diff --git a/week10/_ex1.txt b/week10/_ex1.txt
new file mode 100644
index 0000000..72867bc
--- /dev/null
+++ b/week10/_ex1.txt
@@ -0,0 +1 @@
+RinRi
diff --git a/week10/_ex1_1.txt b/week10/_ex1_1.txt
new file mode 100644
index 0000000..72867bc
--- /dev/null
+++ b/week10/_ex1_1.txt
@@ -0,0 +1 @@
+RinRi
diff --git a/week10/_ex1_2.txt b/week10/_ex1_2.txt
new file mode 100644
index 0000000..72867bc
--- /dev/null
+++ b/week10/_ex1_2.txt
@@ -0,0 +1 @@
+RinRi
diff --git a/week10/_ex3.txt b/week10/_ex3.txt
new file mode 100755
index 0000000..039727e
--- /dev/null
+++ b/week10/_ex3.txt
@@ -0,0 +1 @@
+lol
diff --git a/week10/ex1.sh b/week10/ex1.sh
new file mode 100755
index 0000000..1ab7087
--- /dev/null
+++ b/week10/ex1.sh
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+rm -f _ex1*
+echo "RinRi" > _ex1.txt
+ln -f _ex1.txt _ex1_1.txt
+ln -f _ex1.txt _ex1_2.txt
+ls -i _ex1.txt > ex1.txt
+ls -i _ex1_1.txt >> ex1.txt
+ls -i _ex1_2.txt >> ex1.txt
diff --git a/week10/ex1.txt b/week10/ex1.txt
new file mode 100644
index 0000000..063fde8
--- /dev/null
+++ b/week10/ex1.txt
@@ -0,0 +1,3 @@
+6817598 _ex1.txt
+6817598 _ex1_1.txt
+6817598 _ex1_2.txt
diff --git a/week10/ex2.sh b/week10/ex2.sh
new file mode 100755
index 0000000..ede974a
--- /dev/null
+++ b/week10/ex2.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+
+rm -f ../week01/file.txt _ex2.txt
+echo "file" > ../week01/file.txt
+ln -f ../week01/file.txt _ex2.txt
+inode=$(find _ex2.txt -printf '%i')
+find .. -inum "$inode" > ex2.txt
+find .. -inum "$inode" -exec rm {} \; >> ex2.txt
diff --git a/week10/ex2.txt b/week10/ex2.txt
new file mode 100644
index 0000000..62b56a6
--- /dev/null
+++ b/week10/ex2.txt
@@ -0,0 +1,2 @@
+../week10/_ex2.txt
+../week01/file.txt
diff --git a/week10/ex3.sh b/week10/ex3.sh
new file mode 100755
index 0000000..6eefe1e
--- /dev/null
+++ b/week10/ex3.sh
@@ -0,0 +1,13 @@
+#!/bin/sh
+
+rm -f _ex3.txt
+echo "lol" > _ex3.txt
+chmod a-x _ex3.txt
+ls -l _ex3.txt > ex3.txt
+chmod 707 _ex3.txt
+ls -l _ex3.txt >> ex3.txt
+chmod a=u _ex3.txt
+ls -l _ex3.txt >> ex3.txt
+echo "660 means read and write permissions (6) for user and the group" >> ex3.txt
+echo "775 means read, write, and execute permissions (7) for user and the group, and read and execute permissions (5) for others" >> ex3.txt
+echo "777 means read, write, and execute permissions (7) for everyone" >> ex3.txt
diff --git a/week10/ex3.txt b/week10/ex3.txt
new file mode 100644
index 0000000..f3b5c03
--- /dev/null
+++ b/week10/ex3.txt
@@ -0,0 +1,6 @@
+-rw-r--r-- 1 rinri users 4 Nov 15 21:08 _ex3.txt
+-rwx---rwx 1 rinri users 4 Nov 15 21:08 _ex3.txt
+-rwxrwxrwx 1 rinri users 4 Nov 15 21:08 _ex3.txt
+660 means read and write permissions (6) for user and the group
+775 means read, write, and execute permissions (7) for user and the group, and read and execute permissions (5) for others
+777 means read, write, and execute permissions (7) for everyone
diff --git a/week10/ex4.c b/week10/ex4.c
new file mode 100644
index 0000000..54ddf02
--- /dev/null
+++ b/week10/ex4.c
@@ -0,0 +1,71 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <sys/stat.h>
+
+struct file {
+    ino_t inode;
+    char names[64][256];
+    int sz;
+};
+
+int putToFiles(char name[256], ino_t inode, struct file *files, int sz) {
+    // if found the same inode
+    for (int i = 0; i < sz; ++i) {
+        if (files[i].inode == inode) {
+            memcpy(files[i].names[files[i].sz++], name, 256);
+            return sz;
+        }
+    }
+
+    // if not found
+    files[sz].inode = inode;
+    memcpy(files[sz].names[0], name, 256);
+    files[sz].sz = 1;
+    sz++;
+
+    return sz;
+}
+
+int main() {
+    DIR *d = opendir("./tmp");
+    if (d == NULL) {
+        perror("opendir");
+        exit(1);
+    }
+
+    struct file files[64];
+    int sz = 0;
+
+    struct dirent *entry;
+    while ((entry = readdir(d))!= NULL) {
+        if (entry->d_name[0] == '.')
+            continue;
+
+        //printf("%s ", entry->d_name);
+        struct stat s;
+        char buf[256] = "./tmp/";
+        strncpy(buf + strlen(buf), entry->d_name, 200);
+
+        if (stat(buf, &s) == -1) {
+            perror("stat");
+            exit(1);
+        }
+
+        sz = putToFiles(entry->d_name, s.st_ino, files, sz);
+    }
+
+    printf("File --- Hard links\n");
+    for (int i = 0; i < sz; ++i) {
+        if (files[i].sz > 1) {
+            for (int j = 0; j < files[i].sz; ++j) {
+                printf("%s --- ", files[i].names[j]);
+                for (int k = 0; k < files[i].sz; ++k) {
+                    printf("%s ", files[i].names[k]);
+                }
+                printf("\n");
+            }
+        }
+    }
+}
diff --git a/week10/ex4.out b/week10/ex4.out
new file mode 100755
index 0000000..ce4b8fc
Binary files /dev/null and b/week10/ex4.out differ
diff --git a/week10/ex4.sh b/week10/ex4.sh
new file mode 100755
index 0000000..5ec3c6e
--- /dev/null
+++ b/week10/ex4.sh
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+rm -rf tmp
+mkdir tmp
+touch tmp/file1 tmp/file2
+ln tmp/file1 tmp/link1
+
+gcc ex4.c -o ex4.out
+./ex4.out
diff --git a/week10/tmp/file1 b/week10/tmp/file1
new file mode 100644
index 0000000..e69de29
diff --git a/week10/tmp/file2 b/week10/tmp/file2
new file mode 100644
index 0000000..e69de29
diff --git a/week10/tmp/link1 b/week10/tmp/link1
new file mode 100644
index 0000000..e69de29