Added code. It should work.

Makefile

@@ -0,0 +1,5 @@
+LDFLAGS=-lasound -lX11 -lXtst -Wall
+
+mid2key: mid2key.c
+clean: 
+	rm -f mid2key

mid2key.c

@@ -0,0 +1,111 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <wordexp.h>
+
+#include <alsa/seq_event.h>
+#include <alsa/seq_midi_event.h>
+#include <X11/Xlib.h>
+#include <X11/extensions/XTest.h>
+
+int main(int argc, char** argv)
+{
+    /*defines*/
+    Display* xdp;
+    FILE* midi;
+    FILE* config;
+    const char* file;
+    KeyCode map[128];
+    char buffer[128];
+    char* keysym;
+    int temp;
+    snd_midi_event_t* parser;
+    snd_seq_event_t event;
+    wordexp_t file_expanded;
+
+    /*usage*/
+    if ((argc != 2) && (argc != 3)) {
+        fprintf(stderr,"Usage: %s device [config]\n"
+                       "Defaults to ~/.mid2key if config is unspecified.\n"
+                       "Configuration example:\n"
+                       "#set note #32 to spacebar\n"
+                       "32=space\n"
+                       "#set note #33 to keycode 67\n"
+                       "33=67\n"
+                       "#leave note #34 unset\n"
+                       "34=\n"
+                       "#also set note 35 to space\n"
+                       "35=space\n"
+                ,*argv);
+        return 1;
+    }
+
+    /*display*/
+    if (!(xdp = XOpenDisplay(getenv("DISPLAY")))) {
+        fputs("Unable to open X display.",stderr);
+        return 2;
+    }
+
+    /*config*/
+    if (argc == 3) {
+        file = argv[2];
+    } else {
+        file = "~/.mid2key";
+    }
+    wordexp(file, &file_expanded, 0);
+    memset(map,0,sizeof(map));
+    if (!(config = fopen(file_expanded.we_wordv[0],"r"))) {
+        fprintf(stderr,"Unable to open configuration file '%s'\nUsing null mapping.\n",file);
+    } else {
+        while (fgets(buffer,128,config)) {
+            if (*buffer != '#') {
+                if ((keysym = strchr(buffer,'='))) {
+                    temp = atoi(buffer);
+                    if ((temp >= 0) && (temp <= 127)) {
+                        ++keysym;
+                        if (strchr(keysym,'\n')) *strchr(keysym,'\n') = '\0';
+                        if ((map[temp] = XStringToKeysym(keysym))) {
+                            if (!(map[temp] = XKeysymToKeycode(xdp,map[temp])))
+                                fprintf(stderr,"No keycode for keysym '%s'\n",keysym);
+                        } else if (*keysym) {
+                            fprintf(stderr,"Undefined keysym '%s'\n",keysym);
+                        }
+                    }
+                }
+            }
+        }
+        fclose(config);
+    }
+
+    /*midi*/
+    if (!(midi = fopen(argv[1],"rb"))) {
+        fprintf(stderr,"Unable to open MIDI device '%s'\n",argv[1]);
+        XCloseDisplay(xdp);
+        return 3;
+    }
+    snd_midi_event_new(32,&parser);
+    /*feed implied note on message*/
+    snd_midi_event_encode_byte(parser,0x9A,&event);
+
+    /*main loop*/
+    fputs("Ready for midi input\n",stderr);
+    while ((temp = fgetc(midi)) != EOF) {
+        if (snd_midi_event_encode_byte(parser, temp, &event) == 1) {
+            if (event.type == SND_SEQ_EVENT_NOTEON) {
+                if ((event.data.note.note <= 127) && (event.data.note.velocity)) {
+                    if ((temp = map[event.data.note.note])) {
+                        XTestFakeKeyEvent(xdp,temp,1,CurrentTime);
+                        XTestFakeKeyEvent(xdp,temp,0,CurrentTime);
+                        XFlush(xdp);
+                    }
+                    printf("%i->%i\n",event.data.note.note,(int)map[event.data.note.note]);
+                }
+            }
+        }
+    }
+
+    /*cleanup*/
+    snd_midi_event_free(parser);
+    fclose(midi);
+    return 0;
+}

test

@@ -0,0 +1,15 @@
+31=v
+37=v
+34=v
+48=b
+47=n
+43=m
+33=c
+46=b
+44=
+42=b
+49=m
+91=m
+51=n
+89=n
+53=n