Xing's Blog

whereis - locate the binary, source, and manual page files for a command

which - Locate a program in the user’s path.

tail - output the last part of files.

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.