SCO OpenServer

subyte(D3oddi)

subyte -- store a character in user data space

Synopsis

int subyte(caddr_t addr, unsigned char val);

Description

The subyte( ) function stores one character in the user's data space.

Arguments

addr: Address in the user's data space where the character is to be stored.
val: Value to be stored.

Return values

subyte returns -1 if the address addr is invalid; otherwise it returns 0 (zero).

Usage

If you are storing data in u.u_base, consider using passc(D3oddi) instead of subyte( ), because it updates u.u_count, u.u_offset, and u.u_base for you and provides error handling through u.u_error. Otherwise, the driver code must increase or decrease these members as appropriate:

   u.u_count -= cnt;
   u.u_offset += cnt;
   u.u_base += cnt;

If 0xff could be present in the data being stored in user space, use copyout(D3oddi) instead of subyte or passc, since a -1 in the data is interpreted as an error condition.

Context and synchronization

User context.

Hardware applicability

All

Version applicability

oddi: 1, 2, 2mp, 3, 3mp, 4, 4mp, 5, 5mp, 6, 6mp

SVR5 DDI compatibility

DDI does not support this function. Use the subyte( ) with calls to the copyout(D3) function instead.

References

copyout(D3oddi), fubyte(D3oddi), fuword(D3oddi), passc(D3oddi), suword(D3oddi)

``Data, copying'' in HDK Technical Reference