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✏️ Editing: README.pam_env

pam_env -- PAM module to set/unset environment variables

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DESCRIPTION

The pam_env PAM module allows the (un)setting of environment variables.
   Supported is the use of previously set environment variables as well as
   PAM_ITEMs such as PAM_RHOST.

By default rules for (un)setting of variables are taken from the config
   file /etc/security/pam_env.conf. An alternate file can be specified with
   the conffile option.

Second a file (/etc/environment by default) with simple KEY=VAL pairs on
   separate lines will be read. With the envfile option an alternate file can
   be specified. And with the readenv option this can be completly disabled.

Third it will read a user configuration file ($HOME/.pam_environment by
   default). The default file file can be changed with the user_envfile
   option and it can be turned on and off with the user_readenv option.

Since setting of PAM environment variables can have side effects to other
   modules, this module should be the last one on the stack.

OPTIONS

conffile=/path/to/pam_env.conf

Indicate an alternative pam_env.conf style configuration file to
           override the default. This can be useful when different services
           need different environments.

debug

A lot of debug information is printed with syslog(3).

envfile=/path/to/environment

Indicate an alternative environment file to override the default.
           The syntax are simple KEY=VAL pairs on separate lines. The export
           instruction can be specified for bash compatibility, but will be
           ignored. This can be useful when different services need different
           environments.

readenv=0|1

Turns on or off the reading of the file specified by envfile (0 is
           off, 1 is on). By default this option is on.

user_envfile=filename

Indicate an alternative .pam_environment file to override the
           default.The syntax is the same as for /etc/environment. The
           filename is relative to the user home directory. This can be
           useful when different services need different environments.

user_readenv=0|1

Turns on or off the reading of the user specific environment file.
           0 is off, 1 is on. By default this option is off as user supplied
           environment variables in the PAM environment could affect behavior
           of subsequent modules in the stack without the consent of the
           system administrator.

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
       XDG_DATA_HOME  @{HOME}/share/

Silly examples of escaped variables, just to show how they work.

DOLLAR         DEFAULT=\$
       DOLLARDOLLAR   DEFAULT=        OVERRIDE=\$${DOLLAR}
       DOLLARPLUS     DEFAULT=\${REMOTEHOST}${REMOTEHOST}
       ATSIGN         DEFAULT=""      OVERRIDE=\@

MR SKB