> For the complete documentation index, see [llms.txt](https://42-guide.gitbook.io/42-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://42-guide.gitbook.io/42-guide/piscine-life/shell00/midls.md).

# midLS

**Objective:**

The goal of this exercise is to create a command that lists all files and directories in the current directory (excluding hidden files and directories) in a specific format. The output should be sorted by modification date, and directory names should be followed by a slash (`/`).

**Instructions:**

1. **Create a File Named `midLS`:**
   * In the `ex04/` directory, create a file named `midLS`.
   * This file should contain a command or script that lists all files and directories in the current directory, excluding hidden files (those starting with a dot `.`), and separates them by a comma and a space.
2. **Format the Output:**
   * The output should list files and directories in order of their modification date (oldest first).
   * Directory names should be followed by a slash (`/`).
   * The output should not include hidden files or directories (those starting with a dot `.`).
3. **Example Output:**
   * If your directory contains the following files and directories:

     ```
     file1.txt
     dir1/
     file2.txt
     dir2/
     ```
   * The output of your `midLS` command should look like this:

     ```
     file1.txt, dir1/, file2.txt, dir2/
     ```

**Detailed Steps:**

1. **Create the `midLS` File:**
   * Open your terminal and navigate to the `ex04/` directory.
   * Create a file named `midLS`:

     ```bash
     touch midLS
     ```
2. **Write the Command:**
   * Open the `midLS` file in a text editor and add the following command:

     ```bash
     ls -ptm
     ```
   * This command does the following:
     * Lists all files and directories in the current directory, excluding hidden files.
     * Sorts them by modification date.
     * Appends a slash (`/`) to directory names.
     * Separates the output with a comma and a space.
3. **Make the File Executable:**
   * After saving the file, make it executable by running:

     ```
     chmod +x midLS
     ```
4. **Test the Command:**
   * Run the `midLS` command to see if it produces the expected output:

     bashCopy

     ```
     ./midLS
     ```

**What You Will Learn:**

* **File Listing:** You will learn how to list files and directories in a specific format using the `ls` command.
* **Sorting by Date:** You will understand how to sort files and directories by their modification date.
* **Excluding Hidden Files:** You will learn how to exclude hidden files (those starting with a dot `.`) from the output.
* **Formatting Output:** You will gain experience in formatting command output using tools like `awk`, `xargs`, and `sed`.

**Useful Resources:**

* [**Linux LS Command**](https://linux.die.net/man/1/ls)**:** Official documentation for the `ls` command.
* [**AWK Command**](https://www.gnu.org/software/gawk/manual/gawk.html)**:** A guide to using `awk` for text processing.
* [**SED Command**](https://www.gnu.org/software/sed/manual/sed.html)**:** Documentation for the `sed` stream editor.
* [**Xargs Command**](https://linux.die.net/man/1/xargs)**:** A guide to using `xargs` for building and executing command lines.

**Conclusion:**

This exercise helps you understand how to manipulate and format file listings in a Unix-like environment. By completing this exercise, you will gain practical experience in using command-line tools to filter, sort, and format output, which are essential skills for any developer working in a terminal environment.


---

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