Master Linux Command Line: Detailed Guide to ls, pwd, cd, and More

1. ls command

Syntax

ls [options] [directory|file]

Function

Lists the contents of a directory or displays information about a file.

Common options

-a – include hidden files (those starting with a dot).

-d – show directories themselves, not their contents.

-i – display the inode number.

-k – show file sizes in kilobytes.

-l – use a long listing format with detailed attributes.

-n – display numeric UID and GID instead of names.

-F – append a character to indicate file type (e.g., * for executables, / for directories).

-r – reverse the sort order.

-t – sort by modification time.

-s – show file size before the name.

-R – list sub‑directories recursively.

-1 – output one entry per line.

Example

ls -la

2. pwd command

Syntax

pwd

Function

Prints the absolute pathname of the current working directory.

Example

pwd

3. cd command

Syntax

cd directory_name

Function

Changes the current working directory to the specified path.

Example

cd ..            # go to parent directory
cd /root/Desktop/w   # absolute path
cd Desktop           # relative path
cd ~                 # home directory
cd -                 # previous directory

4. mkdir command

Syntax

mkdir [options] dirname...

Function

Creates one or more new directories.

Common options

-p, --parents – create parent directories as needed.

Example

mkdir -p path/to/newdir

5. rmdir command

Syntax

rmdir [options] directory_name

Function

Removes empty directories; fails if the directory is not empty.

Common options

-p, --parents – remove parent directories as long as they become empty.

-v, --verbose – show detailed removal information.

Example

rmdir -p a/b/c

6. rm command

Syntax

rm [options] file_name

Function

Deletes files or directories (with appropriate options).

Common options

-f, --force – ignore nonexistent files and never prompt.

-i – prompt before each removal.

-I – prompt once before removing many files or recursively.

-r, -R – remove directories and their contents recursively.

-d – remove empty directories.

-v, --verbose – explain what is being done.

Example

rm -rfv a.txt

7. touch command

Syntax

touch [options] file_name

Function

Creates an empty file or updates the access and modification timestamps of existing files.

Common options

-a – change only the access time.

-c, --no-create – do not create a new file if it does not exist.

-d, --date – use a specified date/time instead of the current time.

-m – change only the modification time.

-r, --reference – use timestamps from another file.

-t – specify a timestamp in the format [[CC]YY]MMDDhhmm[.ss].

Example

touch newfile.txt

8. man command

Syntax

man [options] command

Function

Displays the manual page for a given command, providing detailed usage, options, and examples.

Common options

-f, --whatis – show a one‑line description.

-k, --apropos – search manual page names and descriptions.

-a, --all – display all matching manual pages.

-w, --where – show the location of the manual file.

-l, --local-file – show a local (non‑translated) manual page.

-P, --pager – specify the pager program.

Example

man ls

9. cp command

Syntax

cp [options] source_file target_file

Function

Copies files or directories.

Common options

-a, --archive – copy recursively and preserve attributes (equivalent to -dR --preserve=all).

-f, --force – overwrite without prompting.

-i, --interactive – prompt before overwriting.

-r, -R, --recursive – copy directories recursively.

-u, --update – copy only when the source is newer.

-v, --verbose – show progress.

-p, --preserve – preserve mode, ownership, timestamps.

--backup – make a backup of each existing destination file.

--parents – preserve the source file’s path hierarchy.

--sparse – control creation of sparse files.

Example

cp -v a.txt file2.txt

10. cat command

Syntax

cat [options] [file_name...]

Function

Concatenates and displays file contents, creates new files, or merges multiple files.

Common options

-A – show all characters, including non‑printable ones.

-b – number non‑empty output lines.

-e – display non‑printable characters and a $ at line ends.

-n – number all output lines.

-s – squeeze multiple blank lines into a single blank line.

-T – display TAB characters as ^I.

-v – show non‑printable characters except TAB and line ends.

Example

cat -n file2.txt

11. less command

Syntax

less [options] file_name

Function

Pages through a file, allowing forward and backward navigation, searching, and more advanced features than the basic more command.

Common options

-N – display line numbers.

-X – do not clear the screen on exit.

-F – automatically display the whole file if it fits on one screen.

-S – do not wrap long lines.

-i – ignore case in searches.

-g – highlight only the last search match.

Example

less -N file2.txt

12. find command

Syntax

find [options] [path...] [expression]

Function

Searches for files and directories in a directory hierarchy and can execute actions on matches.

Common options

-name – case‑sensitive name match.

-iname – case‑insensitive name match.

-type – filter by file type (f, d, l, etc.).

-size – filter by file size.

-mtime – filter by modification time.

-user – filter by file owner.

-group – filter by group.

-perm – filter by permissions.

-exec – run a command on each matched file.

-delete – delete matched files.

-print – display matched files (default).

Example

find /home -name "*.txt"

13. tar command

Syntax

tar [options] [file]

Function

Creates, extracts, and manipulates archive files.

Common options

-c – create a new archive.

-x – extract files from an archive.

-f – specify the archive file name.

-v – verbosely list processed files.

-t – list archive contents.

-z – filter the archive through gzip.

-j – filter the archive through bzip2.

-r – append files to an existing archive.

-u – only append newer files.

-C – change to a directory before performing operations.

Example

tar -cvf archive.tar a.c w.c

tar -xvf archive.tar

14. sz command

Syntax

sz [options] file_name

Function

Transfers files from a Linux server to a local machine using the ZMODEM protocol.

Common options

-a – ASCII (text) transfer.

-b – binary transfer.

-e – escape control characters.

-r – resume an interrupted transfer.

-v – verbose output.

-y – overwrite existing files on the receiver.

Example

sz -a file.txt

15. rz command

Syntax

rz [options]

Function

Receives files from a local machine to a Linux server using the ZMODEM protocol.

Common options

-y – overwrite existing files.

-e – escape control characters.

-v – verbose output.

-b – binary transfer.

-a – ASCII (text) transfer.

Example

rz -y

rz -b

rz -a