adjmsg(9F)						   Kernel Functions for Drivers 						adjmsg(9F)

NAME

       adjmsg - trim bytes from a message

SYNOPSIS

       #include <sys/stream.h>

       int adjmsg(mblk_t *mp, ssize_t len);

INTERFACE LEVEL

       Architecture independent level 1 (DDI/DKI).

PARAMETERS

       mp	Pointer to the message to be trimmed.

       len	The number of bytes to be removed.

DESCRIPTION

       The  adjmsg()  function	removes  bytes from a message. |len| (the absolute value of len) specifies the number of bytes to be removed.  The
       adjmsg() function only trims bytes across message blocks of the same type.

       The adjmsg() function finds the maximal leading sequence of message blocks of the same type as that of mp and starts removing bytes  either
       from  the  head	of that sequence or from the tail of that sequence. If len is greater than 0, adjmsg() removes bytes from the start of the
       first message block in that sequence. If len is less than 0, it removes bytes from the end of the last message block in that sequence.

       The adjmsg() function fails if |len| is greater than the number of bytes in the maximal leading sequence it finds.

       The adjmsg() function may remove any except the first zero-length message block created during  adjusting.  It may also	remove	any  zero-
       length message blocks that occur within the scope of |len|.

RETURN VALUES

       The adjmsg() function returns:

       1	Successful completion.

       0	An error occurred.

CONTEXT

       The adjmsg() function can be called from user or interrupt context.

SEE ALSO

       STREAMS Programming Guide

SunOS 5.10							    20 Nov 1996 							adjmsg(9F)