Current path (pwd)

pwd

Print Working Directory: displays the absolute path of the current directory.

List files (ls)

ls

Lists visible files and folders in the current directory.

Show hidden files (ls -a)

ls -a

Includes hidden files (those starting with a dot, e.g., .bashrc).

Detailed listing (ls -l)

ls -l

Shows permissions, owner, file size, and last modified date.

Enter a folder

cd documents
cd /var/log

Accepts relative paths (documents) or absolute paths (starting with /).

Go back (cd ..)

cd ..

Moves the terminal up one directory level to the parent folder.

Home folder (cd ~)

cd ~

Moves to the home directory of the current user (e.g., /home/user).

Previous folder (cd -)

cd -

Returns to the last directory visited before the current one.

Create an empty file (touch)

touch app.log
touch index.html

If the file already exists, updates its modification timestamp without modifying its contents.

Create a directory (mkdir)

mkdir projects

Create nested paths (mkdir -p)

mkdir -p projects/frontend/src

The -p option creates any missing parent directories recursively.

Copy a file (cp)

cp info.txt backup.txt

Copy a directory (cp -r)

cp -r documents backup_documents

The -r option indicates recursive copying, which is mandatory for directories.

Move or rename (mv)

mv info.txt docs/info.txt
mv old.txt new.txt

If the destination is a directory, moves the file; otherwise, renames it.

Delete files (rm)

rm file.txt

Warning: command line deletion is immediate and permanent (does not go to trash).

Delete directories (rm -r)

rm -r projects_folder

Recursive deletion, required to remove directories and all their contents.

Force delete (rm -f)

rm -f protected_file.txt
rm -rf folder_to_delete

The -f option ignores non-existent files and never prompts for confirmation.

Print messages (echo)

echo "Welcome to the terminal"

Read file content (cat)

cat notes.txt

Concatenates and prints: prints the entire contents of one or more files.

Redirect and overwrite (>)

echo "New text" > file.txt

Redirects the output of a command into a file, overwriting its existing content.

Redirect and append (>>)

echo "Additional note" >> file.txt

Appends output to the end of the file, without erasing pre-existing text.

Chain commands (|)

cat log.txt | grep "ERROR"

The pipe (|) feeds the standard output of the first command as standard input to the second.

Search within a file (grep)

grep "warning" sys.log

Filters and prints only the lines containing the specified text pattern.

Case-insensitive search (grep -i)

grep -i "error" sys.log

Searches while ignoring case differences (e.g., matches Error, ERROR, error).

Recursive folder search (grep -r)

grep -r "TODO" src/

Searches for the text pattern inside all files in the target directory and its subdirectories.