Integrate dmenu as a preloaded zero-lag DWM plugin (dmenu.so)

src/dwm-plugins/dwm_plugin_runner.c

@@ -1,15 +1,131 @@
 #include <dirent.h>
 #include <dlfcn.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <strings.h>
+#include <sys/socket.h>
+#include <sys/un.h>
 #include <unistd.h>
 
 #include "../sxmo-dwm/dwm_plugin.h"
 
+static int write_all(int fd, const void *buf, size_t len) {
+  const char *p = (const char *)buf;
+  while (len > 0) {
+    ssize_t n = write(fd, p, len);
+    if (n < 0) {
+      if (errno == EINTR)
+        continue;
+      return -1;
+    }
+    p += n;
+    len -= (size_t)n;
+  }
+  return 0;
+}
+
+static int is_dmenu_builtin_arg(const char *arg) {
+  if (!arg || !arg[0])
+    return 0;
+  return strcmp(arg, "sys") == 0 ||
+         strcmp(arg, "ctx") == 0 ||
+         strcmp(arg, "applications") == 0 ||
+         strcmp(arg, "scripts") == 0 ||
+         strcmp(arg, "modem") == 0 ||
+         strcmp(arg, "config") == 0 ||
+         strcmp(arg, "power") == 0 ||
+         strcmp(arg, "st") == 0 ||
+         strcmp(arg, "nano") == 0 ||
+         strcmp(arg, "sthotkeys") == 0;
+}
+
+static int try_dmenu_socket_client(int sub_argc, char **sub_argv, int *exit_code_out) {
+  FILE *pf = fopen("/tmp/dwm_plugin_dmenu.pid", "r");
+  if (!pf)
+    return 0;
+  int pid = 0;
+  int ok = (fscanf(pf, "%d", &pid) == 1 && pid > 1 && kill((pid_t)pid, 0) == 0);
+  fclose(pf);
+  if (!ok)
+    return 0;
+
+  int sock = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0);
+  if (sock < 0)
+    return 0;
+
+  struct sockaddr_un addr;
+  memset(&addr, 0, sizeof(addr));
+  addr.sun_family = AF_UNIX;
+  strncpy(addr.sun_path, "/tmp/dwm_plugin_dmenu.sock", sizeof(addr.sun_path) - 1);
+
+  if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) != 0) {
+    close(sock);
+    return 0;
+  }
+
+  uint32_t c_argc = (uint32_t)sub_argc;
+  if (write_all(sock, &c_argc, sizeof(c_argc)) != 0) {
+    close(sock);
+    return 0;
+  }
+  for (int i = 0; i < sub_argc; i++) {
+    const char *s = sub_argv[i] ? sub_argv[i] : "";
+    uint32_t slen = (uint32_t)strlen(s);
+    if (write_all(sock, &slen, sizeof(slen)) != 0 ||
+        (slen > 0 && write_all(sock, s, slen) != 0)) {
+      close(sock);
+      return 0;
+    }
+  }
+
+  char buf[4096];
+  for (;;) {
+    ssize_t n = read(STDIN_FILENO, buf, sizeof(buf));
+    if (n < 0) {
+      if (errno == EINTR)
+        continue;
+      break;
+    }
+    if (n == 0)
+      break;
+    if (write_all(sock, buf, (size_t)n) != 0) {
+      close(sock);
+      return 0;
+    }
+  }
+
+  shutdown(sock, SHUT_WR);
+
+  uint8_t status_byte = 1;
+  ssize_t first = read(sock, &status_byte, 1);
+  if (first <= 0) {
+    close(sock);
+    *exit_code_out = 1;
+    return 1;
+  }
+
+  for (;;) {
+    ssize_t n = read(sock, buf, sizeof(buf));
+    if (n < 0) {
+      if (errno == EINTR)
+        continue;
+      break;
+    }
+    if (n == 0)
+      break;
+    (void)write_all(STDOUT_FILENO, buf, (size_t)n);
+  }
+
+  close(sock);
+  *exit_code_out = (int)status_byte;
+  return 1;
+}
+
 static int try_send_plugin_fifo(const char *plugin_name, int sub_argc, char **sub_argv) {
   if (sub_argc >= 2 && sub_argv[1] && strcmp(sub_argv[1], "--preload") == 0) {
     return 0;
@@ -38,6 +154,9 @@ static int try_send_plugin_fifo(const char *plugin_name, int sub_argc, char **su
   int len = 0;
   if (strcmp(plugin_name, "xdrawer") == 0) {
     len = snprintf(cmd, sizeof(cmd), "TOGGLE\n");
+  } else if (strcmp(plugin_name, "dmenu") == 0 && sub_argc >= 2 && sub_argv[1] &&
+             strcmp(sub_argv[1], "close") == 0) {
+    len = snprintf(cmd, sizeof(cmd), "CLOSE\n");
   } else if (sub_argc >= 2 && sub_argv[1] && strcmp(sub_argv[1], "newcontact") == 0) {
     const char *num = (sub_argc >= 3 && sub_argv[2]) ? sub_argv[2] : "";
     len = snprintf(cmd, sizeof(cmd), "OPEN new:%s\n", num);
@@ -69,6 +188,9 @@ static const char *const kPluginDirs[] = {
 static const char *resolve_plugin_name_from_argv0(const char *argv0) {
   const char *base = strrchr(argv0, '/');
   base = base ? (base + 1) : argv0;
+  if (strcasecmp(base, "dmenu") == 0 || strcasecmp(base, "xdmenu") == 0) {
+    return "dmenu";
+  }
   if (strcasecmp(base, "xdrawer") == 0) {
     return "xdrawer";
   }
@@ -126,6 +248,7 @@ static int list_plugins(void) {
 }
 
 int main(int argc, char **argv) {
+  signal(SIGPIPE, SIG_IGN);
   const char *plugin_name = resolve_plugin_name_from_argv0(argv[0]);
   int sub_argc = argc;
   char **sub_argv = argv;
@@ -143,7 +266,34 @@ int main(int argc, char **argv) {
     sub_argv = argv + 1;
   }
 
-  if (try_send_plugin_fifo(plugin_name, sub_argc, sub_argv)) {
+  if (strcmp(plugin_name, "dmenu") == 0) {
+    if (sub_argc >= 2 && sub_argv[1]) {
+      if (strcmp(sub_argv[1], "-v") == 0) {
+        puts("dmenu-5.0.14-bananarchy");
+        return 0;
+      }
+      if (strcmp(sub_argv[1], "isopen") == 0) {
+        return access("/tmp/dwm_plugin_dmenu.active", F_OK) == 0 ? 0 : 1;
+      }
+      if (strcmp(sub_argv[1], "close") == 0) {
+        try_send_plugin_fifo("dmenu", sub_argc, sub_argv);
+        unlink("/tmp/dwm_plugin_dmenu.active");
+        return 0;
+      }
+      if (is_dmenu_builtin_arg(sub_argv[1])) {
+        if (try_send_plugin_fifo("dmenu", sub_argc, sub_argv)) {
+          return 0;
+        }
+      }
+    }
+    if (!(sub_argc >= 2 && sub_argv[1] &&
+          (strcmp(sub_argv[1], "--preload") == 0 || is_dmenu_builtin_arg(sub_argv[1])))) {
+      int exit_code = 1;
+      if (try_dmenu_socket_client(sub_argc, sub_argv, &exit_code)) {
+        return exit_code;
+      }
+    }
+  } else if (try_send_plugin_fifo(plugin_name, sub_argc, sub_argv)) {
     return 0;
   }