xref: /illumos-gate/usr/src/man/man3proc/Pwrite.3proc (revision e4f7ccbe1e17940fdbde623116bcc8cd761d9ffc)
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12.\" Copyright 2015 Joyent, Inc.
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14.Dd May 11, 2016
15.Dt PWRITE 3PROC
16.Os
17.Sh NAME
18.Nm Pwrite
19.Nd write data to the address space of a process
20.Sh LIBRARY
21.Lb libproc
22.Sh SYNOPSIS
23.In libproc.h
24.Ft ssize_t
25.Fo Pwrite
26.Fa "struct ps_prochandle *P"
27.Fa "const void *buf"
28.Fa "size_t nbyte"
29.Fa "uintptr_t address"
30.Fc
31.Sh DESCRIPTION
32The
33.Fn Pwrite
34function writes data from
35.Fa buf
36to the process handle
37.Fa P
38starting at the address
39.Fa address .
40It writes at most
41.Fa nbyte
42of data.
43The
44.Fn Pwrite
45function is logically analogous to the
46.Xr pwrite 2
47function.
48.Pp
49For live processes, this function is equivalent to writing to the
50/proc file system
51.Sy as
52file for the process.
53For core files, it writes to the logical address space of what was once the
54process and not the corresponding offset in the on-disk file.
55ELF objects grabbed through
56.Xr Pgrab_file 3PROC
57do not support being written to.
58.Pp
59The
60.Fn Pwrite
61function cannot be used to
62.Em extend
63the size of a mapping; writing to an unmapped region generates an
64error.
65.Sh RETURN VALUES
66Upon successful completion, the
67.Fn Pwrite
68function returns the number of bytes successfully written to
69.Fa P .
70This number is never greater than
71.Fa nbyte .
72Otherwise, it returns
73.Sy -1
74and
75.Sy errno
76is set to indicate an error.
77For the full list of errors see the
78.Sy DIAGNOSTICS
79section in
80.Xr proc 5
81and
82the
83.Sy ERRORS
84section in
85.Xr pwrite 2 .
86.Pp
87In addition, the
88.Fn Pwrite
89function will fail if:
90.Bl -tag -width Er
91.It Er EIO
92.Fa P
93refers to an ELF object and not a core file or active process.
94.El
95.Sh INTERFACE STABILITY
96.Sy Uncommitted
97.Sh MT-LEVEL
98See
99.Sy LOCKING
100in
101.Xr libproc 3LIB .
102.Sh SEE ALSO
103.Xr pwrite 2 ,
104.Xr libproc 3LIB ,
105.Xr proc 5
106