Initial project import

tools/v/vlib/os/process_nix.c.v

@@ -0,0 +1,185 @@
+module os
+
+fn C.setpgid(pid i32, pgid i32) i32
+
+fn env_value_from_entries(env []string, name string) ?string {
+	prefix := '${name}='
+	for entry in env {
+		if entry.starts_with(prefix) {
+			return entry[prefix.len..]
+		}
+	}
+	return none
+}
+
+fn (p &Process) unix_resolve_filename() !string {
+	if is_abs_path(p.filename) {
+		return p.filename
+	}
+	if p.filename.contains(path_separator) {
+		if p.work_folder != '' {
+			return abs_path(p.filename)
+		}
+		return p.filename
+	}
+	path := env_value_from_entries(p.env, 'PATH') or { return error_failed_to_find_executable() }
+	return find_abs_path_of_executable_in_path_env(p.filename, path)
+}
+
+fn (mut p Process) unix_spawn_process() int {
+	mut pipeset := [6]int{}
+	if p.use_stdio_ctl {
+		mut dont_care := C.pipe(&pipeset[0]) // pipe read end 0 <- 1 pipe write end
+		dont_care = C.pipe(&pipeset[2]) // pipe read end 2 <- 3 pipe write end
+		dont_care = C.pipe(&pipeset[4]) // pipe read end 4 <- 5 pipe write end
+		_ = dont_care // using `_` directly on each above `pipe` fails to avoid C compiler generate an `-Wunused-result` warning
+	}
+	pid := fork()
+	if pid != 0 {
+		// This is the parent process after the fork.
+		// Note: pid contains the process ID of the child process
+		if p.use_stdio_ctl {
+			p.stdio_fd[0] = pipeset[1] // store the write end of child's in
+			p.stdio_fd[1] = pipeset[2] // store the read end of child's out
+			p.stdio_fd[2] = pipeset[4] // store the read end of child's err
+			// close the rest of the pipe fds, the parent does not need them
+			fd_close(pipeset[0])
+			fd_close(pipeset[3])
+			fd_close(pipeset[5])
+		}
+		return pid
+	}
+	//
+	// Here, we are in the child process.
+	// It still shares file descriptors with the parent process,
+	// but it is otherwise independent and can do stuff *without*
+	// affecting the parent process.
+	//
+	if p.use_pgroup {
+		C.setpgid(0, 0)
+	}
+	if p.use_stdio_ctl {
+		// Redirect the child standard in/out/err to the pipes that
+		// were created in the parent.
+		// Close the parent's pipe fds, the child do not need them:
+		fd_close(pipeset[1])
+		fd_close(pipeset[2])
+		fd_close(pipeset[4])
+		// redirect the pipe fds to the child's in/out/err fds:
+		C.dup2(pipeset[0], 0)
+		C.dup2(pipeset[3], 1)
+		C.dup2(pipeset[5], 2)
+		// close the pipe fdsx after the redirection
+		fd_close(pipeset[0])
+		fd_close(pipeset[3])
+		fd_close(pipeset[5])
+	}
+	p.filename = p.unix_resolve_filename() or {
+		eprintln(err)
+		exit(1)
+	}
+	if p.work_folder != '' {
+		chdir(p.work_folder) or {}
+	}
+	execve(p.filename, p.args, p.env) or {
+		eprintln(err)
+		exit(1)
+	}
+	return 0
+}
+
+fn (mut p Process) unix_stop_process() {
+	C.kill(p.pid, C.SIGSTOP)
+}
+
+fn (mut p Process) unix_resume_process() {
+	C.kill(p.pid, C.SIGCONT)
+}
+
+fn (mut p Process) unix_term_process() {
+	C.kill(p.pid, C.SIGTERM)
+}
+
+fn (mut p Process) unix_kill_process() {
+	C.kill(p.pid, C.SIGKILL)
+}
+
+fn (mut p Process) unix_kill_pgroup() {
+	C.kill(-p.pid, C.SIGKILL)
+}
+
+fn (mut p Process) unix_wait() {
+	p.impl_check_pid_status(false, 0)
+}
+
+fn (mut p Process) unix_is_alive() bool {
+	return p.impl_check_pid_status(true, C.WNOHANG)
+}
+
+fn (mut p Process) impl_check_pid_status(exit_early_on_ret0 bool, waitpid_options int) bool {
+	mut cstatus := 0
+	mut ret := -1
+	$if !emscripten ? {
+		ret = C.waitpid(p.pid, &cstatus, waitpid_options)
+	}
+	p.code = ret
+	if ret == -1 {
+		p.err = posix_get_error_msg(C.errno)
+		return false
+	}
+	if exit_early_on_ret0 && ret == 0 {
+		return true
+	}
+	mut pret, is_signaled := posix_wait4_to_exit_status(cstatus)
+	if is_signaled {
+		p.status = .aborted
+		p.err = 'Terminated by signal ${pret:2d} (${sigint_to_signal_name(pret)})'
+		pret += 128
+	} else {
+		p.status = .exited
+	}
+	p.code = pret
+	return false
+}
+
+// these are here to make v_win.c/v.c generation work in all cases:
+fn (mut p Process) win_spawn_process() int {
+	return 0
+}
+
+fn (mut p Process) win_stop_process() {
+}
+
+fn (mut p Process) win_resume_process() {
+}
+
+fn (mut p Process) win_term_process() {
+}
+
+fn (mut p Process) win_kill_process() {
+}
+
+fn (mut p Process) win_kill_pgroup() {
+}
+
+fn (mut p Process) win_wait() {
+}
+
+fn (mut p Process) win_is_alive() bool {
+	return false
+}
+
+fn (mut p Process) win_write_string(_idx int, _s string) {
+}
+
+fn (mut p Process) win_read_string(_idx int, _maxbytes int) (string, int) {
+	return '', 0
+}
+
+fn (mut p Process) win_is_pending(_idx int) bool {
+	return false
+}
+
+fn (mut p Process) win_slurp(_idx int) string {
+	return ''
+}