General tips

• Uppercase and lowercase letters are different:
  • A file called thesis.txt is different from Thesis.txt and tHeSiS.tXt
• Highlight text in the terminal and right click to paste text
  • Right clicking also works for pasting from the Windows clipboard
• Press the up arrow on your keyboard to cycle through previous commands
• Tab will autocomplete file/directory names when typing commands
• Be careful with spaces when writing commands - spaces should separate each option or argument

Basic navigation

ls	list contents of the current directory (except hidden files)
ls -a	list all contents of the current directory
ls -l	long-form list of contents, showing file properties
ls <path>	list contents of specified directory
pwd	print working directory (full path)
cd <path>	go to specified directory
cd ..	go up one level to parent directory
cd ~	go to current user's home directory

Files and directories

mkdir <new-directory>	create a new directory
mkdir -p abc/123	create two directories: one called 123 inside another called abc
cp <file-name> <new-file-name>	create a copy of a file with a new name
cp <file-name> <path>	copy a file to another folder
cp <file-name> <path>/<new-file-name>	create a copy with a new name in another folder
mv <file-name> <new-file-name>	rename a file
mv <file-name> <path>	move a file to another folder
rm <file-name>	delete a file
rm -r <directory>	delete a directory and all of its contents
nano <file-name>	open a new or existing file in a simple text editor
chmod ug+x <file-name>	give user and group execute permission for a file

Inspecting file contents

cat <file-name>	print the contents of a file to the screen
less <file-name>	opens file contents for inspection, allows scrolling, type q to quit
head -5 <file-name>	prints first 5 lines of a file
tail -3 <file-name>	prints last 3 lines of a file
sdiff <file-name> <file-name>	visualise and compare two files side by side

Wildcards

ls *.txt	list all files ending in .txt
ls ???	list all files with names exactly three characters long
ls [abc]*	list all files beginning with a, b or c

Output redirection and pipiing

echo "Some text" > a-file	send standard output of a command to a file (overwrites existing content)
echo "Some text" >> a-file	append standard output of a command to the end of a file (no overwrite)
ls | sort	pipe standard output of a command to another command

Variables, sequences and loops

VAR1=hello	create a variable and set its value
echo \$VAR1	print the value of VAR1
FILENAMES=\$(ls)	save the output of a command as a variable
SUM=\$((2 + \$TWO))	perform integer arithmetic with variables
seq 5 10	print a sequence from 5 to 10
seq 1 2 9	print a sequence from 1 to 9 with a stride of 2
seq -f %03g 1 2 9	print a sequence padded with zeroes to the left
for i in \$(seq 1 5); do echo iteration$i; done	loop through a sequence and repeat the same instruction for each value
for ((i=1; i<=5; i++)); do echo iteration$i; done	alternative method for looping through a sequence