Two ways to execute the Linux command by "Erlang"

os.cmd (cmd)

The OS module provides the CMD function to execute Linux system shell commands (you can also execute Windows commands). Returns the standard output string result of a cmd command. For example, execute Os:cmd ("date") on a Linux system. Time to return to Linux. This is relatively simple and, in general, satisfies most of the requirements.

Erlang:open_port (PortName, portsettings)

When Os.cmd (CMD) does not meet your needs, you can use the powerful Open_port (PortName, portsettings) to solve. The simplest requirement, I want to execute a Linux command, but also need to return the exit code. Os.cmd (CMD) is a bit nasty. Also do not think that with Open_port (PortName, portsettings) can completely replace the os.com (CMD). It takes a price to be strong.

Percent benefit: You can return to exit status and the execution process
Percent disadvantage: very affect performance, open_port execution, BEAM.SMP will block

It is not recommended to use Erlang:open_port (PortName, Portsettings) when the performance requirements of the system are relatively high.

Here is a very useful code that returns the exit status and execution results.

My_exec (Command)Port=Open_port ({spawn, Command}, [Stream, in, EOF, hide, Exit_status]), Result=Get_data (port, []), Result.get_data (port, Sofar)-Receive{Port, {data, Bytes}}-Get_data (Port, [Sofar|Bytes]); {Port, EOF}-Port!{self (), close},Receive{Port, closed}-true        End,        Receive        {' EXIT ', Port, _}OK After1,%Force Context Switch OKEnd, ExitCode=Receive{Port, {exit_status, Code}}-CodeEnd, {ExitCode, Lists:flatten (SOFAR)}End.

Reference Documentation:

Http://erlang.org/doc/man/os.html#cmd-1

Http://erlang.org/doc/man/erlang.html#open_port-2

Two ways to execute the Linux command by "Erlang"