Get system command output: Difference between revisions

<langsyntaxhighlight Adalang="ada">with Ada.Text_IO; use Ada.Text_IO;

end System_Command;</langsyntaxhighlight>

<langsyntaxhighlight lang="aime">o_("-- ", sshell().plan("expr", "8", "*", "9").link.b_dump('\n'), " --\n");</langsyntaxhighlight>

}</langsyntaxhighlight>

=={{header|BaConBASIC}}==

PRINT "First word: " & TOKEN$(result$, 1)</langsyntaxhighlight>

<langsyntaxhighlight lang="dos">

<langsyntaxhighlight lang="cpp">#include <fstream>

}</langsyntaxhighlight>

<langsyntaxhighlight lang="clojure">(use '[clojure.java.shell :only [sh]])

(sh "echo" "Hello")</langsyntaxhighlight>

<langsyntaxhighlight lang="lisp">(trivial-shell:shell-command "uname -imp")</langsyntaxhighlight>

<langsyntaxhighlight lang="lisp">(defparameter *my-proc*

(read-line (sb-ext:process-output *my-proc*) nil)</langsyntaxhighlight>

<langsyntaxhighlight lang="lisp">(uiop:run-program '("ls" "-l" "-a") :output :string)</langsyntaxhighlight>

<langsyntaxhighlight Dlang="d">import std.process;

}</langsyntaxhighlight>

<langsyntaxhighlight lang="factor">USING: io.encodings.utf8 io.launcher ;

"echo hello" utf8 [ contents ] with-process-reader .</langsyntaxhighlight>

<langsyntaxhighlight lang="freebasic">' FB 1.05.0 Win64

End</langsyntaxhighlight>

<langsyntaxhighlight lang="gambas">Public Sub Main()

End</langsyntaxhighlight>

<langsyntaxhighlight lang="genie">[indent=4]

stderr.printf("%s\n", e.message)</langsyntaxhighlight>

<langsyntaxhighlight lang="go">package main

}</langsyntaxhighlight>

<langsyntaxhighlight lang="haskell">#!/usr/bin/env stack

mapM_ (putStrLn . reverse) results</langsyntaxhighlight>

<langsyntaxhighlight lang="unicon">#

end</langsyntaxhighlight>

<langsyntaxhighlight Jlang="j"> require 'task'

└─────────────────────┘</langsyntaxhighlight>

Caution: I have sometimes seen some versions of linux refuse to execute subshells after a few hundred thousand shell commands (the exec system call fails). I've not found any satisfying documentation on why this happens, but I strongly suspect kernel memory fragmentation (the examples where this happened were also using a lot of memory to accumulate results and it happened much more frequently anon machines with little memory than on machines with more memory). Exiting J and starting a new process has cleared it up when it has happened. AnywaysWhen that becomes an issue, I usually prefer to do that kindsubshell ofresult processingcapture before J starts, just to be safe.

<langsyntaxhighlight lang="java">import java.io.*;

}</langsyntaxhighlight>

<langsyntaxhighlight lang="javascript">var commandOutput = exec('ls -gocart', { retAll:true });

puts(commandOutput.data);</langsyntaxhighlight>

-rw-rw-r--. 1 155 Feb 8 07:52 JSON.jsi</pre>

<langsyntaxhighlight lang="julia">ls = readstring(`ls`)</langsyntaxhighlight>

<langsyntaxhighlight lang="julia">ll = readlines(`ls -l`)</langsyntaxhighlight>

<langsyntaxhighlight lang="scala">// version 1.0.6

}</langsyntaxhighlight>

<langsyntaxhighlight lang="lingo">sx = xtra("Shell").new()

<snip>"</langsyntaxhighlight>

<langsyntaxhighlight Lualang="lua">local output = io.popen("echo Hurrah!")

print(output:read("*all"))</langsyntaxhighlight>

<langsyntaxhighlight ActionScriptlang="actionscript">/* Get system command output, neko */

sys_exit(ps);</langsyntaxhighlight>

<langsyntaxhighlight lang="nim">import osproc

<langsyntaxhighlight ooRexxlang="oorexx">/* Execute a system command and retrieve its output into a stem. */

exit ls_rc</langsyntaxhighlight>

<langsyntaxhighlight lang="oorexx">cmd='dir tu*.rex /od'

End </langsyntaxhighlight>

<langsyntaxhighlight lang="oorexx">dir='dir.dir'

Call lineout oid</langsyntaxhighlight>

<langsyntaxhighlight lang="parigp">externstr("time/t")</langsyntaxhighlight>

=={{Headerheader|Perl}}==

<langsyntaxhighlight lang="perl">my @directories = grep { chomp; -d } `ls`;

}</langsyntaxhighlight>

<langsyntaxhighlight lang="perl">my $command = shift or die "No command supplied\n";

my @output_and_errors = qx/$command 2>&1/ or die "Couldn't execute command\n";</langsyntaxhighlight>

<langsyntaxhighlight lang="perl">use autodie;

}</langsyntaxhighlight>

=={{header|Perl 6Phix}}==

<langsyntaxhighlight PicoLisplang="picolisp">: (in '(uname "-om") (line T))

-> "aarch64 Android"</langsyntaxhighlight>

<langsyntaxhighlight lang="python">>>> import subprocess

>>> # Ref: https://docs.python.org/3/library/subprocess.html</langsyntaxhighlight>

<langsyntaxhighlight lang="rsplus">

This demonstrates one function: <code>system</system></code>. It is the simplest of a family of commands in the <code>racket/system</code> collection.

<langsyntaxhighlight lang="racket">#lang racket/base

=> (values #t "foo" "bar\n"))</langsyntaxhighlight>

<langsyntaxhighlight lang="rexx">/*REXX program executes a system command and displays the results (from an array). */

exit 0 /*stick a fork in it, we're all done. */</langsyntaxhighlight>

<langsyntaxhighlight lang="ring">

<langsyntaxhighlight lang="runbasic">a$ = shell$("dir") ' Returns the directory info into a$

<langsyntaxhighlight lang="rust">use std::process::Command;

}</langsyntaxhighlight>

<langsyntaxhighlight lang="scala">import scala.io.Source

println(sc.mkString)</langsyntaxhighlight>

<langsyntaxhighlight lang="ruby">var output = `ls` # `output` is a string

var lines = `ls`.lines # `lines` is an array</langsyntaxhighlight>

<langsyntaxhighlight lang="ruby">var pipe = %p(ls) # same as: Pipe('ls')

pipe_h.each { |line| lines << line }</langsyntaxhighlight>

<langsyntaxhighlight lang="stata">program shellout, rclass

end</langsyntaxhighlight>

<langsyntaxhighlight lang="stata">. shellout dir /b *.dta

Python 3.6.2</langsyntaxhighlight>

<langsyntaxhighlight Swiftlang="swift">import Foundation

print(output!)</langsyntaxhighlight>

<langsyntaxhighlight lang="tcl">set data [exec ls -l]

puts "read [string length $data] bytes and [llength [split $data \n]] lines"</langsyntaxhighlight>

<langsyntaxhighlight lang="tcl">set data [exec {*}[auto_execok DIR]]</langsyntaxhighlight>

<langsyntaxhighlight lang="tcl"># This syntax is pretty ugly, alas

close $pipe</langsyntaxhighlight>

<langsyntaxhighlight lang="ursa">> decl iodevice iod

> </langsyntaxhighlight>

<langsyntaxhighlight lang="zkl">zkl: System.cmd("date >foo.txt")

Wed Aug 20 00:28:55 PDT 2014</langsyntaxhighlight>