Tidy up the terminal detection and feature code and add named sets of

terminal features, each of which are defined in one place and map to a
builtin set of terminfo(5) capabilities. Features can be specified based
on TERM with a new terminal-features option or with the -T flag when
running tmux. tmux will also detect a few common terminals from the DA
and DSR responses.

This is intended to make it easier to configure tmux's use of
terminfo(5) even in the presence of outdated ncurses(3) or terminfo(5)
databases or for features which do not yet have a terminfo(5) entry.
Instead of having to grok terminfo(5) capability names and what they
should be set to in the terminal-overrides option, the user can
hopefully just give tmux a feature name and let it do the right thing.

The terminal-overrides option remains both for backwards compatibility
and to allow tweaks of individual capabilities.

tmux already did much of this already, this makes it tidier and simpler
to configure.

1 files changed, 73 insertions, 19 deletions

diff --git a/tmux.1 b/tmux.1
index 325ccd98..ca4e30e0 100644
--- a/tmux.1
+++ b/tmux.1
@@ -28,6 +28,7 @@
 .Op Fl f Ar file
 .Op Fl L Ar socket-name
 .Op Fl S Ar socket-path
+.Op Fl T Ar features
 .Op Ar command Op Ar flags
 .Ek
 .Sh DESCRIPTION
@@ -98,6 +99,8 @@ The options are as follows:
 Force
 .Nm
 to assume the terminal supports 256 colours.
+This is equivalent to
+.Fl T Ar 256 .
 .It Fl C
 Start in control mode (see the
 .Sx CONTROL MODE
@@ -186,6 +189,14 @@ that is set does not contain
 .Qq UTF-8
 or
 .Qq UTF8 .
+This is equivalent to
+.Fl T Ar UTF-8 .
+.It Fl T Ar features
+Set terminal features for the client.
+This is a comma-separated list of features.
+See the
+.Ic terminal-features
+option.
 .It Fl v
 Request verbose logging.
 Log messages will be saved into
@@ -3166,6 +3177,63 @@ disallowedWindowOps: 20,21,SetXprop
 Or changing this property from the
 .Xr xterm 1
 interactive menu when required.
+.It Ic terminal-features[] Ar string
+Set terminal features for terminal types read from
+.Xr terminfo 5 .
+.Nm
+has a set of named terminal features.
+Each will apply appropriate changes to the
+.Xr terminfo 5
+entry in use.
+.Pp
+.Nm
+can detect features for a few common terminals; this option can be used to
+easily tell tmux about features supported by terminals it cannot detect.
+The
+.Ic terminal-overrides
+option allows individual
+.Xr terminfo 5
+capabilities to be set instead,
+.Ic terminal-features
+is intended for classes of functionality supported in a standard way but not
+reported by
+.Xr terminfo 5 .
+Care must be taken only to configure this with features the terminal actually
+support.
+.Pp
+This is an array option where each entry is a colon-separated string made up
+of a terminal type pattern (matched using
+.Xr fnmatch 3 )
+followed by a list of terminal features.
+The available features are:
+.Bl -tag -width Ds
+.It 256
+Supports 256 colours with the SGR escape sequences.
+.It clipboard
+Allows setting the system clipboard.
+.It ccolour
+Allows setting the cursor colour.
+.It cstyle
+Allows setting the cursor style.
+.It margins
+Supports DECSLRM margins.
+.It overline
+Supports the overline SGR attribute.
+.It rectfill
+Supports the DECFRA rectangle fill escape sequence.
+.It RGB
+Supports RGB colour with the SGR escape sequences.
+.It sync
+Supports synchronized updates.
+.It title
+Supports
+.Xr xterm 1
+title setting.
+.It usstyle
+Allows underscore style and colour to be set.
+.It UTF-8
+Is able to handle UTF-8 output.
+.El
 .It Ic terminal-overrides[] Ar string
 Allow terminal descriptions read using
 .Xr terminfo 5
@@ -4383,6 +4451,7 @@ The following variables are available, where appropriate:
 .It Li "client_readonly" Ta "" Ta "1 if client is readonly"
 .It Li "client_session" Ta "" Ta "Name of the client's session"
 .It Li "client_termname" Ta "" Ta "Terminal name of client"
+.It Li "client_termfeatures" Ta "" Ta "Terminal features of client"
 .It Li "client_tty" Ta "" Ta "Pseudo terminal of client"
 .It Li "client_utf8" Ta "" Ta "1 if client supports UTF-8"
 .It Li "client_width" Ta "" Ta "Width of client"
@@ -5465,7 +5534,10 @@ The server crashed or otherwise exited without telling the client the reason.
 .Sh TERMINFO EXTENSIONS
 .Nm
 understands some unofficial extensions to
-.Xr terminfo 5 :
+.Xr terminfo 5.
+It is not normally necessary to set these manually, instead the
+.Ic terminal-features
+option should be used.
 .Bl -tag -width Ds
 .It Em \&Cs , Cr
 Set the cursor colour.
@@ -5479,33 +5551,15 @@ $ printf '\e033]12;red\e033\e\e'
 .Ed
 .It Em \&Smol
 Enable the overline attribute.
-The capability is usually SGR 53 and can be added to
-.Ic terminal-overrides
-as:
-.Bd -literal -offset indent
-Smol=\eE[53m
-.Ed
 .It Em \&Smulx
 Set a styled underscore.
 The single parameter is one of: 0 for no underscore, 1 for normal
 underscore, 2 for double underscore, 3 for curly underscore, 4 for dotted
 underscore and 5 for dashed underscore.
-The capability can typically be added to
-.Ic terminal-overrides
-as:
-.Bd -literal -offset indent
-Smulx=\eE[4::%p1%dm
-.Ed
 .It Em \&Setulc
 Set the underscore colour.
 The argument is (red * 65536) + (green * 256) + blue where each is between 0
 and 255.
-The capability can typically be added to
-.Ic terminal-overrides
-as:
-.Bd -literal -offset indent
-Setulc=\eE[58::2::%p1%{65536}%/%d::%p1%{256}%/%{255}%&%d::%p1%{255}%&%d%;m
-.Ed
 .It Em \&Ss , Se
 Set or reset the cursor style.
 If set, a sequence such as this may be used