Check input device is a terminal: Difference between revisions

{{task}}

 

*   [[Check output device is a terminal]]

<br><br>

=={{header|Ada}}==

{{works with|GNAT}}

We use the interface to C library functions <code>isatty()</code> and <code>fileno()</code>.

 

with Interfaces.C_Streams; use Interfaces.C_Streams;

 

</pre>

 

PRINT terminal</syntaxhighlight>

 

prompt$ ./istty <<<"testing"

0</pre>

 

=={{header|C}}==

Use <code>isatty()</code> on file descriptor to determine if it's a TTY. To get the file descriptor from a <code>FILE*</code> pointer, use <code>fileno</code>:

#include <stdio.h> //for fileno()

 

stdin is not tty

</pre>

=={{header|COBOL}}==

Works with GnuCOBOL.

 

*> istty, check id fd 0 is a tty

*> Tectonics: cobc -xj istty.cob

fd 0 tty: +0000000000

fd 2 tty: +0000000000</pre>

=={{header|Common Lisp}}==

{{Works with|SBCL}}

(format T "stdin is~:[ not~;~] a terminal~%"

(interactive-stream-p s)))</syntaxhighlight>

$ echo "" | sbcl --script rc.lisp

stdin is not a terminal</pre>

=={{header|Crystal}}==

File.new("/dev/tty").tty? #=> true

STDIN.tty? #=> true</syntaxhighlight>

=={{header|D}}==

 

extern(C) int isatty(int);

 

 

 

</syntaxhighlight>

 

 

=={{header|Go}}==

{{libheader|Go sub-repositories}}

 

import (

Who are you? You're not a terminal.

</pre>

 

=={{header|Haskell}}==

Example uses [https://hackage.haskell.org/package/unix <tt>unix</tt>] package:

 

import System.Posix.IO (stdInput)

then "stdin is TTY"

else "stdin is not TTY"</syntaxhighlight>

=={{header|Jsish}}==

;Interp.conf().subOpts.istty;

 

prompt$ jsish --U checkInputDevice.jsi

Interp.conf().subOpts.istty ==> false</pre>

=={{header|Julia}}==

if isa(STDIN, Base.TTY)

println("This program sees STDIN as a TTY.")

This program sees STDIN as a TTY.

</pre>

=={{header|Kotlin}}==

{{Works with|Ubuntu|14.04}}

 

import platform.posix.*

stdin is a terminal

</pre>

=={{header|Nemerle}}==

There is no explicit way (ie <tt>isatty()</tt>)to do this; however, if we ''assume'' that standard input ''is'' a terminal, we can check if the input stream has been redirected (presumably to something other than a terminal).

=={{header|Nim}}==

Using function "isatty" of standard module "terminal" which accepts a File as argument.

 

 

echo if stdin.isatty: "stdin is a terminal" else: "stdin is not a terminal"</syntaxhighlight>

<pre>Command: ./check_input_dev <somefile

Result: stdin is not a terminal</pre>

=={{header|OCaml}}==

 

print_endline (

if Unix.isatty Unix.stdin

Input doesn't come from tty.

</pre>

=={{header|Ol}}==

(define (isatty? fd) (syscall 16 fd 19))

(print (if (isatty? stdin)

"Input doesn't come from tty."))

</syntaxhighlight>

=={{header|Perl}}==

use warnings;

use 5.010;

$ true | perl istty.pl

Input doesn't come from tty.

=={{header|Phix}}==

<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (no input redirection in a browser!)</span>

<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"stdin:%t, stdout:%t, stderr:%t\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">isatty</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">),</span><span style="color: #000000;">isatty</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">),</span><span style="color: #000000;">isatty</span><span style="color: #0000FF;">(</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)})</span>

stdin:false, stdout:true, stderr:true

</pre>

=={{header|Pike}}==

{

if(Stdio.Terminfo.is_tty())

$ echo | ./istty.pike

Input doesn't come from tty.</pre>

=={{header|Python}}==

if stdin.isatty():

print("Input comes from tty.")

$ true | python istty.py

Input doesn't come from tty.

=={{header|Quackery}}==

 

{{trans|Python}}

 

to_stack( 1 if stdin.isatty() else 0)|

python ] is ttyin ( --> b )

 

<pre>Looks like a teletype.</pre>

=={{header|Racket}}==

(terminal-port? (current-input-port))

</syntaxhighlight>

=={{header|Raku}}==

(formerly Perl 6)

{{works with|Rakudo|2015.12}}

 

$ raku istty.raku

$ true | raku istty.raku

Input doesn't come from tty.

=={{header|REXX}}==

 

if queued() then say 'input comes from the terminal.'

/*stick a fork in it, we're done.*/

</syntaxhighlight>

=={{header|Ring}}==

# Project : Check input device is a terminal

input redirected

</pre>

=={{header|Ruby}}==

Example from the docs.

File.new("/dev/tty").isatty #=> true</syntaxhighlight>

=={{header|Rust}}==

 

extern crate libc;

}

}</syntaxhighlight>

=={{header|Scala}}==

{{Works with|Ubuntu|14.04}}

 

object IsATty extends App {

println("tty " + apply(true))

}</syntaxhighlight>

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

=={{header|Tcl}}==

Tcl automatically detects whether <tt>stdin</tt> is coming from a terminal (or a socket) and sets up the channel to have the correct type. One of the configuration options of a terminal channel is <tt>-mode</tt> (used to configure baud rates on a real serial terminal) so we simply detect whether the option is present.

puts "Input doesn't come from tty."

} else {

Input doesn't come from tty.

</pre>

=={{header|UNIX Shell}}==

 

if [ -t 0 ]

fi</syntaxhighlight>

 

=={{header|Wren}}==

 

System.print("Input device is a terminal? %(Stdin.isTerminal ? "Yes" : "No")")</syntaxhighlight>

=={{header|zkl}}==

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

fcn S_ISCHR(f){ f.info()[4].bitAnd(S_IFCHR).toBool() }

S_ISCHR(File.stdin).println();</syntaxhighlight>

False

</pre>

{{omit from|Clojure}}

{{omit from|Java|See bug JDK-4099017}}

{{omit from|Processing}}

{{omit from|TI-83 BASIC|Input device is always either a terminal or created by the program}}

{{omit from|ZX Spectrum Basic}}