Further improve XLib code and include go code capable of calling it

xdg/get-x-slave-devnodes/Makefile

@@ -1,5 +0,0 @@
-get-x-slave-devnodes: get-x-slave-devnodes.c
-	$(CC) -O2 --std=gnu99 -pedantic -Wall get-x-slave-devnodes.c -o get-x-slave-devnodes -lX11 -lXi
-clean:
-	rm -f get-x-slave-devnodes
-

xdg/xinput_devnodes/Makefile

@@ -0,0 +1,5 @@
+main: main.c
+	$(CC) -O2 --std=gnu99 -pedantic -Wall main.c xslaves.c devnodes.c -o devnodes -lX11 -lXi
+clean:
+	rm -f devnodes
+

xdg/xinput_devnodes/devnodes.c

@@ -8,11 +8,13 @@
 
 #define _GNU_SOURCE
 
-#include <string.h>
-#include <stdio.h>
+#include "devnodes.h"
+
 #include <stdlib.h>
+#include <stdio.h>
 #include <stdint.h>
 #include <stdbool.h>
+#include <string.h>
 
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
@@ -73,6 +75,42 @@ char* get_property_xi2(Display* dpy, int deviceid, Atom property, const char* pr
     return ret;
 }
 
+XSlaves* build_slave_info(Display* disp)
+{
+	int num_slaves;
+	XIDeviceInfo* all_slaves = XIQueryDevice(disp, XIAllDevices, &num_slaves);
+    XSlaves* slaves = new_xslaves(num_slaves);
+    bool fail = false;
+
+	for (int i = 0; i < num_slaves; i++)
+	{
+		XIDeviceInfo* current_slave = &all_slaves[i];
+        int nprops;
+        Atom* props = XIListProperties(disp, current_slave->deviceid, &nprops);
+
+        while(nprops-- && !fail)
+        {
+            char* devnode = get_property_xi2(disp, current_slave->deviceid, props[nprops], "Device Node");
+            if (current_slave->name != NULL && devnode != NULL)
+            {
+                int success = add_slaveinfo(slaves, current_slave->name, devnode);
+                if (success != 0)
+                    fail = true;
+            }
+            free(devnode);
+        }
+        XFree(props);
+        if (fail)
+        {
+            free_xslaves(slaves);
+            break;
+        }
+
+	}
+	XIFreeDeviceInfo(all_slaves);
+    return slaves;
+}
+
 int is_xinput2_available(Display* disp)
 {
     int xiOpcode;
@@ -99,103 +137,6 @@ int is_xinput2_available(Display* disp)
     return 0;
 }
 
-typedef struct SlaveInfo
-{
-    char* slave_names;
-    char* dev_nodes;
-} SlaveInfo;
-
-SlaveInfo new_slave_info()
-{
-    SlaveInfo si;
-    si.slave_names = NULL;
-    si.dev_nodes = NULL;
-    return si;
-}
-
-void free_slave_info(SlaveInfo si)
-{
-    free(si.slave_names);
-    free(si.dev_nodes);
-    si.slave_names = NULL;
-    si.dev_nodes = NULL;
-}
-
-bool is_empty_slave_info(SlaveInfo si)
-{
-    return (si.slave_names == NULL || si.dev_nodes == NULL);
-}
-
-void replace(char* str, char old, char new)
-{
-    int i = 0;
-    while (str[i] != '\0')
-    {
-        if (str[i] == old)
-            str[i] = new;
-        i++;
-    }
-}
-
-int append_as_line(char** dst, char* line)
-{
-    uint len_newstr = strlen(line) + 2;
-    if (*dst != NULL)
-        len_newstr += strlen(*dst);
-
-    char* newstr = (char*)malloc(len_newstr);
-    if (newstr == NULL)
-        return -1;
-
-    newstr[0] = '\0';
-    replace(line, '\n', ' ');
-    if (*dst != NULL)
-        strcat(newstr, *dst);
-    strcat(newstr, line);
-    strcat(newstr, "\n");
-
-    free(*dst);
-    *dst = newstr;
-    return 0;
-}
-
-SlaveInfo get_slave_info(Display* disp)
-{
-	int num_slaves;
-	XIDeviceInfo* all_slaves = XIQueryDevice(disp, XIAllDevices, &num_slaves);
-    SlaveInfo slaveinfo = new_slave_info();
-    bool fail = false;
-
-	for (int i = 0; i < num_slaves; i++)
-	{
-		XIDeviceInfo* current_slave = &all_slaves[i];
-        int nprops;
-        Atom* props = XIListProperties(disp, current_slave->deviceid, &nprops);
-
-        while(nprops-- && !fail)
-        {
-            char* devnode = get_property_xi2(disp, current_slave->deviceid, props[nprops], "Device Node");
-            if (current_slave->name != NULL && devnode != NULL)
-            {
-                int append_slave_success = append_as_line(&slaveinfo.slave_names, current_slave->name);
-                int append_devnode_success = append_as_line(&slaveinfo.dev_nodes, devnode);
-                if (append_slave_success != 0 || append_devnode_success != 0)
-                    fail = true;
-            }
-            free(devnode);
-        }
-        XFree(props);
-        if (fail)
-        {
-            free_slave_info(slaveinfo);
-            break;
-        }
-
-	}
-	XIFreeDeviceInfo(all_slaves);
-    return slaveinfo;
-}
-
 Display* connect_to_x(const char* xDisplayName)
 {
     Display* disp = XOpenDisplay(xDisplayName);
@@ -214,8 +155,7 @@ Display* connect_to_x(const char* xDisplayName)
     return disp;
 }
 
-
-int main(int argc, char * argv[])
+XSlaves* get_slave_info()
 {
     char* xDisplayName = getenv("DISPLAY");
     if (xDisplayName == NULL)
@@ -228,14 +168,21 @@ int main(int argc, char * argv[])
     if (disp == NULL)
         exit(1);
 
-    SlaveInfo si = get_slave_info(disp);
-    if (!is_empty_slave_info(si))
-    {
-        printf("%s", si.slave_names);
-        printf("%s", si.dev_nodes);
-    }
-
-    free_slave_info(si);
+    XSlaves* s = build_slave_info(disp);
     XCloseDisplay(disp);
-    exit(0);
+    return s;
 }
+
+
+// int main(int argc, char * argv[])
+// {
+//     XSlaves* s = get_slave_info();
+//     for (int i = 0; i < s->length; i++)
+//     {
+//         XSlaveInfo si = s->slaves[i];
+//         printf("Name: %s\n", si.name);
+//         printf("Node: %s\n", si.dev_node);
+//         printf("\n");
+//     }
+//     free_xslaves(s);
+// }

xdg/xinput_devnodes/devnodes.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#include "xslaves.h"
+
+
+XSlaves* get_slave_info();

xdg/xinput_devnodes/main.c

@@ -0,0 +1,16 @@
+#include "devnodes.h"
+#include "xslaves.h"
+
+#include <stdio.h>
+
+
+int main(int argc, char** argv) {
+    XSlaves* xs = get_slave_info();
+    for (int i=0; i < xs->length; i++)
+    {
+        XSlaveInfo si = xs->slaves[i];
+        printf("%s = %s\n", si.name, si.dev_node);
+    }
+
+    free_xslaves(xs);
+}

xdg/xinput_devnodes/xinput_devnodes.go

@@ -0,0 +1,51 @@
+package xinput_devnodes
+
+// #cgo CFLAGS: -g --std=gnu99 -pedantic -Wall
+// #cgo LDFLAGS: -lX11 -lXi 
+// #include "devnodes.h"
+// #include <stdlib.h>
+// #include <string.h>
+import "C"
+import (
+	"fmt"
+	"unsafe"
+	"regexp"
+)
+
+
+func FindKeyboardDevNode() string {
+	xslaveinfos, freeMethod := GetXSlaveInfo()
+	defer freeMethod()
+
+	re := regexp.MustCompile(`(?i).*keyboard.*`)
+	for _, xslaveinfo := range xslaveinfos {
+		name, devNode := C.GoString(xslaveinfo.name), C.GoString(xslaveinfo.dev_node)
+		if re.MatchString(name) {
+			return devNode
+		}
+	}
+	return ""
+}
+
+
+func Print() {
+	xslaveinfos, freeMethod := GetXSlaveInfo()
+	defer freeMethod()
+
+	for _, xslaveinfo := range xslaveinfos {
+		fmt.Printf("%s = %s\n", C.GoString(xslaveinfo.name), C.GoString(xslaveinfo.dev_node))
+	}
+}
+
+
+func GetXSlaveInfo() ([]C.XSlaveInfo, func()) {
+	xslaves := C.get_slave_info()
+	arr := (*[1 << 30]C.XSlaveInfo)(unsafe.Pointer(xslaves.slaves))
+	slice := arr[:xslaves.length:xslaves.length]
+	freeMethod := func() {
+		C.free_xslaves(xslaves)
+	}
+
+	return slice, freeMethod
+}
+

xdg/xinput_devnodes/xslaves.c

@@ -0,0 +1,55 @@
+#include "xslaves.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+
+XSlaveInfo new_slave_info()
+{
+    XSlaveInfo si;
+    si.name = NULL;
+    si.dev_node = NULL;
+    return si;
+}
+
+void free_slave_info(XSlaveInfo si)
+{
+    free(si.name);
+    free(si.dev_node);
+    si.name = NULL;
+    si.dev_node = NULL;
+}
+
+XSlaves* new_xslaves(size_t capacity)
+{
+    XSlaves* s = (XSlaves*)malloc(sizeof(XSlaves));
+    s->capacity = capacity;
+    s->length = 0;
+    s->slaves = (XSlaveInfo*)malloc(capacity*sizeof(XSlaveInfo));
+    return s;
+}
+
+void free_xslaves(XSlaves* slaves)
+{
+    for (int i = 0; i < slaves->length; i++)
+        free_slave_info(slaves->slaves[i]);
+    free(slaves->slaves);
+    slaves->slaves = NULL;
+    slaves->length = 0;
+    slaves->capacity = 0;
+    free(slaves);
+}
+
+int add_slaveinfo(XSlaves* slaves, char* name, char* dev_node)
+{
+    XSlaveInfo si = new_slave_info();
+    si.name = strdup(name);
+    si.dev_node = strdup(dev_node);
+    if (slaves->length < slaves->capacity)
+    {
+        slaves->slaves[slaves->length] = si;
+        slaves->length++;
+        return 0;
+    }
+    return -1;
+}

xdg/xinput_devnodes/xslaves.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <stddef.h>
+
+
+typedef struct XSlaveInfo
+{
+    char* name;
+    char* dev_node;
+} XSlaveInfo;
+
+typedef struct XSalves
+{
+    XSlaveInfo* slaves;
+    size_t capacity;
+    size_t length;
+} XSlaves;
+
+
+XSlaveInfo new_slave_info();
+void free_slave_info(XSlaveInfo si);
+
+XSlaves* new_xslaves(size_t capacity);
+void free_xslaves(XSlaves* slaves);
+int add_slaveinfo(XSlaves* slaves, char* name, char* dev_node);