Working with File System

 Working With Files

Creating a File

touch

creates an empty file.

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touch filename

Viewing File Content

cat

reads contents of file and prints it.

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cat filename

Echo

echo

output/prints a string in the terminal.

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echo "content"

Writing to Files Using echo Command

Using > operator we can redirect the output of echo command to a file.

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echo "Hello World!" > filename

Renaming a File

• mv
   renames the file names.
• destination can be a new or existing file.

Syntax

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mv source destination

Example:

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mv practice.txt exam.txt

Copying Files

cp

copies src_file to dest_file.

Syntax

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cp src_file dest_file

Example:

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cp exam.txt fun_text.txt

Note :If dest_file already exist then 

cp

 overrides the contents of dest_file.

Deleting a File

rm

removes (delete) files.

Syntax

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rm filename

Example

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rm exam.txt

Hidden Files

• Linux, by default, hides many of the sensitive system files, in order to avoid accidental changes.

• Hidden files starts with "."

• ls -a
  shows the hidden files.

• ls -a
  also shows the current and parent directories:
  • . represents Current directory
  • .. represents parent directory

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ls -a

Summary

Command	Description
touch	Creates an empty file
cat	Reads contents of file and prints it
echo	Writes text to standard output
mv	Renames the file names
cp	Copies content from files
rm	Removes (delete) files
ls -a	Shows the hidden files

Working with Directories

Creating A Directory

mkdir

creates a directory.

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mkdir directory_path

Current Working Directory

pwd

prints name of current working directory.

Changing the Current Working Directory

cd

changes the current working directory.

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cd directory_path

Note :

cd /

 changes your current directory to root folder.

Creating a Directory in Directory

mkdir

creates a directory.

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mkdir directory_name

Switching to Parent Directory

• cd ..
  move to parent directory.

• Here .. is relative path to parent directory.

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cd ..

File Paths

There are two notations for file paths: 1. Absolute Path 2. Relative Path

Absolute Path:

Representing the complete path of a file or folder from the root.

Relative Path:

Representing the path of a file or folder wrt. current working directory.

In relative path conventions:

• . refers to the current working directory.

• .. refers to the parent directory.

Home Directory

Each user in the computer is given a separate directory to work with - called home directory.

• cd ~
   can be used to switch to home directory.

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cd ~

• cd
   (cd and space) command can also be used to switch to home directory.

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cd

Renaming a directory

mv

renames the directory name

Syntax

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mv source destination

Example

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mv tutorial commands

Moving a directory

mv

moves files or directories from source to destination paths.

Syntax

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mv source destination

Example

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mv welcome.txt commands

Copying Files to Another Directory

cp

can be used to copy files between directories.

Syntax

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cp file_path directory_name

Example

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cp welcome.txt commands

Copying Directory

cp -r

can be used to copy a directory.

Syntax

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cp -r source_path destination_path

Example

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cp -r commands linux

Common Mistake

Raises an error if destination path have any non existing directories in between.

Deleting a Directory

rm -r

removes(deletes) directories.

Syntax

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rm -r directory_name

Example:

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rm -r commands

Summary

We can use folder/file paths for cp, mv, rm commands.

Command	Description
mkdir	Creates a directory
pwd	Prints name of current working directory
cd	Changes the current working directory
rm -r	Deletes a directory