Every Android device comes with a born-shell and some commands.
Some commands are built-in into shell.
On you devices you can add additional shells and commands.
Every shell has a few built-in commands. Some common built-in commands are: - echo -- display a line of text. - set -- set or unset values of shell options and positional parameters. - export -- set export attribute for shell variables. - cd -- change the shell working directory. - pwd -- print name of current/working directory.
Environment variable PATH
The shell will run any command(program) found in PATH. The PATH is a colon (':') separated list of directories.
You can find out your shell's PATH by using the built-in echo command: