linux commands

Below is a list of Linux Commands and examples of their use, for more information see the man page of each command:

cat

concatenates files and write contents of file to terminal 

Ex:

$ cat some_file_here

cd

change directory

Ex:

$ cd /some/directory/here

chgrp

change group of a file

Ex:

$ chgrp <new group> /some/file/here

chmod

change mode (permissions) of a file

Ex:

$ chmod <mode/permissions> /some/file/here

$ chmod 0721 my_file.c

$ chmod u+rwx my_file.c

$ chmod g-rx my_file.c

chown

change owner of a file

Ex:

$ chown <new owner> /some/file/here

echo

writes a string to the terminal

Ex:

$ echo <some text here>

grep

searches a file for a given string, and lists results

Ex:

$  grep <some string here> <some file here>

ln

links a file to another file

Ex:

$ ln /some/file/here /some/alias/here

$ ln -s /some/file/here /some/symbolic/link/name/here

ls

list directory contents

Ex:

$ ls /some/directory/here

mkdir

makes a directory

Ex:

$ mkdir /some/new/directory/here

mkfifo

creates a named pipe

Ex:

$ mkfifo /some/new/named/pipe/here

pwd

prints the working directory

Ex:

$ pwd

rm

remove file

Ex:

$ rm some_file_here

rmdir

removes a directory

Ex:

$ rmdir /some/directory/here

tee

reads from the standard input and writes to standard output or files

Ex:

$ echo hello | tee /some/file/here

touch

create file or changes the timestamp

Ex:

$ touch some_file_here

wc

word count (counts the number of lines, words, and characters in a file)

Ex:

$ wc /some/file/here