job: Add options to spawn jobs connected to pseudo terminals

CMakeLists.txt

@@ -306,6 +306,8 @@ if(BUSTED_PRG)
       -P ${PROJECT_SOURCE_DIR}/cmake/RunTests.cmake
     DEPENDS nvim-test unittest-headers)
 
+  add_subdirectory(test/functional/job) # compile pty test program
+
   add_custom_target(functionaltest
     COMMAND ${CMAKE_COMMAND}
       -DBUSTED_PRG=${BUSTED_PRG}

src/nvim/CMakeLists.txt

@@ -175,6 +175,7 @@ list(APPEND NVIM_LINK_LIBRARIES
     ${LIBTERMKEY_LIBRARIES}
     ${LIBUNIBILIUM_LIBRARIES}
     m
+    util
     ${CMAKE_THREAD_LIBS_INIT}
     )
 

src/nvim/eval.c

@@ -6489,7 +6489,7 @@ static struct fst {
   {"islocked",        1, 1, f_islocked},
   {"items",           1, 1, f_items},
   {"jobsend",         2, 2, f_jobsend},
-  {"jobstart",        2, 3, f_jobstart},
+  {"jobstart",        2, 4, f_jobstart},
   {"jobstop",         1, 1, f_jobstop},
   {"join",            1, 2, f_join},
   {"keys",            1, 1, f_keys},
@@ -10682,8 +10682,7 @@ static void f_jobstart(typval_T *argvars, typval_T *rettv)
 
   if (argvars[0].v_type != VAR_STRING
       || argvars[1].v_type != VAR_STRING
-      || (argvars[2].v_type != VAR_LIST
-      && argvars[2].v_type != VAR_UNKNOWN)) {
+      || (argvars[2].v_type != VAR_LIST && argvars[2].v_type != VAR_UNKNOWN)) {
     // Wrong argument types
     EMSG(_(e_invarg));
     return;
@@ -10731,6 +10730,24 @@ static void f_jobstart(typval_T *argvars, typval_T *rettv)
   opts.stdout_cb = on_job_stdout;
   opts.stderr_cb = on_job_stderr;
   opts.exit_cb = on_job_exit;
+
+  if (argvars[3].v_type == VAR_DICT) {
+    dict_T *job_opts = argvars[3].vval.v_dict;
+    opts.pty = true;
+    uint16_t width = get_dict_number(job_opts, (uint8_t *)"width");
+    if (width > 0) {
+      opts.width = width;
+    }
+    uint16_t height = get_dict_number(job_opts, (uint8_t *)"height");
+    if (height > 0) {
+      opts.height = height;
+    }
+    char *term = (char *)get_dict_string(job_opts, (uint8_t *)"TERM", true);
+    if (term) {
+      opts.term_name = term;
+    }
+  }
+
   job_start(opts, &rettv->vval.v_number);
 
   if (rettv->vval.v_number <= 0) {

src/nvim/os/job_defs.h

@@ -37,6 +37,13 @@ typedef struct {
   job_exit_cb exit_cb;
   // Maximum memory used by the job's WStream
   size_t maxmem;
+  // Connect the job to a pseudo terminal
+  bool pty;
+  // Initial window dimensions if the job is connected to a pseudo terminal
+  uint16_t width, height;
+  // Value for the $TERM environment variable. A default value of "ansi" is
+  // assumed if NULL
+  char *term_name;
 } JobOptions;
 
 #define JOB_OPTIONS_INIT ((JobOptions) {                     \
@@ -46,6 +53,10 @@ typedef struct {
     .stdout_cb = NULL,                                       \
     .stderr_cb = NULL,                                       \
     .exit_cb = NULL,                                         \
-    .maxmem = 0                                              \
+    .maxmem = 0,                                             \
+    .pty = false,                                            \
+    .width = 80,                                             \
+    .height = 24,                                            \
+    .term_name = NULL                                        \
     })
 #endif  // NVIM_OS_JOB_DEFS_H

src/nvim/os/job_private.h

@@ -8,6 +8,7 @@
 #include "nvim/os/rstream_defs.h"
 #include "nvim/os/wstream_defs.h"
 #include "nvim/os/pipe_process.h"
+#include "nvim/os/pty_process.h"
 #include "nvim/os/shell.h"
 #include "nvim/log.h"
 
@@ -43,22 +44,34 @@ extern uv_timer_t job_stop_timer;
 
 static inline bool process_spawn(Job *job)
 {
-  return pipe_process_spawn(job);
+  return job->opts.pty ? pty_process_spawn(job) : pipe_process_spawn(job);
 }
 
 static inline void process_init(Job *job)
 {
-  pipe_process_init(job);
+  if (job->opts.pty) {
+    pty_process_init(job);
+  } else {
+    pipe_process_init(job);
+  }
 }
 
 static inline void process_close(Job *job)
 {
-  pipe_process_close(job);
+  if (job->opts.pty) {
+    pty_process_close(job);
+  } else {
+    pipe_process_close(job);
+  }
 }
 
 static inline void process_destroy(Job *job)
 {
-  pipe_process_destroy(job);
+  if (job->opts.pty) {
+    pty_process_destroy(job);
+  } else {
+    pipe_process_destroy(job);
+  }
 }
 
 static inline void job_exit_callback(Job *job)

src/nvim/os/pty_process.c

@@ -0,0 +1,200 @@
+// Some of the code came from st(http://st.suckless.org/) and libuv
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <unistd.h>
+#include <termios.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+// openpty is not in POSIX, so headers are platform-specific
+#if defined(__linux)
+  #include <pty.h>
+#elif defined(__OpenBSD__) || defined(__NetBSD__) || defined(__APPLE__)
+  #include <util.h>
+#elif defined(__FreeBSD__) || defined(__DragonFly__)
+  #include <libutil.h>
+#endif
+
+#include <uv.h>
+
+#include "nvim/os/uv_helpers.h"
+#include "nvim/os/job.h"
+#include "nvim/os/job_defs.h"
+#include "nvim/os/job_private.h"
+#include "nvim/os/pty_process.h"
+#include "nvim/memory.h"
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "os/pty_process.c.generated.h"
+#endif
+
+typedef struct {
+  struct winsize winsize;
+  uv_pipe_t proc_stdin, proc_stdout, proc_stderr;
+  uv_signal_t schld;
+} PtyProcess;
+
+void pty_process_init(Job *job)
+{
+  PtyProcess *ptyproc = xmalloc(sizeof(PtyProcess));
+
+  if (job->opts.writable) {
+    uv_pipe_init(uv_default_loop(), &ptyproc->proc_stdin, 0);
+    ptyproc->proc_stdin.data = NULL;
+  }
+
+  if (job->opts.stdout_cb) {
+    uv_pipe_init(uv_default_loop(), &ptyproc->proc_stdout, 0);
+    ptyproc->proc_stdout.data = NULL;
+  }
+
+  if (job->opts.stderr_cb) {
+    uv_pipe_init(uv_default_loop(), &ptyproc->proc_stderr, 0);
+    ptyproc->proc_stderr.data = NULL;
+  }
+
+  job->proc_stdin = (uv_stream_t *)&ptyproc->proc_stdin;
+  job->proc_stdout = (uv_stream_t *)&ptyproc->proc_stdout;
+  job->proc_stderr = (uv_stream_t *)&ptyproc->proc_stderr;
+  job->process = ptyproc;
+}
+
+void pty_process_destroy(Job *job)
+{
+  free(job->opts.term_name);
+  free(job->process);
+  job->process = NULL;
+}
+
+bool pty_process_spawn(Job *job)
+{
+  int master, slave;
+  PtyProcess *ptyproc = job->process;
+  ptyproc->winsize = (struct winsize){job->opts.height, job->opts.width, 0, 0};
+
+  if (openpty(&master, &slave, NULL, NULL, &ptyproc->winsize)) {
+    return false;
+  }
+
+  int pid = fork();
+
+  if (pid < 0) {
+    return false;
+  } else if (pid == 0) {
+    close(master);
+    init_child(job, slave);
+    abort();
+  }
+
+  close(slave);
+  // make sure the master file descriptor is non blocking
+  fcntl(master, F_SETFL, fcntl(master, F_GETFL) | O_NONBLOCK);
+
+  if (job->opts.writable) {
+    uv_pipe_open(&ptyproc->proc_stdin, dup(master));
+  }
+
+  if (job->opts.stdout_cb) {
+    uv_pipe_open(&ptyproc->proc_stdout, dup(master));
+  }
+
+  if (job->opts.stderr_cb) {
+    uv_pipe_open(&ptyproc->proc_stderr, dup(master));
+  }
+
+  close(master);
+  uv_signal_init(uv_default_loop(), &ptyproc->schld);
+  uv_signal_start(&ptyproc->schld, chld_handler, SIGCHLD);
+  ptyproc->schld.data = job;
+  job->pid = pid;
+  return true;
+}
+
+void pty_process_close(Job *job)
+{
+  job_close_streams(job);
+  job_decref(job);
+}
+
+static void init_child(Job *job, int slave)
+{
+  // child, become session leader
+  setsid();
+  // close stdin/stdout/stderr
+  close(STDIN_FILENO);
+  close(STDOUT_FILENO);
+  close(STDERR_FILENO);
+  // and reopen connected to the slave side of the pty or to /dev/null if
+  // it should be ignored
+  if (job->opts.writable) {
+    dup(slave);
+  } else {
+    open("/dev/null", O_RDONLY);
+  }
+  if (job->opts.stdout_cb) {
+    dup(slave);
+  } else {
+    open("/dev/null", O_RDWR);
+  }
+  if (job->opts.stderr_cb) {
+    dup(slave);
+  } else {
+    open("/dev/null", O_RDWR);
+  }
+
+  if (ioctl(slave, TIOCSCTTY, NULL) < 0) {
+    fprintf(stderr, "ioctl TIOCSTTY failed: %s\n", strerror(errno));
+    abort();
+  }
+
+  close(slave);
+  // Call uv_close on every active handle
+  uv_walk(uv_default_loop(), walk_cb, NULL);
+  // Run the event loop until all handles are successfully closed
+  while (uv_loop_close(uv_default_loop())) {
+    uv_run(uv_default_loop(), UV_RUN_ONCE);
+  }
+
+  unsetenv("COLUMNS");
+  unsetenv("LINES");
+  unsetenv("TERMCAP");
+  unsetenv("COLORTERM");
+  unsetenv("COLORFGBG");
+
+  signal(SIGCHLD, SIG_DFL);
+  signal(SIGHUP, SIG_DFL);
+  signal(SIGINT, SIG_DFL);
+  signal(SIGQUIT, SIG_DFL);
+  signal(SIGTERM, SIG_DFL);
+  signal(SIGALRM, SIG_DFL);
+
+  setenv("TERM", job->opts.term_name ? job->opts.term_name : "ansi", 1);
+  execvp(job->opts.argv[0], job->opts.argv);
+  fprintf(stderr, "execvp failed: %s\n", strerror(errno));
+  abort();
+}
+
+static void walk_cb(uv_handle_t *handle, void *arg) {
+  if (!uv_is_closing(handle)) {
+    uv_close(handle, NULL);
+  }
+}
+
+static void chld_handler(uv_signal_t *handle, int signum)
+{
+  Job *job = handle->data;
+  int stat = 0;
+
+  if (waitpid(job->pid, &stat, 0) < 0) {
+    fprintf(stderr, "Waiting for pid %d failed: %s\n", job->pid,
+        strerror(errno));
+    return;
+  }
+
+  if (WIFEXITED(stat)) {
+    job->status = WEXITSTATUS(stat);
+    pty_process_close(job);
+  }
+}

src/nvim/os/pty_process.h

@@ -0,0 +1,7 @@
+#ifndef NVIM_OS_PTY_PROCESS_H
+#define NVIM_OS_PTY_PROCESS_H
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "os/pty_process.h.generated.h"
+#endif
+#endif  // NVIM_OS_PTY_PROCESS_H

test/functional/job/CMakeLists.txt

@@ -0,0 +1,2 @@
+add_executable(tty-test tty-test.c)
+target_link_libraries(tty-test ${LIBUV_LIBRARIES})

test/functional/job/job_spec.lua

@@ -115,4 +115,36 @@ describe('jobs', function()
     eq({'notification', 'j', {{jobid, 'stdout', {'abcdef'}}}}, next_message())
     eq({'notification', 'j', {{jobid, 'exit'}}}, next_message())
   end)
+
+  describe('running tty-test program', function()
+    local function next_chunk()
+      local msg = next_message()
+      local data = msg[3][1]
+      for i = 1, #data do
+        data[i] = data[i]:gsub('\n', '\000')
+      end
+      return table.concat(data, '\n')
+    end
+
+    local function send(str)
+      nvim('command', 'call jobsend(j, "'..str..'")')
+    end
+
+    before_each(function() 
+      nvim('command', notify_str('v:job_data[1]', 'get(v:job_data, 2)'))
+    end)
+
+    it('ok when pty options are passed', function()
+      nvim('command', "let j = jobstart('xxx', 'build/bin/tty-test', [], {})")
+      eq('tty ready\r', next_chunk())
+      send('test')
+      -- the tty driver will echo input by default
+      eq('test', next_chunk())
+      send('\\<c-c>')
+      eq('^Cinterrupt received, press again to exit\r', next_chunk())
+      send('\\<c-c>')
+      eq('^Ctty done\r', next_chunk())
+      eq({'notification', 'exit', {0}}, next_message())
+    end)
+  end)
 end)