User Guide

Ampex 1308911-02 5-51
libdd2 API Functions dst_setparam
5.16 dst_setparam
NAME
dst_setparam() - change tape drive data block size and tape device driver debug level.
SYNOPSIS
#include <dd2.h>
int dst_setparam(int fd, dst_param_st *parms);
DESCRIPTION
dst_setparam() changes tape drive data block size and/or tape device driver debug level. To
view the current settings, use the dst_getparam() function.
dst_setparam() is available to all users.
PARAMETERS
fd The file descriptor returned by the open call.
*parms Pointer to a structure of type
dst_param_st.
USAGE
dst_setparam() uses the *parms structure for both input and output.
• On input, the valid bit mask indicates which members specify parameter changes.
• On successful return, the valid bit mask identifies the members for which changes
were made.
• If the valid bit mask is different on return, it indicates that dst_setparam() could not
make all of the changes requested. To check the current parameter settings, use the
dst_getparam() function.
Before calling dst_setparam(), initialize the appropriate *parms structure members with new
values for the parameters you want to change, and set the
valid bit mask accordingly.
typedef struct dst_param
{
u_int valid; /* Valid members */
int blksize; /* Current blocksize in bytes */
u_int dbglevel; /* Device driver debug message level */
u_int attributes; /* Bit mask of attributes */
} dst_param_st;