spawn: add optional reaper callback, return pid_t

This will allow spawn() callers to do things when the spawned process
has terminated.

input.c

@@ -306,8 +306,8 @@ execute_binding(struct seat *seat, struct terminal *term,
             }
         }
 
-        if (!spawn(term->reaper, term->cwd, binding->aux->pipe.args,
+        if (spawn(term->reaper, term->cwd, binding->aux->pipe.args,
-                   pipe_fd[0], stdout_fd, stderr_fd, NULL))
+                  pipe_fd[0], stdout_fd, stderr_fd, NULL, NULL, NULL) < 0)
             goto pipe_err;
 
         /* Close read end */

notify.c

@@ -59,7 +59,11 @@ notify_notify(const struct terminal *term, const char *title, const char *body,
 
     /* Redirect stdin to /dev/null, but ignore failure to open */
     int devnull = open("/dev/null", O_RDONLY);
-    spawn(term->reaper, NULL, argv, devnull, -1, -1, NULL);
+    pid_t pid = spawn(
+        term->reaper, NULL, argv, devnull, stdout_fds[1], -1,
+        &notif_done, (void *)term, NULL);
+
+    if (stdout_fds[1] >= 0) {
 
     if (devnull >= 0)
         close(devnull);

spawn.c

@@ -15,9 +15,9 @@
 #include "debug.h"
 #include "xmalloc.h"
 
-bool
+pid_t
 spawn(struct reaper *reaper, const char *cwd, char *const argv[],
-      int stdin_fd, int stdout_fd, int stderr_fd,
+      int stdin_fd, int stdout_fd, int stderr_fd, reaper_cb cb, void *cb_data,
       const char *xdg_activation_token)
 {
     int pipe_fds[2] = {-1, -1};
@@ -104,16 +104,16 @@ spawn(struct reaper *reaper, const char *cwd, char *const argv[],
     close(pipe_fds[0]);
 
     if (ret == 0) {
-        reaper_add(reaper, pid, NULL, NULL);
+        reaper_add(reaper, pid, cb, cb_data);
-        return true;
+        return pid;
     } else if (ret < 0) {
         LOG_ERRNO("failed to read from pipe");
-        return false;
+        return -1;
     } else {
         LOG_ERRNO_P(errno_copy, "%s: failed to spawn", argv[0]);
         errno = errno_copy;
         waitpid(pid, NULL, 0);
-        return false;
+        return -1;
     }
 
 err:
@@ -121,7 +121,7 @@ err:
         close(pipe_fds[0]);
     if (pipe_fds[1] != -1)
         close(pipe_fds[1]);
-    return false;
+    return -1;
 }
 
 bool

spawn.h

@@ -1,12 +1,14 @@
 #pragma once
 
 #include <stdbool.h>
+#include <unistd.h>
+
 #include "config.h"
 #include "reaper.h"
 
-bool spawn(struct reaper *reaper, const char *cwd, char *const argv[],
+pid_t spawn(struct reaper *reaper, const char *cwd, char *const argv[],
-           int stdin_fd, int stdout_fd, int stderr_fd,
+            int stdin_fd, int stdout_fd, int stderr_fd,
-           const char *xdg_activation_token);
+            reaper_cb cb, void *cb_data, const char *xdg_activation_token);
 
 bool spawn_expand_template(
     const struct config_spawn_template *template,

terminal.c

@@ -198,7 +198,7 @@ add_utmp_record(const struct config *conf, struct reaper *reaper, int ptmx)
         return true;
 
     char *const argv[] = {conf->utmp_helper_path, UTMP_ADD, getenv("WAYLAND_DISPLAY"), NULL};
-    return spawn(reaper, NULL, argv, ptmx, ptmx, -1, NULL);
+    return spawn(reaper, NULL, argv, ptmx, ptmx, -1, NULL, NULL, NULL) >= 0;
 #else
     return true;
 #endif
@@ -222,7 +222,7 @@ del_utmp_record(const struct config *conf, struct reaper *reaper, int ptmx)
         ;
 
     char *const argv[] = {conf->utmp_helper_path, UTMP_DEL, del_argument, NULL};
-    return spawn(reaper, NULL, argv, ptmx, ptmx, -1, NULL);
+    return spawn(reaper, NULL, argv, ptmx, ptmx, -1, NULL, NULL, NULL) >= 0;
 #else
     return true;
 #endif
@@ -3594,7 +3594,7 @@ term_bell(struct terminal *term)
     {
         int devnull = open("/dev/null", O_RDONLY);
         spawn(term->reaper, NULL, term->conf->bell.command.argv.args,
-              devnull, -1, -1, NULL);
+              devnull, -1, -1, NULL, NULL, NULL);
 
         if (devnull >= 0)
             close(devnull);
@@ -3606,7 +3606,7 @@ term_spawn_new(const struct terminal *term)
 {
     return spawn(
         term->reaper, term->cwd, (char *const []){term->foot_exe, NULL},
-        -1, -1, -1, NULL);
+        -1, -1, -1, NULL, NULL, NULL) >= 0;
 }
 
 void

url-mode.c

@@ -74,8 +74,9 @@ spawn_url_launcher_with_token(struct terminal *term,
             (const char *[]){url},
             &argc, &argv))
     {
-        ret = spawn(term->reaper, term->cwd, argv,
+        ret = spawn(
-              dev_null, dev_null, dev_null, xdg_activation_token);
+            term->reaper, term->cwd, argv,
+            dev_null, dev_null, dev_null, NULL, NULL, xdg_activation_token) >= 0;
 
         for (size_t i = 0; i < argc; i++)
             free(argv[i]);