LWM-Linux/02 - Basic System Operations/File and Directory Management.md

# Linux File and Directory management

## 1. File System Hierarchy:
Linux follows a hierarchical file system structure, starting with the root directory (/). Key directories include:

- /home: User home directories
- /etc: System configuration files
- /var: Variable data (logs, temporary files)
- /usr: User binaries and program files
- /bin: Essential command binaries
- /sbin: System binaries
- /tmp: Temporary files

## 2. Basic Commands:

### - Listing files and directories:
```
ls [options] [directory]
```
Common options:
- -l: Long format
- -a: Show hidden files
- -h: Human-readable file sizes

### - Changing directories:
```
cd [directory]
```
- cd ..: Move up one directory
- cd ~: Go to home directory
- cd /: Go to root directory

### - Creating directories:
```
mkdir [options] directory_name
```
Common options:
- mkdir -p: Create parent directories if they don't exist

### - Removing directories:
```
rmdir [options] directory_name
```
Common options:
- rm -r directory_name: Remove non-empty directories

### - Creating files:
```
touch file_name
```

### - Copying files and directories:
```
cp [options] source destination
```
Common options:
- cp -r: Copy directories recursively

### - Moving/renaming files and directories:
```
mv source destination
```

### - Removing files:
```
rm [options] file_name
```
Common options:
- rm -f: Force removal without prompting

## 3. File Permissions:

Linux uses a permission system with read (r), write (w), and execute (x) permissions for owner, group, and others.

### Viewing permissions:
```
ls -l
```

### Changing permissions:
```
chmod [options] mode file
```
Example: chmod 755 file_name

### Changing ownership:
```
chown [options] user:group file
```

## 4. File Manipulation:

### Viewing file contents:
```
cat file_name #Print entire file at once
less file_name #View file in a pager format
more file_name #View file in a pager format
head file_name #View top 10 lines (default) of a file
tail file_name #View last 10 lines (default) of a file
```

### Searching file contents:
```
grep [options] pattern file
```
Common options:
- -i: Insensitive Case Search
- -R: search recursively in parent Directory, as well as all child directories.

### Comparing files:
```
diff file1 file2
```

## 5. Advanced File Management:

### Finding files:
```
find [path] [expression]
```
Example: find /home -name "*.txt"

### Disk usage:
```
du [options] [directory]
```
Common options:
- -h: Print disk usage in human-readable format
- -s: Summarize disk usage information

### File compression and archiving:
```
tar [options] archive_name files
gzip file_name
gunzip file_name.gz
```

### Symbolic links:
```
ln -s target_file link_name
```

## 6. Text Editors:

- nano: Simple and user-friendly
- vim: Advanced and powerful
- emacs: Extensible and feature-rich

## 7. File System Management:

### Mounting file systems:
```
mount [options] device directory
```

### Unmounting file systems:
```
umount [options] directory
```

### Checking disk space:
```
df [options]
```
- df -h: Human-readable output

## 8. File System Maintenance:

### Checking and repairing file systems:
```
fsck [options] device
```

### Creating file systems:
```
mkfs [options] device
```

## 9. Access Control Lists (ACLs):

### For more fine-grained permission control:
```
getfacl file
setfacl -m u:user:rwx file
```

## 10. Inode Information:

### View detailed file information:
```
stat file_name
```

- [(1) How to Perform File and Directory Management (Part 3) - Tecmint.](https://www.tecmint.com/file-and-directory-management-in-linux/.)
- [(2) How to Manage Files from the Linux Terminal: 11 Commands ... - How-To Geek.](https://www.howtogeek.com/107808/how-to-manage-files-from-the-linux-terminal-11-commands-you-need-to-know/.)
- [(3) Linux File Management Series for Beginners - Linux Shell Tips.](https://www.ubuntumint.com/linux-file-management/.)
- [(4) Linux Commands Cheat Sheet {with Free Downloadable PDF} - phoenixNAP.](https://phoenixnap.com/kb/linux-commands-cheat-sheet.)