Code to read the IBUS address

glfw/ibus_glfw.c

@@ -24,6 +24,7 @@
 //
 //========================================================================
 
+#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -33,12 +34,98 @@
 static inline GLFWbool
 has_env_var(const char *name, const char *val) {
     const char *q = getenv(name);
-    return (q && strcmp(q, val)) ? GLFW_TRUE : GLFW_FALSE;
+    return (q && strcmp(q, val) == 0) ? GLFW_TRUE : GLFW_FALSE;
 }
 
+static inline GLFWbool
+MIN(size_t a, size_t b) {
+    return a < b ? a : b;
+}
+
+
+static inline const char*
+get_ibus_address_file_name(void) {
+    const char *addr;
+    static char ans[PATH_MAX];
+    addr = getenv("IBUS_ADDRESS");
+    int offset = 0;
+    if (addr && addr[0]) {
+        memcpy(ans, addr, MIN(strlen(addr), sizeof(ans)));
+        return ans;
+    }
+
+    const char *de = getenv("DISPLAY");
+    if (!de || !de[0]) de = ":0.0";
+    char *display = strdup(de);
+    const char *host = display;
+    char *disp_num  = strrchr(display, ':');
+    char *screen_num = strrchr(display, '.');
+
+    if (!disp_num) {
+        _glfwInputError(GLFW_PLATFORM_ERROR, "Could not get IBUS address file name as DISPLAY env var has no colon");
+        free(display);
+        return NULL;
+    }
+    *disp_num = 0;
+    disp_num++;
+    if (screen_num) *screen_num = 0;
+    if (!*host) host = "unix";
+
+    memset(ans, 0, sizeof(ans));
+    const char *conf_env = getenv("XDG_CONFIG_HOME");
+    if (conf_env && conf_env[0]) {
+        offset = snprintf(ans, sizeof(ans), "%s", conf_env);
+    } else {
+        conf_env = getenv("HOME");
+        if (!conf_env || !conf_env[0]) {
+            _glfwInputError(GLFW_PLATFORM_ERROR, "Could not get IBUS address file name as no HOME env var is set");
+            free(display);
+            return NULL;
+        }
+        offset = snprintf(ans, sizeof(ans), "%s/.config", conf_env);
+    }
+    char *key = dbus_get_local_machine_id();
+    snprintf(ans + offset, sizeof(ans) - offset, "/ibus/bus/%s-%s-%s", key, host, disp_num);
+    dbus_free(key);
+    free(display);
+    return ans;
+}
+
+
+static inline const char*
+read_ibus_address(const char *address_file) {
+    FILE *addr_file = fopen(address_file, "r");
+    static char buf[1024];
+    if (!addr_file) {
+        _glfwInputError(GLFW_PLATFORM_ERROR, "Failed to open IBUS address file: %s with error: %s", address_file, strerror(errno));
+        return NULL;
+    }
+    GLFWbool found = GLFW_FALSE;
+    while (fgets(buf, sizeof(buf), addr_file)) {
+        if (strncmp(buf, "IBUS_ADDRESS=", sizeof("IBUS_ADDRESS=")-1) == 0) {
+            size_t sz = strlen(buf);
+            if (buf[sz-1] == '\n') buf[sz-1] = 0;
+            if (buf[sz-2] == '\r') buf[sz-2] = 0;
+            found = GLFW_TRUE;
+            break;
+        }
+    }
+    fclose(addr_file); addr_file = NULL;
+    if (found) return buf + sizeof("IBUS_ADDRESS=") - 1;
+    _glfwInputError(GLFW_PLATFORM_ERROR, "Could not find IBUS_ADDRESS in %s", address_file);
+    return NULL;
+}
+
+
 void
 glfw_connect_to_ibus(_GLFWIBUSData *ibus, _GLFWDBUSData *dbus) {
     if (ibus->ok) return;
     if (!has_env_var("XMODIFIERS", "@im=ibus") && !has_env_var("GTK_IM_MODULE", "ibus") && !has_env_var("QT_IM_MODULE", "ibus")) return;
-    if (!glfw_dbus_init(dbus)) return;
+    if (!glfw_dbus_init(dbus)) {
+        _glfwInputError(GLFW_PLATFORM_ERROR, "Cannot connect to IBUS as connection to DBUS session bus failed");
+    }
+    const char* address_file_name = get_ibus_address_file_name();
+    if (!address_file_name) return;
+    const char *address = read_ibus_address(address_file_name);
+    if (!address) return;
 }