PATH determines what binaries are known, colon delimited defining the order of looking for commands

Shims are executables that can intercept commands and change arguments, handle the operation, or redirect the operation

curl

Tool for transferring data from or onto a server, can use almost all protocols

nc

Netcat is a computer networking utility for reading and writing to network connections using TCP or UDP

• used as a dependable backend
• nc -l 9292 opens a port at 9292

ssh

For logging into remote machines. ssh hostname

• connects and logs into the specified hostname

man

Manual pages for any command line tool. man some-command pulls up help info about a command.

touch a b c

Creates or updates last write date of files a, b and c.

echo

Echo is a print cmd to standard output. Takes arguments and prints them delimited by spaces. alternatively, can take a literal string using quotes.

$ echo Some      Test
Some Test
$ echo "Some      Test"
Some      Test

source

Evaluates the file (could be a shell script for example) following the command, as a list of commands, executed in current context.

builtin

builtin commands are contained within the shell itself. Does not invoke another program.

Find

For finding files. Allows user to execute other commands on them. In the following cmd, pattern describes a glob pattern for finding files:

find . -name "pattern" -print