Linux Commands for Beginners: A cheatsheet: PART 1

Author: Muhammad Faizan Khan (Hackbio '24)

Section 1: Essential Linux Symbols in Command-Line Operations?

1. Tilde (~): Used to represent the home directory of the current user.
2. Asterisk (*): Acts as a wildcard character that matches any character (of any length) in filenames or commands. For example: ls *.txt lists all file ending with .txt
3. Question Mark (?): Represents a single character in a filename or command. For example ls file?.txt will list files like file1.txt, file2.txt, but not file01.txt.??
4. Pipe (|): Sends the output of one command as input to another command.?For example grep "gene" file.txt | wc -l counts the number of lines containing "gene"
5. Semicolon (;): ?Allows you to execute multiple commands in succession, regardless of their execution status.?For example: cd /var; ls changes the directory to /var and then lists its contents.?
6. Ampersand (&): Runs a command in the background?
7. Greater Than (>): Redirects the output of a command to a file, overwriting the existing content. For example: echo "Hello World" > file.txt writes "Hello World" to file.txt
8. Double Greater Than (>>): Appends the output of a command to a file. For example: echo "Hello again" >> file.txt appends "Hello again" to file.txt??
9. Less Than (<): Takes input from a file instead of the keyboard. For example, grep "search" < file.txt searches for "search" in file.txt.

?In the next part, we will discuss the essential commands.

For a practical guided/mentored tour on the use of these commands in solving important problems in bioinformatics, healthcare and data analysis, visit our course page (https://thehackbio.com/courses/25).