xref: /titanic_41/usr/src/man/man9f/dupmsg.9f (revision 721df37ded2cce623b0249cc35a872c3ce291b9b)
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Copyright 1989 AT&T
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DUPMSG 9F "Apr 11, 1991"
NAME
dupmsg - duplicate a message
SYNOPSIS

#include <sys/stream.h>



mblk_t *dupmsg(mblk_t *mp);
INTERFACE LEVEL

Architecture independent level 1 (DDI/DKI).

PARAMETERS
mp

Pointer to the message.

DESCRIPTION

dupmsg() forms a new message by copying the message block descriptors pointed to by mp and linking them. dupb(9F) is called for each message block. The data blocks themselves are not duplicated.

RETURN VALUES

If successful, dupmsg() returns a pointer to the new message block. Otherwise, it returns a NULL pointer. A return value of NULL indicates either memory depletion or the data block reference count, db_ref (see datab(9S)), has reached a limit (255). See dupb(9F).

CONTEXT

dupmsg() can be called from user, kernel, or interrupt context.

EXAMPLES

Example 1 Using dupmsg()

See copyb(9F) for an example using dupmsg().

SEE ALSO

copyb(9F), copymsg(9F), dupb(9F), datab(9S)

Writing Device Drivers

STREAMS Programming Guide