system

dos

unix

Shell command execution.

Syntax

• status = system(command)
• status = system(command, timeout)
• status = dos(command)
• status = unix(command)
• status = unix(commands)
• [status, output, duration] = system(command)
• [status, output, duration] = dos(command)
• [status, output, duration] = unix(command)
• [status, output, duration] = system(command, '-echo')
• [status, output, duration] = dos(command, '-echo')
• [status, output, duration] = unix(command, '-echo')
• [s, outputs, duration] = unix(commands)
• [s, outputs, duration] = unix(commands, timeouts)

Input argument

• command - a string: command to execute in command shell.
• commands - a cell of string or a string array: commands to execute in command shell in parallel.
• timeout - an integer value (scalar): kill process using timeout in seconds.
• timeouts - an integer value (scalar: applied to all commands or vector: one by command): kill process using timeout in seconds.

Output argument

• status - an integer value: exit code value of the command.
• output - a string: output of the command.
• duration - integer value: duration (milliseconds).
• s - an matrix of integer value: exit code value of the commands (same dimensions than commands).
• output - a string array: output of the commands.
• duration - an matrix of integer value: duration of each execution (milliseconds).

Description

system sends a string to the operating system for execution. Standard output and standard errors of the shell command are written in the calling shell.

[status, output] = system(command, '-echo') forces the output to the Command Window, even though it is also being assigned into a variable.

Callback functions cannot be called until system command is not finished.

Nelson will convert characters to the encoding that your operating system shell accepts (ANSI on Windows by default, UTF-8 on others systems).

command can be interrupted with CTRL-C key, in this case status code returned will be 258 (WAIT_TIMEOUT) on Windows and 134 on others platforms (128 + SIGABRT)output contains 'ABORTED'.

if timeout value is 0. timeout disabled.

Examples

[s,w] = system('dir');
[s,w] = system('dir','-echo');

[s,w] = system(["echo hello", "dir", "echo world"])

tic();[s, w, d] = system(["PING -n 5 127.0.0.1>nul", "PING -n 7 127.0.0.1>nul", "PING -n 10 127.0.0.1>nul"]), toc()

tic();[s, w, d] = system(["PING -n 5 127.0.0.1>nul", "PING -n 7 127.0.0.1>nul", "PING -n 10 127.0.0.1>nul"], [1, 5, 3]), toc()

To detach an system command, include the trailing character, &, in the command argument.

[s,w] = system('notepad &');

See also

winopen.

History

Author

Allan CORNET