Foot’s policy is to not set environment variables that identifies
it (except the well-known and established `TERM` variable).
We encourage applications to use terminfo to determine capabilities,
or terminal queries, when available. Or, at least use terminal queries
to detect the terminal and its version.
Setting environment variables is a bad idea since they are inherited
by all applications started by the terminal (which is the whole
point). But, this includes other terminal emulators, making it very
possible a terminal emulator gets mis-detected just because it was
started from another terminal.
Since there are a couple of terminal emulators that _do_ set
TERM_PROGRAM and TERM_PROGRAM_VERSION, unset these environment
variables to avoid being misdetected.
Closes#1349
This improves handling of symlinks (in CWD) when launching a new
terminal instance, either through ctrl+shift+n, or using the
--working-directory command line option.
Closes#1179
When this option is used, the child process in the new terminal
instance will inherit its environment from the footclient process,
instead of the foot server’s.
Implemented by sending (yet another) dynamic string list as part of
the client -> server setup packet. When the new option is *not* used,
the setup packet is now 2 bytes larger than before.
On the server side, the slave process now uses execvpe() instead of
execvp(). There’s plumbing to propagate a new ‘envp’ argument from
term_init() all the way down to slave_exec(). If ‘envp’ is NULL, we
use ‘environ’ instead (thus matching the old behavior of execvp()).
Closes#1004
Not doing so before calling sigaction(3) is "undefined" according to
POSIX[1]:
> Applications shall call either sigemptyset() or sigfillset() at least
> once for each object of type sigset_t prior to any other use of that
> object. If such an object is not initialized in this way, but is
> nonetheless supplied as an argument to any of pthread_sigmask(),
> sigaction(), sigaddset(), sigdelset(), sigismember(), sigpending(),
> sigprocmask(), sigsuspend(), sigtimedwait(), sigwait(), or
> sigwaitinfo(), the results are undefined.
The use of designated initializers means that sa_mask members were
still being initialized, but sigset_t is an opaque type and implicit
initialization doesn't necessarily produce the same results as using
sigemptyset(3) (although it typically does on most implementations).
[1]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigaddset.html
This seems to be slightly better supported than TERMINFO_DIRS. It also
simplifies our code, since it’s no longer an issue of whether to
append or not - we just set TERMINFO, and ignore whatever it was set
to before.
Also closes#687
As of 2021-07-31, ncurses ships its own version of foot’s terminfo.
Since:
* It doesn’t have the non-standard Sync,Tc,setrgbf,setrgbb
capabilities.
* It doesn’t set hs,fsl,dsl (statusbar).
* We want to be able to update our termminfo without waiting for an
ncurses release.
* Foot should be installable and usable on Linux systems that doesn’t
have the latest ncurses.
we still want to ship our own version. We can however not install it
to the default terminfo location (e.g. /usr/share/terminfo), since it
will collide with the ncurses provided files.
Our options are to either rename our terminfo to something else, or to
keep the name, but install our terminfo files somewhere else.
The first option would be the easy one. However, I think it makes
sense to use the same name. For example, a user that SSH’s into a
remote system that does *not* have our own version installed,
but *does* have the ncurses one, will gracefully fall back to that
one, which is better than manually having to set
e.g. TERM=xterm-256color.
Now, if we want to use the same name, we need to install it somewhere
else. But where? And how do we ensure our version is preferred over
the ncurses one?
I opted to $datadir/foot/terminfo (e.g. /usr/share/foot/terminfo) by
default. It makes it namespaced to foot (i.e. we’re not introducing a
new “standard” terminfo location), thus guaranteeing it wont collide
with ncurses.
To enable applications to find it, we export TERMINFO_DIRS. This is a
list of *additional* directories to search for terminfo files. If it’s
already defined, we *append* to it.
The nice thing with this is, if there’s no terminfo in that
location (e.g. when you SSH into a remote), the default terminfo
location is *also* searched. But only *after* having searched through
TERMINFO_DIRS.
In short: our version is preferred, but the ncurses one (or an older
version of our terminfo package!) will be used if ours cannot be
found.
To enable packagers full control over the new behavior, the existing
meson command line options have been modified, and a new option added:
-Dterminfo=disabled|enabled|auto: *build* and *install* the terminfo
files.
-Dcustom-terminfo-install-location=<path>: *where* the terminfo files
are expected to be found.
This *needs* to be set *even* if -Dterminfo=disabled. For example, if
the packaging script builds and packages the terminfo files separate
from the regular foot build. The path is *relative to $prefix*, and
defaults to $datadir/foot/terminfo.
This is the value that will be appended to TERMINFO_DIRS. Note that
you can set it to ‘no’, in which case foot will *not* set/modify
TERMINFO_DIRS. Only do this if you don’t intend to package foot’s
terminfo files at all (i.e. you plan on using the ncurses ones only).
-Ddefault-terminfo=foot. Allows overriding the default TERM
value. This should only be changed if the target platform doesn’t
support terminfo files.
Closes#671
\e[21m was previously used to disable bold. That changed a while ago,
to align foot with the majority of other terminal emulators.
\e[22m now disables both bold and dim.
When this change was done, the user notifications were not updated,
meaning the ‘message’ part was always in bold. This was never the
intended behavior.
slave: no need to restore signal handlers; they are automatically
restored as long as they are not SIG_IGN (which they never are in
foot).
spawn(): restore signal mask after fork. This fixes an issue where a
terminal spawned with ctrl+shift+n did not terminate when its shell
exited.
Closes#366
This is also done by libvte, alacritty, kitty and several other
terminal emulators as a way to indicate support for 24-bit RGB
colors. It generally also implies support for the xterm 256-color
palette and basic ECMA-48 colors.
This reverts commit 027a8de6f5.
I was a bit quick on this one, and only tested error cases. Turns out,
this causes foot to hang in a blocking read(3) on the event FD.
This is because while the FD has FD_CLOEXEC, that flag is per file
descriptor. I.e. the forked copy of the event fd is closed when we
exec(), but since this isn't a pipe, nothing is signaled to the parent
process, which thus remains blocking in read(3) since its copy of the
event fd hasn't been closed.
We _could_ write a dummy value on the event fd just before exec(), but
then we wouldn't be able to catch errors from exec() self - only
errors *before* exec().
Replace the pipe we used to communicate errors after fork(), but
before exec() to the parent process with an event FD.
The overhead in the kernel is much lower to setup an event fd,
compared to a pipe.
Since we need to restore the status flags anyway, there's nothing to
gain from emitting the user notifications after dup:ing the pts file
descriptor.
On the other hand, emitting user notifications *before* dup:ing means
we can still print error messages for e.g. write(3) errors.
We (need to) set O_NONBLOCK on the pts file description before
emitting the user-notifications, to ensure we don't block in write(3).
However, since file status flags are per *file*, not per
file *descriptor*, this ends up setting O_NONBLOCK on the dup:ed
stdin/stdout/stderr file descriptors too.
Not all clients want this, or can handle this.
Thus we need to restore the original flags before exec:ing the client.
This fixes "makepkg" build failures.
The main process is blocking and waiting for us to close the error
pipe (in exec(3), via O_CLOEXEC).
Thus, pts data will *not* be processed until we've exec:d the shell.
Because of this we must not write too much and block in write(3). Do
this by setting O_NONBLOCK on the pts fd (*after* dup:ing it to
stdin/stderr/sdout) and watch for EAGAIN EWOULDBLOCK.
* Rename user_warning to user_notification
* Add warning and error types (in addition to the existing deprecated)
* Simplify logic when emitting a user notification after forking; we
don't need to copy the notification data since we're in a new
process and have total control over that memory.
This is used when spawning the slave, to set its current working
directory just before we exec() the client.
In a regular foot instance, we set the cwd from getcwd().
In a foot server instance, each connecting client sends its cwd to the
server, and we use that.
