc_func_init() to initialize all of the functions to their default values.

The iofunc_stat_default() function calls:

• iofunc_time_update(), to ensure that the time entries in the ocb->attr structure are current and valid
• iofunc_stat_format() to construct a status entry based on the information in the ocb->attr structure.

The iofunc_stat_default() function returns (via the status argument to MsgReply()) the form of the stat structure.

io_stat_t structure

The io_stat_t structure holds the _IO_STAT message received by the resource manager:

struct _io_stat {
    uint16_t                    type;
    uint16_t                    combine_len;
    union {
       uint32_t                 zero;
       uint32_t                 format;
    };
};

typedef union {
    struct _io_stat             i;
    struct __stat_t32_2001      o_t32_2001;
    struct __stat_t32_2008      o_t32_2008;
    struct __stat_t64_2008      o_t64_2008;
    struct stat                 o;
} io_stat_t;

The I/O message structures are unions of an input message (coming to the resource manager) and an output or reply message (going back to the client).

The i member is a structure of type _io_stat that contains the following members:

type

_IO_STAT.

combine_len

If the message is a combine message, _IO_COMBINE_FLAG is set in this member. For more information, see Combine Messages chapter of Writing a Resource Manager.

format

The form of the information; one of the following:

• _STAT_FORM_UNSET — unknown; this is assumed to be the same as _STAT_FORM_T32_2001
• _STAT_FORM_T32_2001 — 32-bit fields, POSIX 2001
• _STAT_FORM_T32_2008 — 32-bit fields, POSIX 2008
• _STAT_FORM_T64_2008 — 64-bit fields, POSIX 2008
• _STAT_FORM_SYS_2008 — _STAT_FORM_T32_2008 in programs compiled for a 32-bit architecture, or _STAT_FORM_T64_2008 in programs compiled for a 64-bit architecture.
• _STAT_FORM_PREFERRED — the preferred form: _STAT_FORM_T32_2001 in programs compiled for a 32-bit architecture, or _STAT_FORM_T64_2008 in programs compiled for a 64-bit architecture.

Note:

The _STAT_FORM_UNSET, _STAT_FORM_T32_2001, and _STAT_FORM_T32_2008 values are legacy values for 32-bit targets and shouldn't be used in this release. Also, _STAT_FORM_SYS_2008 and _STAT_FORM_PREFERRED are always the same as _STAT_FORM_T64_2008 because only 64-bit targets are supported.

The o* members are variants of a struct stat, corresponding to the requested form.

Returns:

-1, to indicate to the resource manager library that it should return one part from the ctp->iov structure (see resmgr_context_t) to the client, or an errno value if an error occurred.

Classification:

QNX OS