diff --git a/inotify/Makefile b/inotify/Makefile
new file mode 100644
index 0000000..6220e27
--- /dev/null
+++ b/inotify/Makefile
@@ -0,0 +1,8 @@
+# Makefile for sample program
+# @miura
+
+all: 
+	gcc -o show_events show_events.c
+	gcc -o exec_on_modify exec_on_modify.c
+clean:
+	rm -f exec_on_modify show_events 
diff --git a/inotify/exec_on_modify.c b/inotify/exec_on_modify.c
new file mode 100644
index 0000000..e3a1968
--- /dev/null
+++ b/inotify/exec_on_modify.c
@@ -0,0 +1,307 @@
+/**
+ * Original:
+ * https://blpr.net/?p=210
+ *
+ * 20201130 @miura added #include<unistd.h> to prevent warning of implicit declaration of functions:
+ * read / close.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <sys/inotify.h>
+#include <sys/select.h>
+#include <limits.h>
+// @miura added
+#include <unistd.h>
+#include <time.h>
+#include <sys/wait.h>
+
+#define WATCH_DIR "."
+
+//イベントサイズは16バイト境界
+#define INOTIFY_EVENT_MAX (((sizeof(struct inotify_event)+NAME_MAX+1)+16)&~16)
+
+typedef struct _WD_INFO
+{
+   struct _WD_INFO* prev;
+   struct _WD_INFO* next;
+   int wd;
+   char* path;
+} WD_INFO;
+
+static WD_INFO* topWdInfo = NULL;
+
+static void getWdInfo(int fd, char* dirname)
+{
+   DIR* dir = NULL;
+   struct dirent* entry;
+   struct stat st;
+   int wd;
+   int dirname_len;
+   int entname_len;
+   char* fullpath = NULL;
+   WD_INFO* newWdInfo;
+
+   newWdInfo = (WD_INFO*)malloc(sizeof(WD_INFO));
+
+   if(topWdInfo == NULL){
+      // first
+      topWdInfo = newWdInfo;
+      topWdInfo->prev = topWdInfo;
+      topWdInfo->next = topWdInfo;
+   }else{
+      newWdInfo->prev = topWdInfo->prev;
+      topWdInfo->prev->next = newWdInfo;
+      topWdInfo->prev = newWdInfo;
+      newWdInfo->next = topWdInfo;
+   }
+
+   newWdInfo->wd = inotify_add_watch(fd, dirname, IN_ALL_EVENTS);
+   newWdInfo->path = strdup(dirname);
+
+   //Search Sub directry
+   dir = opendir(dirname);
+
+   dirname_len = strlen(dirname);
+
+   while((entry = readdir(dir)) != NULL){
+
+      if(strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0){
+         continue;
+      }
+
+      //エントリのタイプ種別を非標準のd_typeを使わず、statで取得
+      entname_len = strlen(entry->d_name);
+      fullpath = (char*)malloc(dirname_len + 1 + entname_len + 1);
+      strcpy(fullpath, dirname);
+      strcat(fullpath, "/");
+      strcat(fullpath, entry->d_name);
+      stat(fullpath, &st);
+
+      if(S_ISDIR(st.st_mode)){
+         //再帰呼び出し
+         getWdInfo(fd, fullpath);
+      }
+
+      free(fullpath);
+   }
+
+   closedir(dir);
+}
+
+
+static char* wd2path(int wd)
+{
+   WD_INFO* p;
+
+   if(topWdInfo == NULL){
+      return NULL;
+   }
+
+   p = topWdInfo;
+   do{
+      if(p->wd == wd){
+         return p->path;
+      }
+      p = p->next;
+   }while(p != topWdInfo);
+
+   return NULL;
+}
+
+static void closeAllWdInfo(int fd)
+{
+   WD_INFO* p;
+
+   if(topWdInfo == NULL){
+      return;
+   }
+
+   p = topWdInfo;
+   do{
+      WD_INFO* del;
+      del = p;
+      p = p->next;
+      free(del->path);
+      inotify_rm_watch(fd, del->wd);
+      free(del);
+   }while(p != topWdInfo);
+   topWdInfo = NULL;
+}
+
+static void deleteWdInfo(int wd)
+{
+   WD_INFO* p;
+
+   if(topWdInfo == NULL){
+      return;
+   }
+
+   p = topWdInfo;
+   do{
+      if(p->wd == wd){
+         if(p->next == p->prev){
+            topWdInfo = NULL;
+         }else{
+            if(p == topWdInfo){
+               topWdInfo = p->next;
+            }
+            p->next->prev = p->prev;
+            p->prev->next = p->next;
+         }
+         free(p->path);
+         free(p);
+
+         return;
+      }
+      p = p->next;
+   }while(p != topWdInfo);
+
+   return;
+}
+
+/** @miura added */
+void print_datetime()
+{
+   time_t t = time(NULL);
+   struct tm *lcl = localtime(&t);
+   printf("%02d/%02d %02d:%02d:%02d ", lcl->tm_mon+1, lcl->tm_mday,
+         lcl->tm_hour, lcl->tm_min, lcl->tm_sec);
+}
+
+char cmd[255] = {};
+char prefix[63] = {};
+
+/** return true when target ends with find_prefix */
+int ends_with(char* target, char* find_prefix){
+   char *p = target;
+   char *q = find_prefix;
+   while( *p ) p++;
+   while( *q ) q++;
+   while( find_prefix <= q){
+      if (*p-- != *q--) return 0;
+   }
+   return 1;
+}
+void exec_cmd(char* target)
+{
+   pid_t pid;
+//   printf("target: %s\n", target);
+   if (strlen(prefix) == 0 || ends_with(target, prefix)){
+      if ((pid = fork()) == 0){
+         char *argv[] = { cmd, NULL };
+         execvp( cmd, argv );
+      } else {
+         wait(0);
+      }
+   }
+}
+
+int main(int argc, char** argv)
+{
+   struct timeval waitval;
+   int fd;
+   int ret;
+   fd_set readfds;
+
+   if (argc < 2){
+      printf("Usage: exec_on_modify command [prefix]\n");
+      printf("  command is executed when a file ends with [prefix] modified.\n");
+      printf("  example1:  exec_on_modify make .c \n");
+      printf("  example2:  exec_on_modify platex .tex \n");
+      exit(0);
+   }
+//   printf("%d\n", argc);
+   if (argc >= 2){
+      strcpy(cmd, argv[1]);
+   }
+   if (argc == 3){
+      strcpy(prefix, argv[2]);
+   }
+   printf("%s\n", cmd);
+   printf("%s\n", prefix);
+
+   fd = inotify_init();
+
+   getWdInfo(fd, (char*)WATCH_DIR);
+
+   while(1){
+      FD_ZERO(&readfds);
+      FD_SET(fd, &readfds);
+      ret = select(fd+1, &readfds, NULL, NULL, NULL);
+      if(0 < ret){
+         if(FD_ISSET(fd, &readfds)){
+            char* buf;
+            int len;
+            struct inotify_event* event;
+
+            buf = (char*)malloc(INOTIFY_EVENT_MAX);
+
+            //INOTIFY_EVENT_MAXを指定し、最低でも一つのイベントは読み込む。
+            len = read(fd, buf, INOTIFY_EVENT_MAX);
+
+            event = (struct inotify_event*)buf;
+
+            //複数イベントがあるかもしれない。全部処理するまでループ。
+            while(len > 0){
+               char* target;
+               if(event->len){
+                  target = event->name;
+               }else{
+                  target = wd2path(event->wd);
+               }
+
+               if(event->mask & IN_CLOSE_WRITE){
+                  if (target[0] !='.'){ 
+                     print_datetime();
+                     printf("Writtable [%s] was closed.\n", target);
+                     exec_cmd(target);
+                  }
+               }
+
+               if(event->mask & IN_CREATE && event->name[0]!='.' ){
+                  print_datetime();
+                  printf("[%s] was created in [%s].\n", event->name, wd2path(event->wd));
+                  char* dirname;
+                  int dirname_len;
+                  int eventname_len;
+                  char* fullpath;
+                  struct stat st;
+
+                  dirname = wd2path(event->wd);
+                  eventname_len = strlen(event->name);
+                  fullpath = (char*)malloc(dirname_len + 1 + eventname_len + 1);
+                  strcpy(fullpath, dirname);
+                  strcat(fullpath, "/");
+                  strcat(fullpath, event->name);
+                  stat(fullpath, &st);
+
+                  if(S_ISDIR(st.st_mode)){
+                     //監視対象追加
+                     getWdInfo(fd, fullpath);
+                  }
+
+               }
+
+               if(event->mask & IN_IGNORED){
+                  // printf("[%s] was ignored.\n", target);
+                  //監視対象削除
+                  deleteWdInfo(event->wd);
+               }
+
+               len -= (sizeof(struct inotify_event) + event->len);
+               event = (struct inotify_event*)(((char*)event)+sizeof(struct inotify_event) + event->len);
+            }
+            free(buf);
+         }
+      }
+   }
+
+   closeAllWdInfo(fd);
+   close(fd);
+
+   return 0;
+}
+
diff --git a/inotify/show_events.c b/inotify/show_events.c
new file mode 100644
index 0000000..16ea210
--- /dev/null
+++ b/inotify/show_events.c
@@ -0,0 +1,288 @@
+/**
+ * Original:
+ * https://blpr.net/?p=210
+ *
+ * 20201130 @miura added #include<unistd.h> to prevent warning of implicit declaration of functions:
+ * read / close.
+*/
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <sys/inotify.h>
+#include <sys/select.h>
+#include <limits.h>
+// @miura added
+#include <unistd.h>
+#include <time.h>
+ 
+#define WATCH_DIR "."
+ 
+//イベントサイズは16バイト境界
+#define INOTIFY_EVENT_MAX (((sizeof(struct inotify_event)+NAME_MAX+1)+16)&~16)
+ 
+typedef struct _WD_INFO
+{
+  struct _WD_INFO* prev;
+  struct _WD_INFO* next;
+  int wd;
+  char* path;
+} WD_INFO;
+ 
+static WD_INFO* topWdInfo = NULL;
+ 
+static void getWdInfo(int fd, char* dirname)
+{
+  DIR* dir = NULL;
+  struct dirent* entry;
+  struct stat st;
+  int wd;
+  int dirname_len;
+  int entname_len;
+  char* fullpath = NULL;
+  WD_INFO* newWdInfo;
+ 
+  newWdInfo = (WD_INFO*)malloc(sizeof(WD_INFO));
+ 
+  if(topWdInfo == NULL){
+    // first
+    topWdInfo = newWdInfo;
+    topWdInfo->prev = topWdInfo;
+    topWdInfo->next = topWdInfo;
+  }else{
+    newWdInfo->prev = topWdInfo->prev;
+    topWdInfo->prev->next = newWdInfo;
+    topWdInfo->prev = newWdInfo;
+    newWdInfo->next = topWdInfo;
+  }
+ 
+  newWdInfo->wd = inotify_add_watch(fd, dirname, IN_ALL_EVENTS);
+  newWdInfo->path = strdup(dirname);
+ 
+  //Search Sub directry
+  dir = opendir(dirname);
+ 
+  dirname_len = strlen(dirname);
+ 
+  while((entry = readdir(dir)) != NULL){
+ 
+    if(strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0){
+      continue;
+    }
+ 
+    //エントリのタイプ種別を非標準のd_typeを使わず、statで取得
+    entname_len = strlen(entry->d_name);
+    fullpath = (char*)malloc(dirname_len + 1 + entname_len + 1);
+    strcpy(fullpath, dirname);
+    strcat(fullpath, "/");
+    strcat(fullpath, entry->d_name);
+    stat(fullpath, &st);
+ 
+    if(S_ISDIR(st.st_mode)){
+      //再帰呼び出し
+      getWdInfo(fd, fullpath);
+    }
+ 
+    free(fullpath);
+  }
+ 
+  closedir(dir);
+}
+
+
+static char* wd2path(int wd)
+{
+  WD_INFO* p;
+ 
+  if(topWdInfo == NULL){
+    return NULL;
+  }
+ 
+  p = topWdInfo;
+  do{
+    if(p->wd == wd){
+      return p->path;
+    }
+    p = p->next;
+  }while(p != topWdInfo);
+ 
+  return NULL;
+}
+ 
+static void closeAllWdInfo(int fd)
+{
+  WD_INFO* p;
+ 
+  if(topWdInfo == NULL){
+    return;
+  }
+ 
+  p = topWdInfo;
+  do{
+    WD_INFO* del;
+    del = p;
+    p = p->next;
+    free(del->path);
+    inotify_rm_watch(fd, del->wd);
+    free(del);
+  }while(p != topWdInfo);
+  topWdInfo = NULL;
+}
+ 
+static void deleteWdInfo(int wd)
+{
+  WD_INFO* p;
+ 
+  if(topWdInfo == NULL){
+    return;
+  }
+ 
+  p = topWdInfo;
+  do{
+    if(p->wd == wd){
+      if(p->next == p->prev){
+        topWdInfo = NULL;
+      }else{
+        if(p == topWdInfo){
+          topWdInfo = p->next;
+        }
+        p->next->prev = p->prev;
+        p->prev->next = p->next;
+      }
+      free(p->path);
+      free(p);
+ 
+      return;
+    }
+    p = p->next;
+  }while(p != topWdInfo);
+ 
+  return;
+}
+
+/** @miura added */
+void print_datetime()
+{
+	time_t t = time(NULL);
+	struct tm *lcl = localtime(&t);
+	printf("%02d/%02d %02d:%02d:%02d ", lcl->tm_mon+1, lcl->tm_mday,
+			lcl->tm_hour, lcl->tm_min, lcl->tm_sec);
+}
+
+int main(int argc, char** argv)
+{
+  struct timeval waitval;
+  int fd;
+  int ret;
+  fd_set readfds;
+
+  fd = inotify_init();
+
+  getWdInfo(fd, (char*)WATCH_DIR);
+
+  while(1){
+    FD_ZERO(&readfds);
+    FD_SET(fd, &readfds);
+    ret = select(fd+1, &readfds, NULL, NULL, NULL);
+    if(0 < ret){
+      if(FD_ISSET(fd, &readfds)){
+        char* buf;
+        int len;
+        struct inotify_event* event;
+
+        buf = (char*)malloc(INOTIFY_EVENT_MAX);
+
+        //INOTIFY_EVENT_MAXを指定し、最低でも一つのイベントは読み込む。
+        len = read(fd, buf, INOTIFY_EVENT_MAX);
+
+        event = (struct inotify_event*)buf;
+
+        //複数イベントがあるかもしれない。全部処理するまでループ。
+        while(len > 0){
+          char* target;
+          if(event->len){
+            target = event->name;
+          }else{
+            target = wd2path(event->wd);
+          }
+
+	  print_datetime();
+
+
+          if(event->mask & IN_ACCESS){
+            printf("[%s] was accessed.\n", target);
+          }
+          if(event->mask & IN_MODIFY){
+            printf("[%s] was modified.\n", target);
+          }
+          if(event->mask & IN_ATTRIB){
+            printf("Metadata of [%s] changed.\n", target);
+          }
+          if(event->mask & IN_CLOSE_WRITE){
+            printf("Writtable [%s] was closed.\n", target);
+          }
+          if(event->mask & IN_CLOSE_NOWRITE){
+            printf("Unwrittable [%s] closed.\n", target);
+          }
+          if(event->mask & IN_OPEN){
+            printf("[%s] was opened.\n", target);
+          }
+          if(event->mask & IN_MOVED_FROM){
+            printf("[%s] was moved from X.\n", target);
+          }
+          if(event->mask & IN_MOVED_TO){
+            printf("[%s] was moved to Y.\n", target);
+          }
+          if(event->mask & IN_CREATE){
+            printf("[%s] was created in [%s].\n", event->name, wd2path(event->wd));
+            char* dirname;
+            int dirname_len;
+            int eventname_len;
+            char* fullpath;
+            struct stat st;
+
+            dirname = wd2path(event->wd);
+            eventname_len = strlen(event->name);
+            fullpath = (char*)malloc(dirname_len + 1 + eventname_len + 1);
+            strcpy(fullpath, dirname);
+            strcat(fullpath, "/");
+            strcat(fullpath, event->name);
+            stat(fullpath, &st);
+
+            if(S_ISDIR(st.st_mode)){
+              //監視対象追加
+              getWdInfo(fd, fullpath);
+            }
+
+	              }
+          if(event->mask & IN_DELETE){
+            printf("[%s] was deleted in [%s].\n", event->name, wd2path(event->wd));
+          }
+          if(event->mask & IN_DELETE_SELF){
+            printf("[%s] was deleted.\n", target);
+          }
+          if(event->mask & IN_MOVE_SELF){
+            printf("[%s] was moved.\n", target);
+          }
+
+          if(event->mask & IN_IGNORED){
+            printf("[%s] was ignored.\n", target);
+            //監視対象削除
+            deleteWdInfo(event->wd);
+          }
+
+          len -= (sizeof(struct inotify_event) + event->len);
+          event = (struct inotify_event*)(((char*)event)+sizeof(struct inotify_event) + event->len);
+        }
+        free(buf);
+      }
+    }
+  }
+
+  closeAllWdInfo(fd);
+  close(fd);
+
+  return 0;
+}
+