/ mesg -- set current tty to accept or forbid messages .globl ttyn clr r0 jsr pc,ttyn movb r0,ttyno sys stat; ttyx; stbuf bes error cmp (sp)+,$1 beq flip tst (sp)+ mov (sp)+,r0 cmpb (r0),$'n beq setno br setyes flip: bit $2,stbuf+4 beq setyes setno: sys chmod; ttyx; 600 bes error br say setyes: sys chmod; ttyx; 622 bes error say: bit $2,stbuf+4 beq wasno wasyes: movb $'y,nmes+4 wasno: mov $1,r0 sys write; nmes; 6 sys exit nmes: <was n\n> error: mov $1,r0 sys write; 1f; 2 sys exit 1: <?\n> ttyx: </dev/tty0\0> ttyno = .-2 .even stbuf: .=.+40.