PAM_ENV.CONF(5) Linux-PAM Manual PAM_ENV.CONF(5)
NAME
pam_env.conf, environment - the environment variables config files
DESCRIPTION
The /etc/security/pam_env.conf file specifies the environment variables
to be set, unset or modified by pam_env(8). When someone logs in, this
file is read and the environment variables are set according.
Each line starts with the variable name, there are then two possible
options for each variable DEFAULT and OVERRIDE. DEFAULT allows and
administrator to set the value of the variable to some default value,
if none is supplied then the empty string is assumed. The OVERRIDE
option tells pam_env that it should enter in its value (overriding the
default value) if there is one to use. OVERRIDE is not used, "" is
assumed and no override will be done.
VARIABLE [DEFAULT=[value]] [OVERRIDE=[value]]
(Possibly non-existent) environment variables may be used in values
using the ${string} syntax and (possibly non-existent) PAM_ITEMs may be
used in values using the @{string} syntax. Both the $ and @ characters
can be backslash escaped to be used as literal values values can be
delimited with "", escaped " not supported. Note that many environment
variables that you would like to use may not be set by the time the
module is called. For example, HOME is used below several times, but
many PAM applications don't make it available by the time you need it.
The "#" character at start of line (no space at front) can be used to
mark this line as a comment line.
The /etc/environment file specifies the environment variables to be
set. The file must consist of simple NAME=VALUE pairs on separate
lines. The pam_env(8) module will read the file after the pam_env.conf
file.
EXAMPLES
These are some example lines which might be specified in
/etc/security/pam_env.conf.
Set the REMOTEHOST variable for any hosts that are remote, default to
"localhost" rather than not being set at all
REMOTEHOST DEFAULT=localhost OVERRIDE=@{PAM_RHOST}
Set the DISPLAY variable if it seems reasonable
DISPLAY DEFAULT=${REMOTEHOST}:0.0 OVERRIDE=${DISPLAY}
Now some simple variables
PAGER DEFAULT=less
MANPAGER DEFAULT=less
LESS DEFAULT="M q e h15 z23 b80"
NNTPSERVER DEFAULT=localhost
PATH DEFAULT=${HOME}/bin:/usr/local/bin:/bin\
:/usr/bin:/usr/local/bin/X11:/usr/bin/X11
Silly examples of escaped variables, just to show how they work.
DOLLAR DEFAULT=\$
DOLLARDOLLAR DEFAULT= OVERRIDE=\$${DOLLAR}
DOLLARPLUS DEFAULT=\${REMOTEHOST}${REMOTEHOST}
ATSIGN DEFAULT="" OVERRIDE=\@
SEE ALSO
pam_env(8), pam.d(5), pam(8), environ(7)
AUTHOR
pam_env was written by Dave Kinchlea <kinch AT kinch.com>.
Linux-PAM Manual 04/01/2020 PAM_ENV.CONF(5)