Reverse stdin and place on stdout

Question

Requirements:

• Take an input on stdin including new lines / carriage returns of unlimited length (only bounded by system memory; that is, there is no inherent limit in the program.)
• Output the reverse of the input on stdout.

Example:

Input:

Quick brown fox
He jumped over the lazy dog

Output:

god yzal eht revo depmuj eH
xof nworb kciuQ

Shortest wins.

Answer 1

Golfscript - 3 chars

-1%

obfuscated version is also 3 chars

0(%

here is an explanation of how % works

Answer 2

Bash - 7

tac|rev

tac reverses line order, while rev reverses character order.

Answer 3

Haskell - 21

main=interact reverse

Answer 4

Here's my entry, Python, 41 40 chars:

import sys;print sys.stdin.read()[::-1]

41 -> 40 - removed semicolon at end of program.

Probably could be optimised!

Answer 5

C-37 bytes

main(_){write(read(0,&_,1)&&main());}

Answer 6

Perl - 23

print scalar reverse <>

Answer 7

BrainFuck, 10 characters

,[>,]<[.<]

Beats a good amount of answers for such a simple language.

Answer 8

Windows PowerShell, 53 54

-join($x=[char[]]($($input)-join'
'))[($x.count)..0]

2011-01-30 (54) – First attempt

2011-01-30 (53) – Inline line breaks are fun.

2011-01-3- (52) – Inlined variable assignments too.

Answer 9

Ruby - 19 characters

puts$<.read.reverse

Answer 10

Befunge-93 - 11x2 (22 characters)

>~:0`v >:v
^    _$^,_@

Tested using this interperter.

Answer 11

C - 47 characters

main(c){if(c=getchar(),c>=0)main(),putchar(c);}

Note that this uses O(n) stack space.

Answer 12

Python - 35 chars

import os;print os.read(0,2e9)[::-1]

Answer 13

C++ - 168 chars

#include<algorithm>
#include<iostream>
#include<string>
using namespace std;main(){string m;for(string l;getline(cin,l);)m+=l+"\n";reverse(m.begin(),m.end());cout<<m;}

Answer 14

Perl

print scalar reverse for reverse(<STDIN>);

Answer 15

PHP - 38 17 characters

<?=strrev(`cat`);

Answer 16

PHP, 82 29 24 29 28 characters

<?=strrev(fread(STDIN,2e9));

82 -> 29: The new line character is preserved when reversed with strrev.
29 -> 24: Uses the shortcut syntax now
24 -> 29: Now reads all lines instead of a single line

Answer 17

Groovy 44 characters

args.reverse().each{print it.reverse()+" "}

Answer 18

PHP - 44 characters

<?=strrev(file_get_contents('php://stdin'));

Answer 19

C# - 116

using System.Linq;using c=System.Console;class p{static void Main(){c.Write(c.In.ReadToEnd().Reverse().ToArray());}}

Answer 20

VB.Net - 96

Module M
Sub Main()
Console.Write(CStr(ConsoleIn.ReadToEnd.Reverse.ToArray))
End Sub
End Module

90 (With Turned off Option Strict)

Module M
Sub Main()
Console.Write(Console.In.ReadToEnd.Reverse.ToArray)
End Sub
End Module