[thirdparty/man-pages.git] / man5 / proc_pid_environ.5

.\" Copyright (C) 1994, 1995, Daniel Quinlan <quinlan@yggdrasil.com>
.\" Copyright (C) 2002-2008, 2017, Michael Kerrisk <mtk.manpages@gmail.com>
.\" Copyright (C) 2023, Alejandro Colomar <alx@kernel.org>
.\"
.\" SPDX-License-Identifier: GPL-3.0-or-later
.\"
.TH proc_pid_environ 5 (date) "Linux man-pages (unreleased)"
.SH NAME
/proc/pid/environ \- initial environment
.SH DESCRIPTION
.TP
.IR /proc/ pid /environ
This file contains the initial environment that was set
when the currently executing program was started via
.BR execve (2).
The entries are separated by null bytes (\[aq]\e0\[aq]),
and there may be a null byte at the end.
Thus, to print out the environment of process 1, you would do:
.IP
.in +4n
.EX
.RB "$" " cat /proc/1/environ | tr \[aq]\e000\[aq] \[aq]\en\[aq]"
.EE
.in
.IP
If, after an
.BR execve (2),
the process modifies its environment
(e.g., by calling functions such as
.BR putenv (3)
or modifying the
.BR environ (7)
variable directly),
this file will
.I not
reflect those changes.
.IP
Furthermore, a process may change the memory location that this file refers via
.BR prctl (2)
operations such as
.BR PR_SET_MM_ENV_START .
.IP
Permission to access this file is governed by a ptrace access mode
.B PTRACE_MODE_READ_FSCREDS
check; see
.BR ptrace (2).
.SH SEE ALSO
.BR proc (5)
Commit	Line	Data
49ae7926 AC	1	.\" Copyright (C) 1994, 1995, Daniel Quinlan <quinlan@yggdrasil.com>
	2	.\" Copyright (C) 2002-2008, 2017, Michael Kerrisk <mtk.manpages@gmail.com>
	3	.\" Copyright (C) 2023, Alejandro Colomar <alx@kernel.org>
	4	.\"
	5	.\" SPDX-License-Identifier: GPL-3.0-or-later
	6	.\"
	7	.TH proc_pid_environ 5 (date) "Linux man-pages (unreleased)"
	8	.SH NAME
	9	/proc/pid/environ \- initial environment
	10	.SH DESCRIPTION
	11	.TP
	12	.IR /proc/ pid /environ
	13	This file contains the initial environment that was set
	14	when the currently executing program was started via
	15	.BR execve (2).
	16	The entries are separated by null bytes (\[aq]\e0\[aq]),
	17	and there may be a null byte at the end.
	18	Thus, to print out the environment of process 1, you would do:
	19	.IP
	20	.in +4n
	21	.EX
	22	.RB "$" " cat /proc/1/environ \| tr \[aq]\e000\[aq] \[aq]\en\[aq]"
	23	.EE
	24	.in
	25	.IP
	26	If, after an
	27	.BR execve (2),
	28	the process modifies its environment
	29	(e.g., by calling functions such as
	30	.BR putenv (3)
	31	or modifying the
	32	.BR environ (7)
	33	variable directly),
	34	this file will
	35	.I not
	36	reflect those changes.
	37	.IP
	38	Furthermore, a process may change the memory location that this file refers via
	39	.BR prctl (2)
	40	operations such as
	41	.BR PR_SET_MM_ENV_START .
	42	.IP
	43	Permission to access this file is governed by a ptrace access mode
	44	.B PTRACE_MODE_READ_FSCREDS
	45	check; see
	46	.BR ptrace (2).
	47	.SH SEE ALSO
	48	.BR proc (5)