Shell one-liner

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Task
Shell one-liner
You are encouraged to solve this task according to the task description, using any language you may know.

Show how to specify and execute a short program in the language from a command shell, where the input to the command shell is only one line in length.

Avoid depending on the particular shell or operating system used as much as is reasonable; if the language has notable implementations which have different command argument syntax, or the systems those implementations run on have different styles of shells, it would be good to show multiple examples.

Contents

[edit] ACL2

$ acl2 <<< '(cw "Hello.")'

[edit] Ada

Works with: gnat

under a unixoid shell (bash, sh, ...)

echo 'with Ada.text_IO; use Ada.text_IO; procedure X is begin Put("Hello!"); end X;' > x.adb; gnatmake x; ./x; rm x.adb x.ali x.o x

Note that this mercilessly overwrites and later deletes any files x.adb, x.ali, x,o and x in the current directory.

[edit] Aikido

echo 'println ("Hello")' | aikido

[edit] Aime

$ src/aime -c 'o_text("Hello, World!\n");'

[edit] ALGOL 68

Works with: ALGOL 68G version Any - tested with release mk15-0.8b.fc9.i386 - Interpret straight off
$ a68g -e 'print(("Hello",new line))'

Output:

Hello
Works with: ELLA ALGOL 68 version Any - tested with release 1.8.8d.fc9.i386 - translate to C and then compile and run

For an ELLA ALGOL 68 one-liner, merge these lines of shell code:

code='print(("Hello", new line))'
a=/tmp/algol$$ s=/usr/share/algol68toc;
echo -e "PROGRAM algol$$ CONTEXT VOID\nUSE standard\nBEGIN\n$code\nEND\nFINISH\n" > $a.a68 &&
a68toc -lib $s -dir $s -uname TMP -tmp $a.a68 && rm $a.a68 &&
gcc $s/Afirst.o $a.c -l{a68s,a68,m,c} -o $a && rm $a.c &&
$a; rm $a

Output:

Hello

[edit] AWK

Maybe the most common way one can use awk is from the command line for one-liners, feeding the interpreter with an input.

$ awk 'BEGIN { print "Hello"; }'

A more "complex" and "real" example:

$ awk '/IN/ { print $2, $4; }' <input.txt

Select field 2 and 4 of lines matching the regular expression /IN/ (i.e. where IN appears)

[edit] BASIC

The name of the BASIC executable will vary (common ones are basic, bas, and bwbasic), but in general, a short program can be piped to the interpreter like any other language:

echo 'print "foo"'|basic

Note that under Windows (and presumably DOS) the two apostrophes (a.k.a. single quotes) should be omitted, since Windows doesn't remove them from the piped text (and the apostrophe is the comment character in many modern BASICs):

echo print "foo"|basic

Also, some popular interpreters (including Michael Haardt's bas and Chipmunk Basic) will include an extra prompt before exiting unless you include exit or system (depending on the specific interpreter's syntax). This sample output shows both with and without system in bas:

erik@satan:~$ echo 'print "foo"'|bas
bas 2.2
Copyright 1999-2009 Michael Haardt.
This is free software with ABSOLUTELY NO WARRANTY.
> foo
> erik@satan:~$ echo 'print "foo":system'|bas
bas 2.2
Copyright 1999-2009 Michael Haardt.
This is free software with ABSOLUTELY NO WARRANTY.
> foo
erik@satan:~$

Note that this is rather specific to Unix-like systems; most DOS and Windows interpreters are generally unable to handle programs in this manner, unless they were ported from a *nix system in the first place.

[edit] ZX Spectrum Basic

On the ZX Spectrum, the ROM basic allows direct commands to be entered from the system prompt:

PRINT "Hello World!"

[edit] Bracmat

This example uses the predefined function tay to make a taylor expansion of e^x.

DOS:

bracmat "put$tay$(e^x,x,20)&"

Linux:

bracmat 'put$tay$(e^x,x,10)&'

Output:

  1
+ x
+ 1/2*x^2
+ 1/6*x^3
+ 1/24*x^4
+ 1/120*x^5
+ 1/720*x^6
+ 1/5040*x^7
+ 1/40320*x^8
+ 1/362880*x^9
+ 1/3628800*x^10
+ 1/39916800*x^11
+ 1/479001600*x^12
+ 1/6227020800*x^13
+ 1/87178291200*x^14
+ 1/1307674368000*x^15
+ 1/20922789888000*x^16
+ 1/355687428096000*x^17
+ 1/6402373705728000*x^18
+ 1/121645100408832000*x^19
+ 1/2432902008176640000*x^20

[edit] Burlesque

 
Burlesque.exe --no-stdin "5 5 .+"
 

Using the official interpreter.

[edit] C

Works with: gcc

The following code leaves the file a.out in the current directory (it does not delete it to avoid to call another shell/system dependent command/program). The current directory is not specified by ./ in every system...

$ echo 'main() {printf("Hello\n");}' | gcc -w -x c -; ./a.out

[edit] C#

Note: whilst small, this is more than one line.

Requires PowerShell 2:

> Add-Type -TypeDefinition "public class HelloWorld { public static void SayHi() { System.Console.WriteLine(""Hi!""); } }"
> [HelloWorld]::SayHi()
Hi!

[edit] Clojure

Note: whilst small, this is more than one line.

clj-env-dir comes with clojure-contrib.

$ clj-env-dir -e "(defn add2 [x] (inc (inc x))) (add2 40)"
#'user/add2
42

[edit] CMake

This only works with Unix systems that have the device node /dev/stdin.

echo 'message(STATUS "Goodbye, World!")' | cmake -P /dev/stdin

[edit] Common Lisp

Varies by implementation

Works with: SBCL
sbcl --noinform --eval '(progn (princ "Hello") (terpri) (quit))'
Works with: CLISP
clisp.exe -q -x "(progn (format t \"Hello from CLISP\") (quit))"

[edit] D

Works with: D version 2

requires rdmd

rdmd --eval="writeln(q{Hello World!})"
Hello World!

[edit] Dc

dc -e '22 7/p'

[edit] E

rune --src.e 'println("Hello")'

The --src option ends with the the filename extension the provided type of program would have:

rune --src.e-awt 'def f := &lt;swing:makeJFrame>("Hello"); f.show(); f.addWindowListener(def _{to windowClosing(_) {interp.continueAtTop()} match _{}}); interp.blockAtTop()'

[edit] Emacs Lisp

emacs -batch -eval '(princ "Hello World!\n")' 

Or another example that does something useful: indent a C source file:

emacs -batch sample.c --eval '(indent-region (point-min) (point-max) nil)' -f save-buffer

[edit] Erlang

Erlang always starts other applications that can run in parallel in the background, and as such will not die by itself. To kill erl, we sequentially run the 'halt' function from the 'erlang' module (the -S is there to guarantee 'halt' will be evaluated after the io function).

$ erl -noshell -eval 'io:format("hello~n").' -s erlang halt
hello

[edit] F#

> echo printfn "Hello from F#" | fsi --quiet
Hello from F#

[edit] Factor

$ factor -run=none -e="USE: io \"hi\" print"

[edit] Forth

Works with: GNU Forth
$ gforth -e ".( Hello) cr bye"
Hello

[edit] Fortran

This example, stolen from the c example is subject to the same caveats. While contrived, FORTRAN as a one liner can easily handle some unique tasks. Let's plot a Bessel function:

 
$ gawk 'BEGIN{print"write(6,\"(2(g12.3,x))\")(i/10.0,besj1(i/10.0), i=0,1000)\nend";exit(0)}'|gfortran -ffree-form -x f95 - | gnuplot -p -e 'plot "<./a.out" t "Bessel function of 1st kind" w l'
 

Sorry, I don't know how to upload my jpeg file for the Image tag. Let's use the dumb display instead.

  0.6 +*------------+-------------+------------+-------------+------------++
      +**           +             +     Bessel function of 1st kind ****** +
  0.5 +**                                                                 ++
      |**                                                                  |
  0.4 +**                                                                 ++
      * *                                                                  |
  0.3 *+*   *                                                             ++
      * *  **   *                                                          |
  0.2 *+*  ***  **  **                                                    ++
  0.1 *+*  * *  **  **  ***  **  **   *   **   *                          ++
      * ** * * ***  **  * * ***  **  ***  **  **  ***  **  **  ***  **  ** |
    0 *+ * * * * *  * * * * * *  *** * * * *  *** * * ***  *** * * ***  ***+
      |  * * * * ***  * * * * ***  * * * * ***  *** * * **** *** *** ***  *|
 -0.1 ++ * * * *  **  *** ***  **  **  ***  **  **   **  **  **   **  **  **
      |  *** ***  **  **   **  **   *   *                                  |
 -0.2 ++ **   **  **                                                      ++
      |  **   *                                                            |
 -0.3 ++ **                                                               ++
      +  **         +             +            +             +             +
 -0.4 ++------------+-------------+------------+-------------+------------++
      0             20            40           60            80           100

[edit] Gema

$ gema -p '\B=Hello\n@end'
Hello

[edit] Go

Go is first of all a compiled language and currently comes with no support for running as a script language. The compiler and linker can of course be run from a command line shell, as in,

echo 'package main;func main(){println("hllowrld")}'>8.go;8g 8.go;8l 8.8;8.out

This will overwrite existing files in the current directory 8.go, 8.8, and 8.out, assuming of course, that the the current directory is even writable, and will leave these files behind after executing.

Running Go as a script language is a popular request however, and one of the better solutions currently is gorun. Gorun has solutions for the temporary file problem, writing to best-guess temporary directories by default and having an option to specify the location when this is needed or desired. Gorun still expects to read the source code from a file however, so you are on your own to deal with this before passing the file to gorun. Example,

echo 'package main;func main(){println("hllowrld")}'>/tmp/8.go;gorun /tmp/8.go

Output from either example:

hllowrld

[edit] Groovy

Works with: UNIX Shell
$ groovysh -q "println 'Hello'"
Hello
C:\Users\user> groovysh -q "println 'Hello'"
Hello

[edit] Haskell

$ ghc -e 'putStrLn "Hello"'
Hello

[edit] Icon and Unicon

These examples work with posix shells.

echo "procedure main();write(\"hello\");end" | icont - -x
echo "procedure main();write(\"hello world\");end" >hello.icn; unicon hello.icn -x

[edit] J

$ jconsole -js "exit echo 'Hello'"
Hello

That said, note that J interpreters can themselves be thought of as command shells.

[edit] Java

Works with: bash

These three lines work with Bourne Shell (or compatible) or C Shell (or compatible), or bash on Unix/Linux/MacOSX/Windows+cygwin

$ echo 'public class X{public static void main(String[]args){' \
> 'System.out.println("Hello Java!");}}' >X.java
$ javac X.java && java X

A user can also enter this as one (very long) line:

$ echo 'public class X{public static void main(String[]args){System.out.println("Hello Java!");}}'>X.java;javac X.java&&java X
Works with: MS-DOS
Compatible Environments (such as cmd.exe)

Works with cmd.exe on Windows (tested on Microsoft Windows XP [Version 5.1.2600])

C:\>echo public class X{public static void main(String[] args){System.out.println("Hello Java!");}}>X.java&&javac X.java&&java X
Hello Java!

[edit] JavaScript

Works with: SpiderMonkey
$ js -e 'print("hello")'
hello

[edit] Julia

$ julia -e 'for x in ARGS; println(x); end' foo bar
foo
bar

[edit] K

Works with: Kona
$ k -e "\`0: \"hello\\n\""

[edit] Lasso

From stdin:

echo " 'The date and time is: ' + date " | lasso9 --

Or alternatively:

$ lasso9 -s " 'The date and time is: ' + date "

[edit] Liberty BASIC

 
echo print "hello">oneLiner.bas & liberty -r oneLiner.bas echo print "hello">oneLiner.bas & liberty -r oneLiner.bas
 


[edit] Lua

lua -e 'print "Hello World!"'

[edit] Maple

maple -c'print(HELLO);' -cquit

[edit] Mathematica

echo Print[2+2] > file & math.exe -script file

[edit] NetRexx

Works with: UNIX Shell

Create a temporary file, execute the file via the NetRexx interpreter then delete the temporary file and any files generated via the translation. (i.e. Java class files etc.)

 
$ TNRX=`mktemp T_XXXXXXXXXXXX` && test ! -e $TNRX.* && (echo 'say "Goodbye, World!"' >$TNRX; nrc -exec $TNRX; rm $TNRX $TNRX.*; unset TNRX)
 

Output:

NetRexx portable processor, version NetRexx 3.01, build 40-20120823-0156
Copyright (c) RexxLA, 2011,2012.  All rights reserved.
Parts Copyright (c) IBM Corporation, 1995,2008.
Program T_dO7RQs5HPElq
===== Exec: T_dO7RQs5HPElq =====
Goodbye, World!
Processing of 'T_dO7RQs5HPElq' complete

[edit] NewLISP

newlisp -e "\"Hello\"
->"
Hello"

[edit] Nimrod

echo 'for i in 0..10: echo "Hello World"[0..i]' | nimrod i
>>> H
He
Hel
Hell
Hello
Hello 
Hello W
Hello Wo
Hello Wor
Hello Worl
Hello World
>>> 

[edit] Objeck

Works with: UNIX Shell
./obc -run '"Hello"->PrintLine();' -dest hello.obe ; ./obr hello.obe

[edit] OCaml

$ ocaml <(echo 'print_endline "Hello"')
Hello

[edit] Octave

$ octave --eval 'printf("Hello World, it is %s!\n",datestr(now));'
Hello World, it is 28-Aug-2013 17:53:47!

[edit] ooRexx

 
rexx -e "say 'Goodbye, world.'"
 

[edit] Oz

This is difficult to do in Oz because the compiler/interpreter always wants the source code in a file and does not read from stdin. We can do somethings like this on Unix-like systems:

echo >tmp.oz "{System.show hello}"; ozc -l System -e tmp.oz
hello

With -l System we make the System module available so that we can print something.

[edit] PARI/GP

echo "print(Pi)" | gp -q

[edit] Pascal

$ echo "begin writeln('Hello World') end." >OneLiner.pas; fpc -Fe/dev/null OneLiner.pas; ./OneLiner
Hello World

[edit] Perl

$ perl -e 'print "Hello\n"'
Hello

More information about the many ways of invoking perl can be found in perlrun.

[edit] Perl 6

Works with: Rakudo version #22 "Thousand Oaks"
$ perl6 -e 'say "Hello, world!"'
Hello, world!

[edit] PHP

assuming you have the PHP CLI (command-line interface) installed, not just the web server plugin

$ php -r 'echo "Hello\n";'
Hello

[edit] PicoLisp

$ picolisp -'prinl "Hello world!"' -bye
Hello world!

[edit] Pike

$ pike -e 'write("Hello\n");' 
Hello

[edit] PowerShell

> powershell -Command "Write-Host 'Hello'"
Hello

[edit] Prolog

[edit] Command-Line Options

$ swipl -g "writeln('hello world')." -t 'halt.'
hello world
$
$ gprolog --init-goal "write('goodbye'),nl,halt"
goodbye
$
$ yap -q -g "current_prolog_flag(dialect, D), writeln(D), halt"
yap

[edit] <<<

$ swipl -q <<< "current_prolog_flag(dialect,D), writeln(D), halt."
swi
 
$ yap -q <<< "current_prolog_flag(dialect,D), writeln(D), halt."
yap

[edit] Pipe

$ echo "current_prolog_flag(dialect,D), writeln(D), halt." | swipl -q
swi
 
$ echo "current_prolog_flag(dialect,D), writeln(D), halt." | yap -q
yap

[edit] PureBasic

Runs on Linux with(thanks to) bash. Path variables must be set as decribed in INSTALL.

$ echo 'messagerequester("Greetings","hello")' > "dib.pb" && ./pbcompiler dib.pb -e "dib" && ./dib

[edit] Python

[edit] Prints "Hello"

$ python -c 'print "Hello"'
Hello

[edit] Web server with CGI

The python CGIHTTPServer module is also an executable library that performs as a web server with CGI. to start enter:

python -m CGIHTTPServer

It returns with:

Serving HTTP on 0.0.0.0 port 8000 ...

[edit] R

$ echo 'cat("Hello\n")' | R --slave
Hello

Alternatively, using the Rscript front-end,

$ Rscript -e 'cat("Hello\n")'
Hello

[edit] Racket

$ racket -e "(displayln \"Hello World\")"
Hello World

[edit] REBOL

rebview -vswq --do "print {Hello!} quit" 

Output:

Hello!

[edit] Retro

echo '"hello\n" puts bye' | ./retro

[edit] REXX

Note: "Regina" is the only version of REXX that supports this type of behavior (taking it's input from a console stream).

 ┌────────────────────────────────────────────────┐
│ from the MS Windows® command line (cmd.exe)
└────────────────────────────────────────────────┘
 
echo do j=10 by 20 for 4;say right('hello',j);end | regina

output when using the (above) from the command line:

     hello
                         hello
                                             hello
                                                                 hello

[edit] Ruby

From Unix:

$ ruby -e 'puts "Hello"'
Hello
Works with: JRuby
$ jruby -e 'puts "Hello from JRuby"'
Hello from JRuby
Works with: Rubinius
$ rbx -e 'puts "Hello from Rubinius"'
Hello from Rubinius

[edit] Run BASIC

print shell$("echo hello world")

[edit] Scala

Library: Scala
C:\>scala -e "println(\"Hello\")"
Hello
 
PS C:\> scala -e 'println(\"Hello\")'
Hello

The escaping of quotes is required by Windows. On Unix and shown in the example on Windows PowerShell, one could just use single quotes around the code.

[edit] Scheme

Works with: Guile
guile -c '(display "Hello, world!\n")'

[edit] Shiny

shiny -e "say 'hi'" 

[edit] Slate

./slate --eval "[inform: 'hello'] ensure: [exit: 0].".

[edit] SNOBOL4

Portable version

echo 'a output = "Hello, World!";end' | snobol4 -b

Bash version

snobol4 -b <<<'a output = "Hello, World!";end'

[edit] Tcl

This is an area where Tcl is lacking, though when shell one-liners are required a construct like this is typically used:

$ echo 'puts Hello' | tclsh
Hello

[edit] TXR

$ echo 123-456-7890 | txr -c '@a-@b-@c' -
a="123"
b="456"
c="7890"
 

Most useful txr queries consist of multiple lines, and the line structure is important. Multi-liners can be passed via -c easily, but there is no provision in the syntax that would allow multi-liners to be actually written as one physical line. There are opposite provisions for splitting long logical lines into multiple physical lines.

The -e (evaluate) and -p (evaluate and print) options provide shell one-liner access to TXR Lisp:

$ txr -p '(+ 2 2)'
4
$ txr -e '(mkdir "foo" #o777)'
$ ls -ld foo
drwxrwxr-x 2 kaz kaz 4096 Mar 4 23:36 foo

[edit] UNIX Shell

Explicit call of the shell, passing the shell command via the -c option:

$ sh -c ls
$ sh -c "echo hello"

To invoke a specific shell like Bash, Korn Shell or Z Shell:

$ bash -c 'paste <(echo 1) <(echo 2)'
$ ksh -c 'let i=3+4; print $i'
$ zsh -c 'if [[ 5 -lt 6 ]] { echo ok };'

Shell scripts almost never use sh -c, because there are various implicit ways whereby the shell command language evaluates a command in a subshell:

$ VAR=`echo hello`   # obsolescent backtick notation
$ VAR=$(echo hello) # modern POSIX notation
$ (echo hello) # execute in another shell process, not in this one

There are more details about `echo hello` and $(echo hello) at Execute a system command#UNIX Shell.

[edit] C Shell

Run a C shell command from any shell:

$ csh -fc 'if (5 < 6) echo ok'

[edit] es

Run a command, in extensible shell, from any shell:

$ es -c 'if {test 5 -lt 6} {echo ok}'

[edit] Ursala

The command to execute the Ursala compiler is fun. An expression supplied as a parameter to the --main option is compiled and evaluated. If the expression evaluates to a list of character strings, it can be displayed on standard output with --show. If it's some other type, it can be formatted for display by --cast <type expression>,

$ fun --main=-[hello]- --show
hello
$ fun --main="power/2 32" --cast %n
4294967296
$ fun --m="..mp2str mpfr..pi 120" --c %s
'3.1415926535897932384626433832795028847E+00'

[edit] Vedit macro language

The following DOS command starts Vedit and displays a message. When the user presses any key, Vedit exits.

vpw -c'Get_Key("Hello!") exit'

[edit] Wart

echo "prn 34" |wart

[edit] zkl

With a unix like shell, just pipe the program into the REPL. Kinda greasy and noisy. To shut it up, send stdout to /dev/null

echo 'println("Hello World ",5+6)' | zkl
Output:
zkl 1.12.9, released 2014-05-01
Hello World 11
Hello World 11
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