Xing's Blog

head - output the first part of files

less - to browse a file one page at a time

nl - number lines of files.

cat - print and concatenate files.

touch - change file timestamps, or create a file if the file does not exist.

rm - remove files or directories.

cp - copy files and folders.

mv - Move or rename files and directories.

rmdir - Removes a directory.

mkdir - Creates a directory. Current user must have write permission in the current directory in order to create a new directory.

grep command, which stands for “global regular expression print,” processes text line by line
and prints any lines which match a specified pattern.

To print only the matched part, use -o option

pwd - Print full name of current/working directory.

cd - Change the shell working directory.

ls - one of the most common commands in Linux. This command lists directory contents. It can also list permissions, owner, size etc. It sorts the file alphabetically by default.

Linux makes sure only proper people can have access to the proper files.
/Linux-Command-File-Permission/