1 .TH POSTNOTE 3
2 .SH NAME
3 postnote \- send a note to a process or process group
4 .SH SYNOPSIS
5 .B #include <u.h>
6 .br
7 .B #include <libc.h>
8 .PP
9 .nf
10 .B
11 int	postnote(int who, int pid, char *note)
12 .fi
13 .SH DESCRIPTION
14 .I Postnote
15 sends a note to a process or process group.
16 If
17 .I who
18 is
19 .BR PNPROC ,
20 then
21 .I note
22 is written to
23 .BI /proc/ pid /note\f1.
24 If
25 .I who
26 is
27 .BI PNGROUP , 
28 the note is delivered to the
29 process group by writing
30 .I note
31 to
32 .BI /proc/ pid /notepg\f1.
33 For
34 .B PNGROUP
35 only, if the calling process is in the target group, the note is
36 .I not
37 delivered to that process.
38 .PP
39 If the write is successful, zero is returned.
40 Otherwise \-1 is returned.
41 .SH SOURCE
42 .B /sys/src/libc/9sys/postnote.c
43 .SH "SEE ALSO"
44 .IR notify (3),
45 .IR intro (3),
46 .IR proc (3)
47 .SH DIAGNOSTICS
48 Sets
49 .IR errstr .