Class PPT

Shell Script

Demos

Initial Setup

Assume the directory contains three text files: file1.txt, file2.txt, file3.txt.

1. Command: ls

   file1.txt  file2.txt  file3.txt
   

2. Command: rename "s/.txt/.cpp/" *.txt

   • Renames all .txt files to .cpp.
   • New files: file1.cpp, file2.cpp, file3.cpp.

   file1.cpp  file2.cpp  file3.cpp
   

3. Command: ls

   file1.cpp  file2.cpp  file3.cpp
   

4. Command: mkdir demo

   • Creates a directory named demo.

5. Command: cd demo/

   • Changes to the demo directory.

6. Command: ls

   • The demo directory is empty.

   (empty)
   

7. Command: cat > target.txt

   • Assume user inputs some text (e.g., "Hello, this is target.txt") and saves the file.
   • Creates target.txt with content: Hello, this is target.txt.

8. Command: cat target.txt

   Hello, this is target.txt
   

9. Command: ls -l -i

   • Lists files with inode numbers. Assume target.txt has inode 1001.

   1001 -rw-r--r-- 1 user user 24 Apr 14 14:00 target.txt
   

10. Command: ln target.txt link.txt

    • Creates a hard link link.txt to target.txt. Both share inode 1001.