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Write a piece of code that takes a string as input, and outputs a piece of code in the same language that, when run, will output the initial input string.

It must be able to handle any combination of characters A-Z, a-z, and 0-9.

Example in Python:

import sys
print "print('" + sys.argv[1] + "')"

Given the input of testing123, it will return print('testing123').

Since this is , the shortest answer in bytes will win.

totallyhuman
17.4k3 gold badges34 silver badges89 bronze badges
asked Aug 13, 2017 at 19:31
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12
  • \$\begingroup\$ Can it be a function? \$\endgroup\$ Commented Aug 13, 2017 at 19:34
  • \$\begingroup\$ @manatwork (S)he edited it just now. \$\endgroup\$ Commented Aug 13, 2017 at 19:42
  • \$\begingroup\$ Must input be a string? Or can it be an integer? \$\endgroup\$ Commented Aug 13, 2017 at 19:48
  • \$\begingroup\$ Must be able to handle both integer and string inputs. \$\endgroup\$ Commented Aug 13, 2017 at 20:00
  • 2
    \$\begingroup\$ Can we output a function as per the defauts on meta? \$\endgroup\$ Commented Aug 14, 2017 at 18:26

79 Answers 79

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pl, 0 bytes

Code:



Try it online! 


Explanation:


An empty program in pl is simply a cat program, outputting the exact same as the input.


In pl, all ASCII characters are essentially variables, but when the variable doesn't exist (yet), pl assumes that they are part of a string.

 

 

 

 
 
 
 

 

 

 

 answered Aug 13, 2017 at 19:59
 

 
 

 
 


 

 

 
 
 

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 I knew there was a language like this, couldn't find it though :(
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 Commented
 Aug 13, 2017 at 20:00
 
 
    
 
    
 
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 \$\begingroup\$
 In the same vein, see Cat, which is an interpreted language like Python. Most modern Linux distros ship with a cat interpreter. ;)
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 Commented
 Aug 13, 2017 at 20:31
 
 
    
 
    
 
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 This solution also works for /// if you consider input to be appended to the program source code (since /// has no mechanism for input). /// is one of many languages (I think) where alphanumeric characters at the beginning of the program are simply output.
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 Commented
 Aug 14, 2017 at 7:22
 
 
    
 
    
 
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 Can you post the ungolfed version? ;)
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 Commented
 Aug 15, 2017 at 13:16
 
 
    
 
    
 
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brainfuck, (削除) 56 (削除ここまで) (削除) 55 (削除ここまで) 33 bytes


1 byte saved thanks to Gravitron, and 22 bytes saved thanks to Jo King!


--[>+<++++++],[[->.<]>+++.--.-<,]



Try it online! 


Output requires an interpreter that wraps on memory underflow and has EOI=0. TIO has such an interpreter.


Explanation


--[>+<++++++] initializes the tape with a single +.


The input loop:


,[[->.<]>+++.--.-<,]
, take input
 [ ,] while input is nonzero:
 [->.<] output `+` input times
 >+++. output `.` (`+` + 3)
 --. output `,` (`.` - 2)
 -< restore `+` and move back to input



Other solutions


Each line is its own solution.


+++[>+++++<-]>[>++++>+++<<-]>>-->,[[-<.>]<+++.---<.>>,]
--[>+<++++++],[[->.<]>+++.++++++++++++++++.-------------------<,]
++++++++++[>++++++>++++>++++<<<-]>>+++>++++++>,[[-<<.>>]<.<<.>>>,]
++++++++++[>++++++>++++>++++<<<-]>++>+++>++++++>,[[-<<.>>]<.<<.>>>,]


 

 

 

 
 
 
 

 

 

 

 answered Aug 13, 2017 at 20:49
 

 
 

 
 


 

 

 
 
 

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 +1. I don't know Brainfuck, but I can't imagine trying to solve a problem like this with it.
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 Commented
 Aug 13, 2017 at 21:14
 
 
    
 
    
 
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 You can save 1 byte by replacing the +++++++++++++++ with +++[>+++++<-]> (From brainfuck constants)
 \$\endgroup\$
 
 
 
 Commented
 Aug 13, 2017 at 21:45
 
 
 
 
 
    
 
    
 
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 @Graviton Oh, cool, thanks
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 Commented
 Aug 13, 2017 at 21:51
 
 
    
 
    
 
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 you didn't replace it in the explanation
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 Commented
 Aug 14, 2017 at 5:24
 
 
    
 
    
 
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 You don't know Brainfuck? I'll teach you in one comment! We start on a tape of 0's, with a pointer to a value. + increments the value, - decrements the value, > moves the pointer right, < moves the pointer left, , reads input to the pointer as an ASCII character, . outputs the value of the pointer as an ASCII character, [ starts a loop, and ] jumps to the corresponding [ if the value of the pointer is not 0. I'm bad at explaining, but that's how easy Brainfuck is. And Nice golf Conor!
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 Commented
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Take District Line to Barking
Take District Line to Hammersmith
Take Circle Line to Paddington
Take Circle Line to Bank
Take Circle Line to Barbican
Take Circle Line to Bank
Take Circle Line to Hammersmith
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Take Circle Line to Bank
Take District Line to West Ham
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Take Circle Line to Paddington
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Take Circle Line to Wood Lane
Take Circle Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Aldgate
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Take Circle Line to Aldgate
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Take Circle Line to Paddington
Take District Line to Barking
Take District Line to Paddington
Take Circle Line to Bank
Take District Line to Barking
Take District Line to Hammersmith
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Take Circle Line to Bank
Take District Line to Barking
Take District Line to Bank
Take Circle Line to Hammersmith
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Take Circle Line to Paddington
Take Circle Line to Moorgate
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Take Circle Line to Bank
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Take Circle Line to Hammersmith
Take Circle Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Bank
Take Central Line to Chancery Lane
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Take Circle Line to Hammersmith
Take Circle Line to Paddington
Take Circle Line to Paddington
Take District Line to Barking
Take District Line to Paddington
Take Circle Line to Westminster
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Take District Line to Plaistow
Take District Line to Bank
Take Circle Line to Moorgate
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Take Circle Line to Bank
Take Circle Line to Paddington
Take Circle Line to Westminster
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Take District Line to Mile End
Take Central Line to Bank
Take Circle Line to Aldgate
Take Circle Line to Bank
Take Circle Line to Hammersmith
Take District Line to Gunnersbury
Take District Line to Bank
Take Circle Line to Westminster
Take Circle Line to Bank
Take Circle Line to Hammersmith
Take District Line to Gunnersbury
Take District Line to Mile End
Take Central Line to Bank
Take Circle Line to Bank
Take Northern Line to Charing Cross
Take Northern Line to Charing Cross
Take Northern Line to Bank
Take Circle Line to Tower Hill
Take Circle Line to Hammersmith
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Hammersmith
Take Circle Line to Notting Hill Gate
Take Circle Line to Notting Hill Gate
Take District Line to Upminster
Take District Line to Tower Hill
Take Circle Line to Bank
Take Circle Line to Temple
Take Circle Line to Bank
Take Circle Line to Bayswater
Take Circle Line to Bank
Take Circle Line to Hammersmith
Take Circle Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Bank
Take Circle Line to Bayswater
Take Circle Line to Tower Hill
Take Circle Line to Bank
Take Circle Line to Hammersmith
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Hammersmith
Take Circle Line to Notting Hill Gate
Take Circle Line to Notting Hill Gate
Take District Line to Upminster
Take District Line to Bank
Take Circle Line to Hammersmith
Take Circle Line to Embankment
Take Circle Line to Hammersmith
Take Circle Line to Tower Hill
Take Circle Line to Bank
Take Circle Line to Embankment
Take Northern Line to Angel
Take Northern Line to Bank
Take Central Line to Marble Arch
Take Central Line to Bank
Take Circle Line to Bank
Take Circle Line to Westminster
Take District Line to Upminster
Take District Line to Bank
Take Circle Line to Aldgate
Take Circle Line to Bank
Take Circle Line to Hammersmith
Take District Line to Upminster
Take District Line to Bank
Take Circle Line to Aldgate
Take Circle Line to Hammersmith
Take District Line to Gunnersbury
Take District Line to Mile End
Take Central Line to Bank
Take Circle Line to Aldgate
Take Circle Line to Bank
Take Circle Line to Hammersmith
Take District Line to Mile End
Take Central Line to Bank
Take Circle Line to Bank
Take Northern Line to Charing Cross
Take Northern Line to Charing Cross
Take Northern Line to Bank
Take Circle Line to Tower Hill
Take Circle Line to Hammersmith
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Hammersmith
Take Circle Line to Notting Hill Gate
Take Circle Line to Notting Hill Gate
Take District Line to Upminster
Take District Line to Embankment
Take Circle Line to Bank
Take Circle Line to Hammersmith
Take Piccadilly Line to Bounds Green
Take Piccadilly Line to Hammersmith
Take Circle Line to Embankment
Take Circle Line to Bank
Take Circle Line to Hammersmith
Take Circle Line to Cannon Street
Take Circle Line to Hammersmith
Take Circle Line to Cannon Street
Take District Line to Acton Town
Take District Line to Acton Town
Take Piccadilly Line to Bounds Green
Take Piccadilly Line to Holborn
Take Central Line to Holborn
Take Central Line to Bank
Take Circle Line to Hammersmith
Take District Line to West Ham
Take District Line to Bank
Take Circle Line to Aldgate
Take Circle Line to Aldgate
Take Metropolitan Line to Chalfont & Latimer
Take Metropolitan Line to King's Cross St. Pancras
Take Victoria Line to Seven Sisters
Take Victoria Line to Euston
Take Victoria Line to Euston
Take Northern Line to Bank
Take Circle Line to Hammersmith
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Bank
Take Circle Line to Tower Hill
Take Circle Line to Bank
Take Circle Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Stepney Green
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Stepney Green
Take Hammersmith & City Line to Moorgate
Take Circle Line to Moorgate
Take Metropolitan Line to Chalfont & Latimer
Take Metropolitan Line to Moorgate
Take Circle Line to Moorgate
Take Circle Line to Bank
Take Circle Line to Bank
Take District Line to Upminster
Take District Line to Bank
Take Circle Line to Tower Hill
Take Circle Line to Bank
Take Circle Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Hammersmith
Take Piccadilly Line to Russell Square
Take Piccadilly Line to Russell Square
Take Piccadilly Line to Acton Town
Take District Line to Acton Town
Take District Line to Bank
Take Circle Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Gunnersbury
Take District Line to Bank
Take District Line to East Ham
Take District Line to Bank
Take Circle Line to Hammersmith
Take District Line to Gunnersbury
Take District Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Bank
Take District Line to East Ham
Take District Line to Tower Hill
Take Circle Line to Bank
Take District Line to West Ham
Take District Line to Bank
Take Circle Line to Bank
Take Northern Line to Angel
Take Northern Line to Bank
Take Circle Line to Moorgate
Take Circle Line to Bank
Take Circle Line to Hammersmith
Take Circle Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Bank
Take Circle Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Barbican
Take Circle Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Moorgate
Take Circle Line to Bank
Take Northern Line to Morden
Take Northern Line to Bank
Take Circle Line to Bank
Take District Line to Gunnersbury
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Gunnersbury
Take District Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Victoria
Take Victoria Line to Seven Sisters
Take Victoria Line to Victoria
Take Circle Line to Victoria
Take District Line to Mile End
Take District Line to Embankment
Take Northern Line to Kennington
Take Northern Line to Bank
Take Circle Line to Bank
Take Central Line to Mile End
Take District Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Liverpool Street
Take Circle Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Aldgate
Take Metropolitan Line to Croxley
Take Metropolitan Line to Aldgate
Take Circle Line to Aldgate
Take Circle Line to Bank
Take Circle Line to Bank
Take District Line to Gunnersbury
Take District Line to Upminster
Take District Line to Gunnersbury
Take District Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Hammersmith
Take District Line to Gunnersbury
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Gunnersbury
Take District Line to West Brompton
Take District Line to Gunnersbury
Take District Line to Mile End
Take District Line to Acton Town
Take District Line to Mile End
Take District Line to Paddington
Take Circle Line to Paddington
Take Circle Line to Victoria
Take Victoria Line to Seven Sisters
Take Victoria Line to Victoria
Take Circle Line to Victoria
Take District Line to Mile End
Take District Line to Acton Town
Take District Line to Acton Town
Take Piccadilly Line to Hounslow Central
Take Piccadilly Line to Acton Town
Take District Line to Acton Town
Take District Line to Mile End
Take District Line to Gunnersbury
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Gunnersbury
Take District Line to Paddington
Take Circle Line to Bank
Take Circle Line to Bank
Take Northern Line to Mornington Crescent



Try it online! 


Explanation


First, a quick refresher on Mornington Crescent:


    

  • each station can either hold a string of arbitrary length or a bigint
    • 

  • there's also an accumulator which also holds a string or a bigint
    • 

  • all stations start with their own name as their value
    • 

  • at the beginning, the accumulator contains your program's input
    • 

  • each time you go to a station, the station's value and the accumulator are swapped
    • 

  • some stations are special and override this behavior
    • 

  • the line you use to get to a station doesn't matter
    • 

  • you start at Mornington Crescent
    • 

  • to end the program, you go to Mornington Crescent too
    • 

  • at the end, the value of the accumulator is printed
    • 



Since printing strings is hard (see Martin Ender's Mornington Crescent "Hello, World!" program), we will need a simple template that can be used to output generic strings. Since the length of the generated programs don't matter, I've settled on this:


Take Northern Line to Bank
Take Northern Line to Bank
Take District Line to Paddington



We'll need to generate each character separately and concatenate them, since the substring approach used by Martin is much harder to implement in the general case. Paddington is the station that performs string concatenation. When you arrive at Paddington, the following happens:


accumulator, paddington = paddington + accumulator, accumulator



This behavior is used to initialize Paddington to the empty string that's assumed to be the input.


Take District Line to Victoria
Take Victoria Line to Seven Sisters
Take Victoria Line to Euston
Take Victoria Line to Euston
Take Northern Line to Bank



Go to Seven Sisters, which sets the accumulator to 7, and store it in the Bank. The Bank is the only way to copy values - Hammersmith is a readonly copy of Bank's value.


Take District Line to Hammersmith
Take District Line to Cannon Street
Take District Line to Hammersmith
Take District Line to Cannon Street
Take District Line to Bank



Divide 7 by 7 to get 1, a divisor of all ASCII values we need to support.


Take District Line to Hammersmith
Take District Line to Upminster



For each character, start by copying the 1 to Upminster.


Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster
Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Upminster



Add more ones as necessary.


Take District Line to Hammersmith
Take District Line to Upminster
Take District Line to Bank
Take District Line to Bank
Take Northern Line to Charing Cross
Take Northern Line to Charing Cross
Take Bakerloo Line to Paddington
Take Bakerloo Line to Paddington
Take Bakerloo Line to Charing Cross
Take Northern Line to Embankment



Finish up by going to Upminster only once, to keep the new value in the accumulator instead of storing it again. Take it to Charing Cross to turn the ASCII value into a character and append it to the string. The last two lines are there because I've misread the specification, so I'll stop here and golf my program down first.

 

 

 

 
 
 

 

 

 

 answered Apr 7, 2018 at 13:07
 

 
 

 
 


 

 

 
 
 

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 (disclaimer: I've just learnt this language) About the exact same approach I can think of (7/7=1). But why don't you just set Upminister only once at the beginning of the program?
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 @user202729 How would that work? / Fun fact: repeated Take District Line to Upminster lines calculate the fibonacci sequence 
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 Looks like I misunderstood the spec. But that's exactly what it says there... someone need to edit the wiki.
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Jelly, 1 byte


Ṿ



Woo builtins!


The builtin Ṿ unevals the input.


Try it online! 


A more interesting one:


)""j



Joins the string """" by the input.


Try it online! 

 

 

 

 
 
 

 

 

 

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 For the second one I think you can do ""; for -1.
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Charcoal, 1 byte


θ



By default, a string of ASCII characters .. ~ simply prints itself, so it just remains to print the input.

 

 

 

 
 
 

 

 

 

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 I was going to add this same answer. :-)
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 @CarlosAlejo Well it's not as if there was a different answer...
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 Well there is :P
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 @ASCII-only Touché!
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C (gcc), (削除) 89 (削除ここまで) (削除) 87 (削除ここまで) (削除) 58 (削除ここまで) 56 bytes


Saved two bytes thanks to Jakob!


main(a,c)char**c;{printf("main(){puts(\"%s\");}",c[1]);}



Try it online! 

 

 

 

 
 
 
 

 

 

 

 answered Aug 13, 2017 at 20:24
 

 
 

 
 


 

 

 
 
 

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 "It must be able to handle any combination of characters A-Z, a-z, and 0-9." You might want to go with the escapes strategy after all.
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 @Jakob yeah I just read that :/, thanks
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 I had also just finished writing the escaper regex for a Java solution when I read that. Bummer.
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 @Jakob Yeah, same for me, but with eacal. RIP
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 You can use puts in the printed program to save 2 bytes, right? Or is it a problem that it appends a newline?
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Japt, 2 bytes


iQ



Try it online! 


i is a function that inserts a specified string at a specified index into the input. Q is a variable that defaults to a quotation mark ", and since there's no index given, this defaults to 0. The end result is a quotation mark inserted at the beginning of the string, which Japt auto-finishes when running.


This works on strings containing anything except ", {, or \, though of course the string is guaranteed to consist of alphanumeric chars so this doesn't matter.

 

 

 

 
 
 

 

 

 

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Python 2, 22 bytes


print'print%r'%input()



Try it online! 

 

 

 

 
 
 

 

 

 

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 An alternate 22 byte solution is print'print'+`input()`.
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 This wouldn't work. input in Python 2 is equivalent to eval(raw_input()). So it has to be a pythonic expression for it to work.
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 Yes, that is allowed. ---Let me find the appropriate meta...--- Aha, found it. 
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MATLAB / Octave, 15 bytes


@(t)['disp ',t]



Try it online! 


I completely overlooked the fact that the program only needs to handle alphanumeric characters, or, importantly, does not need to handle space characters. This means we can use the 'command' syntax, which uses significantly less bytes.


MATLAB, 27 bytes


For completeness, here's a version that can handle arbitrary input:


@(t)['disp(',mat2str(t),41]



Defines an anonymous function taking the string t, and converts it to the program. Curiously, this does not work in Octave, which seems to have different ideas of what mat2str should do.

 

 

 

 
 
 
 

 

 

 

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 I can't test this, but I think: @(t)['disp ',mat2str(t)] should work...?
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 Apr 7, 2018 at 13:43
 
 
    
 
    
 
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 @StewieGriffin That doesn't work because mat2str adds quotation marks, which are not necessary in command syntax. I had the function syntax combined with mat2str to handle spaces in the input, but on rereading the challenge, that's not actually necessary, cutting the bytecount nearly in half. Thanks!
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 I thought quotation marks was necessary if there were spaces in the input but I might be wrong. I didn't notice that the input was only alphanumeric either...
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 Like this (ungolfed).
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 @StewieGriffin You are right, I misjudged the way command syntax works. However, command syntax seems to be full of suprises: Try it online! 
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PowerShell, 9 Bytes


"'$args'"



single or double quotes in powershell can be used to contain strings, but only double-quotes allow variable expansion.


with an input of foo this will output 'foo' which is a valid powershell program which outputs foo

 

 

 

 
 
 
 

 

 

 

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Befunge-98 (FBBI), (削除) 21 (削除ここまで) (削除) 16 (削除ここまで) 12 bytes


-5 bytes thanks to NieDzejkob 

-4 bytes thanks to Jo King 


#,~'',,',,'@



Try it online! 


Outputs 't,'e,'s,'t,@ for an input of test


How?


Initially the pointer moves East:


#, # skips the next instruction
 ~ push a byte of input
 '', push ' and print it
 , print the byte of input
 ',, push , and print it 
 '@ push @ to the stack



If there is no more input left, ~ reverses the direction of the pointer:


 , print @
# skip nothing
 @ terminate


 

 

 

 
 
 
 

 

 

 

 answered Apr 7, 2018 at 14:47
 

 
 

 
 


 

 

 
 
 

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Emojicode, 88 bytes


🐖😍➡️🔡🍇🍎🍪🔤🏁🍇😀❌🔤🔤🐕🔤❌🔤🍉🔤🍪🍉



Try it online! 


Input:


anyString



Output:


🏁🍇😀🔤anyString🔤🍉



Script Output:


anyString


 

 

 

 
 
 

 

 

 

 answered Apr 9, 2018 at 18:21
 

 
 

 
 


 

 

 
 
 

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QBIC, 7 bytes


?@?@`+;



Explanation


? PRINT on the screen
 @ ` a literal
 ?@ question mark and at
 +; and append the input



Sample run


Command line: lala
?@lala



The output is a string literal containing the input, preceded with a PRINT command.

 

 

 

 
 
 

 

 

 

 answered Aug 13, 2017 at 19:47
 

 
 

 
 


 

 

 
 
 

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Batch 11 bytes


I'm sure there's away to get it smaller, but this is pretty small.


set/p=echo 



The breakdown:


set ::Define new variable
 /p ::Create prompt
 = ::Define a variable in prompt
 echo ::Prompt begins with 'echo '



In English:


The user is asked for input with a leading phrase echo. Then the user may type in whatever, and the program terminates (e.g; echo hello world!). This leaves us with a program that when ran, will output hello world!.


Yes, the whitespace is supposed to be there

 

 

 

 
 
 

 

 

 

 answered Aug 13, 2017 at 22:03
 

 
 

 
 


 

 

 
 
 

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 I don't know batch (and this is from long ago), but this looks wrong. Wouldn't the echo portion be text echoed to the console and not program output?
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 Jun 19, 2018 at 4:13
 
 
    
 
    
 
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 @Jakob suprosingly no, it's essentially functionally equivalent to the python example given in the initial challenge.
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 Commented
 Jun 19, 2018 at 4:19
 
 
    
 
    
 
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 Oops--what I meant is that I doubt the program outputs the text the user types. It's probably just echoed to the console, right?
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 Jun 19, 2018 at 4:30
 
 
    
 
    
 
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 @Jakob Right, which is equivalent to printing. The example prints a print function while mine echos an echo function.
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 Jun 19, 2018 at 4:36
 
 
    
 
    
 
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 OK, but the example prints the entire program to standard out. Your program prints only echo  to standard out. In fact, (I assume) if input comes from a file or pipe, all you'd see is the prompt. Has that kind of output been allowed?
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V, 2 bytes


ii



In Vim, i changes to insert mode and allows inserting text. In this case, it just inserts the i in front of the input text (to create the second program). V is Vim compatible, but adds an implicit <esc> to the end of the program, so I don't need to worry about it here.

 

 

 

 
 
 
 

 

 

 

 answered Aug 14, 2017 at 11:43
 

 
 

 
 


 

 

 
 
 

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Cubically, 87 bytes


U3D1R3L1F3B1U1D3~:7+1(-1@3(-1%1)6:1+3111@6%1-31111+004@6:1+11111%6:1+45@6:1-1%6~:7+1)6 



Try it online! 


A port of my answer here. There already existed a challenge to take input and output Cubically code that produced that input, and I had an answer in Cubically so... profit?

 

 

 

 
 
 

 

 

 

 answered Aug 14, 2017 at 15:07
 

 
 

 
 


 

 

 
 
 

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 Save a few bytes - remove the arguments from %6s and @6s; they can now be called implicitly. (You can also do that on your answer on the cubifier thread.)
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D, (削除) 92 (削除ここまで) 89 bytes


void main(){import std.stdio;write(`void main(){import std.stdio;"`~readln~`".write;}`);}



Try it online! 

 

 

 

 
 
 
 

 

 

 

 answered Aug 14, 2017 at 11:19
 

 
 

 
 


 

 

 
 
 

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SmileBASIC, 21 bytes


Maybe this is cheating...


LINPUT"?"+CHR$(34);S$



Asks for input with the prompt ?". (? is short for PRINT, and closing quotes are not required). So the "output" program is ?"<text>

 

 

 

 
 
 
 

 

 

 

 answered Mar 21, 2018 at 16:40
 

 
 

 
 


 

 

 
 
 

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Python 2, 17 bytes


'print%r'.__mod__



Try it online! 

 

 

 

 
 
 

 

 

 

 answered Apr 7, 2018 at 14:16
 

 
 

 
 


 

 

 
 
 

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 This fails for 1
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 Commented
 Apr 7, 2018 at 18:36
 
 
    
 
    
 
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 @NoOneIsHere the challenge requires to take a string as input. If you pass '1' to the function it correctly outputs print'1'
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 Oh, I'm sorry. I didn't notice that.
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SOGL V0.12, 2 bytes 


$+



Try it Here! (expects input on stack so , is added for ease-of-use)


$ pushes ", + joins that after the input on the stack.

 

 

 

 
 
 
 

 

 

 

 answered Aug 13, 2017 at 19:48
 

 
 

 
 


 

 

 
 
 

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 You can use `"` for ".
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 Aug 13, 2017 at 19:49
 
 
    
 
    
 
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 @NoOneIsHere yeah, that makes sense.. Used it everywhere else except where it's the most useful .-.
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Perl 6, 19 bytes


say "say "~get.perl



Try it 


This should work for any Unicode input in NFC

 

 

 

 
 
 

 

 

 

 answered Aug 13, 2017 at 19:51
 

 
 

 
 


 

 

 
 
 

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 Can you remove the space?
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 Commented
 Aug 13, 2017 at 19:52
 
 
    
 
    
 
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 @NoOneIsHere Removing either space would result in a two terms in a row error. Perl 6 has significant whitespace, but it is only significant in that it either has to be there, or has to not be there. (there are ways of opting out of both though)
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8th, (削除) 34 (削除ここまで) 37 bytes


Code


: f >s "\"" tuck s:+ s:+ " ." s:+ . ;



Example


ok> "Print 42" f
"Print 42" .
ok> "Print 42" .
Print 42


 

 

 

 
 
 
 

 

 

 

 answered Aug 13, 2017 at 20:05
 

 
 

 
 


 

 

 
 
 

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PHP, 12 bytes


<?=$argv[1];



Try it online! 


This is to be run from the command line with the input as the parameter argument. And yes, it simply outputs the input string—but that is valid PHP: anything outside the <?php ?> delimiters is output unprocessed.


Here is the script produced by the 'testing123' input in action as a demonstration: Try it online! 

 

 

 

 
 
 

 

 

 

 answered Aug 13, 2017 at 20:33
 

 
 

 
 


 

 

 
 
 

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 this won't work quite right if the input string contains <?php, mind you ;)
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 Commented
 Aug 14, 2017 at 20:06
 
 
    
 
    
 
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 @Andrea Read the question: "It must be able to handle any combination of characters A-Z, a-z, and 0-9." So '<?php' is invalid input...
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 Aug 15, 2017 at 6:22
 
 
    
 
    
 
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 aw, that's too easy :(
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 Commented
 Aug 15, 2017 at 21:33
 
 
    
 
    
 
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MATL, 2 bytes


&D



Try it online! 


Simply wraps the string in quotes using &D, which is MATL's equivalent to MATLAB's mat2str, a function specifically made to make something that, when eval'd, will give the original matrix (or in this case, string).


The resulting 'program' is just the input string wrapped in quotes, which is thus pushed on the stack, and implicitly displayed.

 

 

 

 
 
 

 

 

 

 answered Aug 13, 2017 at 20:51
 

 
 

 
 


 

 

 
 
 

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eacal, 38 bytes


strap string put string 
put strap arg



Try it online! 


Simply appends the string put string to the memory string, then appends the argument, which is printed.

 

 

 

 
 
 

 

 

 

 answered Aug 13, 2017 at 21:13
 

 
 

 
 


 

 

 
 
 

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Batch, 14 bytes


@echo @echo(%*



Works for special characters too if they are quoted using "s rather than ^.

 

 

 

 
 
 
 

 

 

 

 answered Aug 13, 2017 at 21:12
 

 
 

 
 


 

 

 
 
 

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 Perhaps @echo.@echo.%* would be more correct? The input could be potentially empty.
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 Commented
 Aug 13, 2017 at 21:14
 
 
    
 
    
 
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 @ConorO'Brien Well I don't need the first . because that's never empty, and I used a ( for the second case because that's more reliable than ., but thanks for the suggestions anyway!
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 Commented
 Aug 13, 2017 at 21:22
 
 
    
 
    
 
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 np! I just like the symmetry between the @echo.s lol
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 Commented
 Aug 13, 2017 at 21:23
 
 
    
 
    
 
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Ly, 14 bytes


"\""&i"\"&o"&o



Try it online! 


Explanation


"\""&i"\"&o"&o
"\"" # push `"`
 &i # take input
 "\"&o" # push `"&o`
 &o # output stack
 # test -> "test"&o
 # "test"&o = push "test" and output stack


 

 

 

 
 
 

 

 

 

 answered Aug 13, 2017 at 21:55
 

 
 

 
 


 

 

 
 
 

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JavaScript ES6, 25 bytes (outputs code to "standard output")


s=>alert(`alert('${s}')`)



JavaScript ES6, 23 bytes (returns code, that outputs to "standard output")


s=>`alert('${s}')`



JavaScript ES6, 14 bytes (returns a function, that returns the result)


s=>`_=>"${s}"`


 

 

 

 
 
 
 

 

 

 

 answered Aug 13, 2017 at 20:50
 

 
 

 
 


 

 

 
 
 

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 You're missing the quotation marks in your last solution, which should be your submitted solution as it's the shortest of the 3.
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 Commented
 Aug 13, 2017 at 20:58
 
 
    
 
    
 
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 @Shaggy Right, let me add i
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 Commented
 Aug 13, 2017 at 20:59
 
 
    
 
    
 
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 You swapped string literals in your last function (and now it throws syntax error). Side note: it is not returning a function, it is returning a string which represents a function which returns the input.
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 Commented
 Aug 13, 2017 at 21:31
 
 
    
 
    
 
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Brain-Flak, (削除) 92 (削除ここまで) 68 bytes


-22 bytes thanks to Wheat Wizard 


Includes +2 for -cr


{<>(((((()()()()()){}){}){})())<>{({}[()])<>((({}[()])()))<>}{}}<>



Try it online! 


# For every character
{
 # Put ")(" on the off stack
 <>(((((()()()()()){}){}){})())<>
 # for 0 to the ASCII value of this character
 {({}[()])
 # Replace the ")" with "(" and add "))"
 <>((({}[()])()))<>
 # End for
 }{}
# end for and switch to the off stack for printing (in reverse order because of -r)
}<>


 

 

 

 
 
 
 

 

 

 

 answered Aug 14, 2017 at 13:49
 

 
 

 
 


 

 

 
 
 

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Pyth, (削除) 2 (削除ここまで) 1 byte


z



Try it online! 


Just outputs the input. Requires strings to be in quotes.


-1 byte thanks to KarlKastor

 

 

 

 
 
 
 

 

 

 

 answered Aug 13, 2017 at 19:45
 

 
 

 
 


 

 

 
 
 

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 Can you just do +\"? (\x char literal + implicit Q)
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 Commented
 Aug 13, 2017 at 19:46
 
 
 
 
 
    
 
    
 
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 @ETHproductions Even better, +N
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 Commented
 Aug 13, 2017 at 19:47
 
 
    
 
    
 
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 Nice, I don't know Pyth quite that well :-)
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 Commented
 Aug 13, 2017 at 19:47
 
 
 
 
 
    
 
    
 
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