History log of /openbsd-current/usr.bin/tmux/cmd-show-environment.c
Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
# 1.28 21-Aug-2021 nicm

Add args parsing callback for some future work, currently unused.


# 1.27 20-Aug-2021 nicm

Hide struct args behind a couple of accessor functions.


Revision tags: OPENBSD_6_7_BASE OPENBSD_6_8_BASE OPENBSD_6_9_BASE
# 1.26 13-Apr-2020 nicm

Also move cmdq_item and cmdq_list into cmd-queue.c (this is to make its
use more clearly defined and preparation for some future work).


# 1.25 13-Apr-2020 nicm

Make struct cmd local to cmd.c and move it out of tmux.h.


# 1.24 31-Mar-2020 nicm

Add a way to mark environment variables as "hidden" so they can be used
by tmux but are not passed into the environment of new panes.


Revision tags: OPENBSD_6_2_BASE OPENBSD_6_3_BASE OPENBSD_6_4_BASE OPENBSD_6_5_BASE OPENBSD_6_6_BASE
# 1.23 22-Apr-2017 nicm

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.


Revision tags: OPENBSD_6_1_BASE
# 1.22 16-Oct-2016 nicm

Mass rename struct cmd_q to struct cmdq_item and related.


# 1.21 14-Oct-2016 nicm

Add CMD_AFTERHOOK flag to the easy commands that don't need any special handling.


# 1.20 10-Oct-2016 nicm

Add static in cmd-* and fix a few other nits.


Revision tags: OPENBSD_6_0_BASE
# 1.19 03-Mar-2016 nicm

show-* and set-* need to handle a missing target.


Revision tags: OPENBSD_5_9_BASE
# 1.18 19-Jan-2016 nicm

I no longer use my SourceForge address so replace it.


# 1.17 16-Dec-2015 nicm

showenv and setenv need to be CANFAIL.


# 1.16 14-Dec-2015 nicm

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.


# 1.15 13-Dec-2015 nicm

Use member names in cmd_entry definitions so I stop getting confused
about the order.


# 1.14 13-Dec-2015 nicm

show-options and environment need CANFAIL flag.


# 1.13 13-Dec-2015 nicm

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.


# 1.12 28-Oct-2015 nicm

Like options, move the environ struct into environ.c.


# 1.11 30-Aug-2015 nicm

Some style nits and dead assignments.


Revision tags: OPENBSD_5_8_BASE
# 1.10 13-Jul-2015 nicm

Add a -s flag to show-environment to output Bourne shell commands a la
ssh-agent. Mostly from Cam Hutchison with some changes by me.


Revision tags: OPENBSD_5_7_BASE
# 1.9 20-Oct-2014 nicm

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.


Revision tags: OPENBSD_5_5_BASE OPENBSD_5_6_BASE
# 1.8 10-Oct-2013 nicm

Remove the barely-used and unnecessary command check() function.


Revision tags: OPENBSD_5_4_BASE
# 1.7 24-Mar-2013 nicm

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.


Revision tags: OPENBSD_5_2_BASE OPENBSD_5_3_BASE
# 1.6 11-Jul-2012 nicm

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.


# 1.5 22-Mar-2012 nicm

Accept an argument to show-environment to show one variable, based on a
diff from Kazuhiko Sakaguchi.


Revision tags: OPENBSD_5_0_BASE OPENBSD_5_1_BASE
# 1.4 05-Apr-2011 nicm

Add a flag to cmd_find_session so that attach-session can prefer
unattached sessions when choosing the most recently used (if -t is not
given). Suggested by claudio@.


Revision tags: OPENBSD_4_9_BASE
# 1.3 04-Jan-2011 nicm

Clean up and simplify tmux command argument parsing.

Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.

This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).

This is overall more simple and consistent.

There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.


Revision tags: OPENBSD_4_7_BASE OPENBSD_4_8_BASE
# 1.2 13-Nov-2009 nicm

Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the
command entry structs and a couple of functions to check/set the flags.


# 1.1 08-Aug-2009 nicm

Infrastructure and commands to manage the environment for processes started
within tmux.

There is a global environment, copied from the external environment when the
server is started and each sesssion has an (initially empty) session
environment which overrides it.

New commands set-environment and show-environment manipulate or display the
environments.

A new session option, update-environment, is a space-separated list of
variables which are updated from the external environment into the session
environment every time a new session is created - the default is DISPLAY.


# 1.26 13-Apr-2020 nicm

Also move cmdq_item and cmdq_list into cmd-queue.c (this is to make its
use more clearly defined and preparation for some future work).


# 1.25 13-Apr-2020 nicm

Make struct cmd local to cmd.c and move it out of tmux.h.


# 1.24 31-Mar-2020 nicm

Add a way to mark environment variables as "hidden" so they can be used
by tmux but are not passed into the environment of new panes.


Revision tags: OPENBSD_6_2_BASE OPENBSD_6_3_BASE OPENBSD_6_4_BASE OPENBSD_6_5_BASE OPENBSD_6_6_BASE
# 1.23 22-Apr-2017 nicm

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.


Revision tags: OPENBSD_6_1_BASE
# 1.22 16-Oct-2016 nicm

Mass rename struct cmd_q to struct cmdq_item and related.


# 1.21 14-Oct-2016 nicm

Add CMD_AFTERHOOK flag to the easy commands that don't need any special handling.


# 1.20 10-Oct-2016 nicm

Add static in cmd-* and fix a few other nits.


Revision tags: OPENBSD_6_0_BASE
# 1.19 03-Mar-2016 nicm

show-* and set-* need to handle a missing target.


Revision tags: OPENBSD_5_9_BASE
# 1.18 19-Jan-2016 nicm

I no longer use my SourceForge address so replace it.


# 1.17 16-Dec-2015 nicm

showenv and setenv need to be CANFAIL.


# 1.16 14-Dec-2015 nicm

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.


# 1.15 13-Dec-2015 nicm

Use member names in cmd_entry definitions so I stop getting confused
about the order.


# 1.14 13-Dec-2015 nicm

show-options and environment need CANFAIL flag.


# 1.13 13-Dec-2015 nicm

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.


# 1.12 28-Oct-2015 nicm

Like options, move the environ struct into environ.c.


# 1.11 30-Aug-2015 nicm

Some style nits and dead assignments.


Revision tags: OPENBSD_5_8_BASE
# 1.10 13-Jul-2015 nicm

Add a -s flag to show-environment to output Bourne shell commands a la
ssh-agent. Mostly from Cam Hutchison with some changes by me.


Revision tags: OPENBSD_5_7_BASE
# 1.9 20-Oct-2014 nicm

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.


Revision tags: OPENBSD_5_5_BASE OPENBSD_5_6_BASE
# 1.8 10-Oct-2013 nicm

Remove the barely-used and unnecessary command check() function.


Revision tags: OPENBSD_5_4_BASE
# 1.7 24-Mar-2013 nicm

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.


Revision tags: OPENBSD_5_2_BASE OPENBSD_5_3_BASE
# 1.6 11-Jul-2012 nicm

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.


# 1.5 22-Mar-2012 nicm

Accept an argument to show-environment to show one variable, based on a
diff from Kazuhiko Sakaguchi.


Revision tags: OPENBSD_5_0_BASE OPENBSD_5_1_BASE
# 1.4 05-Apr-2011 nicm

Add a flag to cmd_find_session so that attach-session can prefer
unattached sessions when choosing the most recently used (if -t is not
given). Suggested by claudio@.


Revision tags: OPENBSD_4_9_BASE
# 1.3 04-Jan-2011 nicm

Clean up and simplify tmux command argument parsing.

Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.

This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).

This is overall more simple and consistent.

There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.


Revision tags: OPENBSD_4_7_BASE OPENBSD_4_8_BASE
# 1.2 13-Nov-2009 nicm

Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the
command entry structs and a couple of functions to check/set the flags.


# 1.1 08-Aug-2009 nicm

Infrastructure and commands to manage the environment for processes started
within tmux.

There is a global environment, copied from the external environment when the
server is started and each sesssion has an (initially empty) session
environment which overrides it.

New commands set-environment and show-environment manipulate or display the
environments.

A new session option, update-environment, is a space-separated list of
variables which are updated from the external environment into the session
environment every time a new session is created - the default is DISPLAY.


# 1.24 31-Mar-2020 nicm

Add a way to mark environment variables as "hidden" so they can be used
by tmux but are not passed into the environment of new panes.


Revision tags: OPENBSD_6_2_BASE OPENBSD_6_3_BASE OPENBSD_6_4_BASE OPENBSD_6_5_BASE OPENBSD_6_6_BASE
# 1.23 22-Apr-2017 nicm

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.


Revision tags: OPENBSD_6_1_BASE
# 1.22 16-Oct-2016 nicm

Mass rename struct cmd_q to struct cmdq_item and related.


# 1.21 14-Oct-2016 nicm

Add CMD_AFTERHOOK flag to the easy commands that don't need any special handling.


# 1.20 10-Oct-2016 nicm

Add static in cmd-* and fix a few other nits.


Revision tags: OPENBSD_6_0_BASE
# 1.19 03-Mar-2016 nicm

show-* and set-* need to handle a missing target.


Revision tags: OPENBSD_5_9_BASE
# 1.18 19-Jan-2016 nicm

I no longer use my SourceForge address so replace it.


# 1.17 16-Dec-2015 nicm

showenv and setenv need to be CANFAIL.


# 1.16 14-Dec-2015 nicm

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.


# 1.15 13-Dec-2015 nicm

Use member names in cmd_entry definitions so I stop getting confused
about the order.


# 1.14 13-Dec-2015 nicm

show-options and environment need CANFAIL flag.


# 1.13 13-Dec-2015 nicm

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.


# 1.12 28-Oct-2015 nicm

Like options, move the environ struct into environ.c.


# 1.11 30-Aug-2015 nicm

Some style nits and dead assignments.


Revision tags: OPENBSD_5_8_BASE
# 1.10 13-Jul-2015 nicm

Add a -s flag to show-environment to output Bourne shell commands a la
ssh-agent. Mostly from Cam Hutchison with some changes by me.


Revision tags: OPENBSD_5_7_BASE
# 1.9 20-Oct-2014 nicm

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.


Revision tags: OPENBSD_5_5_BASE OPENBSD_5_6_BASE
# 1.8 10-Oct-2013 nicm

Remove the barely-used and unnecessary command check() function.


Revision tags: OPENBSD_5_4_BASE
# 1.7 24-Mar-2013 nicm

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.


Revision tags: OPENBSD_5_2_BASE OPENBSD_5_3_BASE
# 1.6 11-Jul-2012 nicm

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.


# 1.5 22-Mar-2012 nicm

Accept an argument to show-environment to show one variable, based on a
diff from Kazuhiko Sakaguchi.


Revision tags: OPENBSD_5_0_BASE OPENBSD_5_1_BASE
# 1.4 05-Apr-2011 nicm

Add a flag to cmd_find_session so that attach-session can prefer
unattached sessions when choosing the most recently used (if -t is not
given). Suggested by claudio@.


Revision tags: OPENBSD_4_9_BASE
# 1.3 04-Jan-2011 nicm

Clean up and simplify tmux command argument parsing.

Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.

This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).

This is overall more simple and consistent.

There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.


Revision tags: OPENBSD_4_7_BASE OPENBSD_4_8_BASE
# 1.2 13-Nov-2009 nicm

Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the
command entry structs and a couple of functions to check/set the flags.


# 1.1 08-Aug-2009 nicm

Infrastructure and commands to manage the environment for processes started
within tmux.

There is a global environment, copied from the external environment when the
server is started and each sesssion has an (initially empty) session
environment which overrides it.

New commands set-environment and show-environment manipulate or display the
environments.

A new session option, update-environment, is a space-separated list of
variables which are updated from the external environment into the session
environment every time a new session is created - the default is DISPLAY.


Revision tags: OPENBSD_6_2_BASE
# 1.23 22-Apr-2017 nicm

Get rid of the extra layer of flags and cmd_prepare() and just store the
CMD_FIND_* flags in the cmd_entry and call it for the command. Commands
with special requirements call it themselves and update the target for
hooks to use.


Revision tags: OPENBSD_6_1_BASE
# 1.22 16-Oct-2016 nicm

Mass rename struct cmd_q to struct cmdq_item and related.


# 1.21 14-Oct-2016 nicm

Add CMD_AFTERHOOK flag to the easy commands that don't need any special handling.


# 1.20 10-Oct-2016 nicm

Add static in cmd-* and fix a few other nits.


Revision tags: OPENBSD_6_0_BASE
# 1.19 03-Mar-2016 nicm

show-* and set-* need to handle a missing target.


Revision tags: OPENBSD_5_9_BASE
# 1.18 19-Jan-2016 nicm

I no longer use my SourceForge address so replace it.


# 1.17 16-Dec-2015 nicm

showenv and setenv need to be CANFAIL.


# 1.16 14-Dec-2015 nicm

Instead of combined flags for -c, -s, -t, split into different sets
using an enum and simplify the parsing code.


# 1.15 13-Dec-2015 nicm

Use member names in cmd_entry definitions so I stop getting confused
about the order.


# 1.14 13-Dec-2015 nicm

show-options and environment need CANFAIL flag.


# 1.13 13-Dec-2015 nicm

Instead of every command resolving the target (-t or -s) itself, prepare
the state (client, session, winlink, pane) for it it before entering the
command. Each command provides some flags that tell the prepare step
what it is expecting.

This is a requirement for having hooks on commands (for example, if you
hook "select-window -t1:2", the hook command should to operate on window
1:2 not whatever it thinks is the current window), and should allow some
other target improvements.

The old cmd_find_* functions remain for the moment but that layer will
be dropped later.

Joint work with Thomas Adam.


# 1.12 28-Oct-2015 nicm

Like options, move the environ struct into environ.c.


# 1.11 30-Aug-2015 nicm

Some style nits and dead assignments.


Revision tags: OPENBSD_5_8_BASE
# 1.10 13-Jul-2015 nicm

Add a -s flag to show-environment to output Bourne shell commands a la
ssh-agent. Mostly from Cam Hutchison with some changes by me.


Revision tags: OPENBSD_5_7_BASE
# 1.9 20-Oct-2014 nicm

Instead of setting up the default keys by building the key struct
directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.


Revision tags: OPENBSD_5_5_BASE OPENBSD_5_6_BASE
# 1.8 10-Oct-2013 nicm

Remove the barely-used and unnecessary command check() function.


Revision tags: OPENBSD_5_4_BASE
# 1.7 24-Mar-2013 nicm

Add a command queue to standardize and simplify commands that call other
commands and allow a command to block execution of subsequent
commands. This allows run-shell and if-shell to be synchronous which has
been much requested.

Each client has a default command queue and commands are consumed one at
a time from it. A command may suspend execution from the queue by
returning CMD_RETURN_WAIT and then resume it by calling cmd_continue() -
for example run-shell does this from the callback that is fired after
the job is freed.

When the command queue becomes empty, command clients are automatically
exited (unless attaching). A callback is also fired - this is used for
nested commands in, for example, if-shell which can block execution of
the client's cmdq until a new cmdq becomes empty.

Also merge all the old error/info/print functions together and lose the
old curclient/cmdclient distinction - a cmdq is bound to one client (or
none if in the configuration file), this is a command client if
c->session is NULL otherwise an attached client.


Revision tags: OPENBSD_5_2_BASE OPENBSD_5_3_BASE
# 1.6 11-Jul-2012 nicm

Make command exec functions return an enum rather than -1/0/1 values and
add a new value to mean "leave client running but don't attach" to fix
problems with using some commands in a command sequence. Most of the
work by Thomas Adam, problem reported by "jspenguin" on SF bug 3535531.


# 1.5 22-Mar-2012 nicm

Accept an argument to show-environment to show one variable, based on a
diff from Kazuhiko Sakaguchi.


Revision tags: OPENBSD_5_0_BASE OPENBSD_5_1_BASE
# 1.4 05-Apr-2011 nicm

Add a flag to cmd_find_session so that attach-session can prefer
unattached sessions when choosing the most recently used (if -t is not
given). Suggested by claudio@.


Revision tags: OPENBSD_4_9_BASE
# 1.3 04-Jan-2011 nicm

Clean up and simplify tmux command argument parsing.

Originally, tmux commands were parsed in the client process into a
struct with the command data which was then serialised and sent to the
server to be executed. The parsing was later moved into the server (an
argv was sent from the client), but the parse step and intermediate
struct was kept.

This change removes that struct and the separate parse step. Argument
parsing and printing is now common to all commands (in arguments.c) with
each command left with just an optional check function (to validate the
arguments at parse time), the exec function and a function to set up any
key bindings (renamed from the old init function).

This is overall more simple and consistent.

There should be no changes to any commands behaviour or syntax although
as this touches every command please watch for any unexpected changes.


Revision tags: OPENBSD_4_7_BASE OPENBSD_4_8_BASE
# 1.2 13-Nov-2009 nicm

Get rid of the ugly CMD_CHFLAG macro and use a const string (eg "dDU") in the
command entry structs and a couple of functions to check/set the flags.


# 1.1 08-Aug-2009 nicm

Infrastructure and commands to manage the environment for processes started
within tmux.

There is a global environment, copied from the external environment when the
server is started and each sesssion has an (initially empty) session
environment which overrides it.

New commands set-environment and show-environment manipulate or display the
environments.

A new session option, update-environment, is a space-separated list of
variables which are updated from the external environment into the session
environment every time a new session is created - the default is DISPLAY.