Processes & PTYs

Spawn and drive child processes with streaming I/O. Unlike shell (which blocks and returns output only after the process exits), these hand you a live handle you poll. All require the PROCESS capability (see System).

Streaming processes

proc/* streams a child's output into pollable buffers, so you can show output as it happens.

(define p (proc/spawn ["cargo" "test"] {:cwd "."}))
(let loop ()
  (let ((out (proc/read-stdout p)))
    (when (not (= out "")) (io/print-error out))
    (when (proc/running? p) (sleep 50) (loop))))
(define code (proc/wait p))           ; exit code; flushes the tail first
(proc/close p)                        ; free the handle

Full set: proc/spawn, proc/read-stdout, proc/read-stderr, proc/write-stdin, proc/close-stdin, proc/wait, proc/exit-code, proc/running?, proc/kill, proc/close.

Pseudo-terminals

Like proc/*, but the child runs under a real PTY, so programs that probe isatty (REPLs, editors, top, color-aware tools) behave normally.

(define t (pty/spawn ["bash"] {:rows 40 :cols 120}))
(pty/write t "ls -la\n")
(sleep 100)
(io/print-error (pty/read t))         ; output incl. control sequences
(pty/resize t 50 200)                 ; delivers SIGWINCH
(pty/kill t)
(pty/close t)

Full set: pty/spawn, pty/read, pty/write, pty/resize, pty/wait, pty/exit-code, pty/running?, pty/kill, pty/close.