Check output device is a terminal: Difference between revisions

=={{header|Standard ML}}==

<syntaxhighlight lang="sml">val stdoutRefersToTerminal : bool = Posix.ProcEnv.isatty Posix.FileSys.stdout</syntaxhighlight>

=={{header|Tcl}}==

To detect whether output is going to a terminal in Tcl, you check whether the <code>stdout</code> channel looks like a serial line (as those are indistinguishable from terminals). The simplest way of doing that is to see whether you can read the <tt>-mode</tt> or <code>-xchar</code> channel options, which are only present on serial channels:

{{trans|C}}

As there is currently no way to obtain this information via Wren CLI, we instead embed a Wren script in a C application and ask the host program to get it for us.

 

class C {

WrenVM* vm = wrenNewVM(&config);

const char* module = "main";

char *script = readFile(fileName);

WrenInterpretResult result = wrenInterpret(vm, module, script);

{{out}}

<pre>

Output device is a terminal = true

 

$ cat tmp

Output device is a terminal = false

 

Output device is a terminal = false

</pre>

=={{header|zkl}}==

On Unix, check to see if stdout's st_mode is a character device.