Windows#

slosh runs natively on Windows 10/11, on both x86-64 and ARM64. It is one slosh.exe with no runtime dependency beyond the OS.

The build is a cross-compile, from a mac or a Linux box:

make -f Makefile.windows ARCH=x86_64
make -f Makefile.windows ARCH=aarch64

ARCH defaults to aarch64. The vendored terminal core is cross-compiled the same way and lands in vendor/libghostty-vt/zig-out-win-<arch>, so the two architectures never share an output directory.

The binary appears at build/win-<arch>/slosh.exe; copy that to the Windows machine.

For a release, make -f Makefile.windows ARCH=<arch> dist stages the same build as dist/slosh-<version>-windows-<arch>.zip (the binary plus the same licensing paperwork the linux tarballs carry), and make release builds both architectures alongside the linux and macOS artifacts, covered by the same SHA256SUMS.

What it does there#

Everything the POSIX build does: panes, splits, tabs, detachable sessions, the config file and its live reload, the control socket, the mouse. Panes run cmd.exe by default; %ComSpec% if you have pointed it elsewhere, and shell in the config file wins over both. slosh ls, slosh -s NAME cmd ... and slosh --script behave as documented.

Sessions live in %LOCALAPPDATA%\slosh rather than $XDG_RUNTIME_DIR: a session socket is machine-local by definition and must not follow a roaming profile onto another host.

How it works#

The port is a compatibility layer, not a fork: compat/win/ holds stub <poll.h>, <sys/socket.h>, <termios.h> and friends that redirect to include/compat_win.h, which is force-included ahead of every translation unit. The existing sources keep their POSIX includes and their POSIX call sites, and the platform differences are answered in one place.

Three decisions carry most of it.

Everything the event loop waits on is a socket. On POSIX a pty master, an inotify descriptor and a unix socket are all file descriptors, so one poll() covers them. Windows has no such union: a ConPTY hands back pipe HANDLEs and WSAPoll waits on SOCKETs and nothing else. Rather than rewrite the loop around WaitForMultipleObjects (which caps at 64 objects and cannot express POLLOUT), each non-socket source gets a pump thread that copies it into one end of a loopback socketpair. server.c's loop is then byte-for-byte the POSIX one, and only what sits behind the descriptor differs. The config watcher (ReadDirectoryChangesW) and the client's console input reach the loop the same way.

Socket descriptors are tagged, not guessed. A wrapped SOCKET is returned as SL_SOCK_BASE + slot, so read, write, close and poll can tell a socket from a CRT file descriptor with certainty rather than inferring it from the numeric range. That is why socket() and accept() are shimmed too: an untagged descriptor escaping into the loop is the one failure mode this scheme has, and it is worth closing completely.

A pane is a ConPTY. src/pty_win.c implements the same three functions as src/pty.c (spawn, resize, close) on CreatePseudoConsole, with the pty's fd being the pollable end of its pump pair and its pid a real Windows process id, so the existing kill and wait paths work unchanged.

Two details are worth knowing, because both are invisible until they bite.

A pseudoconsole does not stop the child inheriting your stdio. A child attached to one is supposed to take its stdio from that console, but CreateProcess copies the parent's standard handles into the child when STARTF_USESTDHANDLES is absent, and those win. With slosh's own stdout redirected (a pipe under ssh, a file under --script, a log under the daemon), the shell wrote its banner into slosh's output instead of into the pane. The symptom was a pane with a correct title and an empty body, because ConPTY emits the title itself. pty_win.c clears the three standard handles for the duration of the CreateProcess call, leaving the child nothing to inherit.

A ConPTY never reports EOF. On POSIX the pty master reports end-of-file once the last slave descriptor closes, which happens as the child dies, and pane_pump()'s read() returning 0 is the entire mechanism by which a pane learns its program is gone. A ConPTY gives no such signal: the output pipe belongs to the pseudoconsole, not to the child, so it stays open after the child exits and the read never ends. A pane whose shell had been told exit sat there looking alive forever. So the exit is waited for explicitly, on the process handle, and ClosePseudoConsole is what then produces the EOF: the console flushes what the child left behind and closes its end, and the output pump sees the end of the stream exactly as it would on a pty.

There are two quoting conventions, and cmd.exe uses the other one. Windows passes a command string, not a vector, so the quoting rules belong to whoever parses it at the far end, and there are two sets. Ordinary programs are parsed by CommandLineToArgvW, where a literal quote is written \". cmd.exe is not: it has its own rules, in which \" is a backslash followed by the end of a quoted section. Applying the first set to the second turned cmd /c notepad "C:\...\config.kdl" into an editor being handed \"C:\...\config.kdl\", backslashes and all. So cmd /c is given the rest of the line verbatim: the caller composed a complete command with its own quoting, exactly as it composes one for sh -c, and cmd.exe is the thing that should parse it. Everything else is still quoted for CommandLineToArgvW.

Paths are mixed, and only some programs mind. slosh builds paths with / throughout, because that is what it splits and compares on. The environment supplies \, so the moment a literal is joined to a variable the result is mixed: $HOME is C:\Users\you, and the config lands at C:\Users\you/.config/slosh/config.kdl. The CRT opens that without complaint, which is why --check reported it as fine, but a GUI file dialog rejects it outright, and C-a e produced a notepad saying "Not a valid file name" about a path that unambiguously existed. Anything handed to another program now goes through sl_path_native() first, which canonicalises it and settles the separators; the internal representation is left alone.

The reference counting is also why the per-pty state is not simply freed by pty_close: two pumps, a exit watcher and the caller all reach it, and a pump blocked on a dead pipe must not be waited for: that would hang the session on the one program that misbehaves. Whoever finishes last frees.

What is different#

• No SIGWINCH. A resize is noticed by comparing the console size on a short poll timeout, which is why the client's poll() there is bounded rather than infinite.
• No fork. The session daemon is started as a fresh detached process that reconstructs its arguments on the command line (--server), rather than as a copy of the process that asked for it.
• No process groups on a pty, so "what is this pane running" is answered with the most recently started descendant of the pane's shell: the process tcgetpgrp() would have named. Windows offers the image name rather than a full argv without reading another process's memory, so pane titles are correspondingly shorter.
• No VEOF, so Ctrl-D is made to mean something. The console driver has no EOF character: ^D reaches cmd.exe and PowerShell as an ordinary keystroke and they ignore it, so the key that closes a pane on every other platform does nothing at all. ctrl_d_exits (on by default here, off elsewhere) sends the shell the word exit instead, which is what you would have typed, and what makes the pane end through the shell's own cleanup and exit status rather than by being closed from outside. It stays out of the way unless all three hold: the shell itself in the foreground, the primary screen, and an empty line. A program that is running may want the EOF itself; in an editor or a pager ^D is half a page down; and a line with something on it is not an EOF anywhere.
• No editor is guaranteed. C-a e prefers whichever console editor is actually installed (nvim, vim, vi, nano, micro, hx, edit), because notepad is a GUI program: a pane running it draws nothing and looks broken. Microsoft Edit (edit) ships from Windows 11 24H2 and fills a pane like any other editor; it comes last because it arrives on its own, and so says nothing about what you want. If nothing is found, slosh still opens notepad, and says so, rather than leaving an empty pane to puzzle over. EDITOR and the config's editor are honoured ahead of the search.
• --check, --dump-config, layouts, workspaces and shaders are unaffected: they never touched a pty or a socket.