How to action a command from a PHP script in the current CLI context?

Question

Suppose I have a PHP script that prints time.

echo time() . "\r\n";

Executing this script several times in CLI will look like this:

curiosity:bin gajus$ php -r 'echo time() . "\r\n";'
1434453316
curiosity:bin gajus$ php -r 'echo time() . "\r\n";'
1434453318
curiosity:bin gajus$ php -r 'echo time() . "\r\n";'
1434453319
curiosity:bin gajus$

I want my PHP script to print printf '\e\]50;ClearScrollback\a' sequence that would clear iTerm2 scrollback. I have tried variations of php -r 'echo "\e\]50;ClearScrollback\a" .time() . "\r\n";' but that just spits the string to the CLI output:

curiosity:bin gajus$ php -r 'echo "\e\]50;ClearScrollback\a" .time() . "\r\n";'
]50;ClearScrollback\a1434453543
curiosity:bin gajus$

Is there a way to trigger CLI ClearScrollback from within PHP script?

Try this: http://stackoverflow.com/questions/24327544/how-can-clear-screen-in-php-cli-like-cls-command — Raja Amer Khan, Jun 16 '15 at 11:33

score 0 · Accepted Answer · edited Jun 16 '15 at 16:32

0

The escape code ^[]50;ClearScrollback^G itself is described in Proprietary Escape Codes iTerm2 documentation.

A quick comment on notation: in this document, ^[ means "Escape" (hex code 0x1b) and ^G means "bel" (hex code 0x07).

You can use PHP chr() function, e.g.

php -r 'echo chr(27) . "]50;ClearScrollback" . chr(7);'

The chr function returns a specific ascii character. In this example I am using ASCII control characters "escape" (27) and "bell" (7). It is a cross-platform safe method to describe ascii control characters.

edited Jun 16 '15 at 16:32

Gajus

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answered Jun 16 '15 at 11:55

Samuel

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This prints the output, as it should, but does not trigger the command in CLI. https://gist.github.com/gajus/427c1314e58c326e90d7 – Gajus Jun 16 '15 at 12:47
Your suggestion using `exec` executes an external program, as opposed to triggering a change in the current CLI session. – Gajus Jun 16 '15 at 14:39
Ok, check the modified answer – Samuel Jun 16 '15 at 15:16
@Samule This works. Please, can you explain why does it work? Does a terminal such as iTerm interpret literally all of the program output and suppose it contains is an escape code, it will execute it? – Gajus Jun 16 '15 at 16:23
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I have edited your answer to include explanation as I understand it. I trust that you will correct it if I am wrong about anything. – Gajus Jun 16 '15 at 16:33
For my own future references (and possibly useful to others too), a simple PHP function to detect the terminal type and action the corresponding equivalent of clear scrollback. https://gist.github.com/gajus/2f2d7cb9c674a8b8e86c – Gajus Jun 17 '15 at 14:54

How to action a command from a PHP script in the current CLI context?

1 Answers1