{{task}} Quoting from the [http://esolangs.org/wiki/Narcissist Esolangs wiki page]:

A '''narcissist''' (or '''Narcissus program''') is the decision-problem version of a [[quine]].

A quine, when run, takes no input, but produces a copy of its own source code at its output. In contrast, a narcissist reads a string of symbols from its input, and produces no output except a "1" or "accept" if that string matches its own source code, or a "0" or "reject" if it does not.

For concreteness, in this task we shall assume that symbol = character.

The narcissist should be able to cope with any finite input, whatever its length.

Any form of output is allowed, as long as the program always halts, and "accept", "reject" and "not yet finished" are distinguishable.

Ada

{{works with|Ada 2005}}

Took code from [[Quine]], has to be in one line (could be done pretty printed, too, but not as simple).

with Ada.Text_IO;procedure Self is Q:Character:='"';A:String:="with Ada.Text_IO;procedure Self is Q:Character:='';A:String:=;B:String:=A(1..49)&Q&A(50..61)&Q&A&Q&A(62..A'Last);C:String:=Ada.Text_IO.Get_Line;begin Ada.Text_IO.Put_Line(Boolean'Image(B=C));end Self;";B:String:=A(1..49)&Q&A(50..61)&Q&A&Q&A(62..A'Last);C:String:=Ada.Text_IO.Get_Line;begin Ada.Text_IO.Put_Line(Boolean'Image(B=C));end Self;

ALGOL 68

{{works with|ALGOL 68|Revision 1 - no extensions to language used}}

{{works with|ALGOL 68G|Any - tested with release [http://sourceforge.net/projects/algol68/files/algol68g/algol68g-1.18.0/algol68g-1.18.0-9h.tiny.el5.centos.fc11.i386.rpm/download 1.18.0-9h.tiny]}} {{wont work with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release [http://sourceforge.net/projects/algol68/files/algol68toc/algol68toc-1.8.8d/algol68toc-1.8-8d.fc9.i386.rpm/download 1.8-8d] - due to extensive use of '''format'''[ted] ''transput''}}

STRINGs="STRINGs="";print(readstring=2*s[:9]+2*s[9:])";print(readstring=2*s[:9]+2*s[9:])

Output: T or F depending on input.

AutoHotkey

{{works with|AutoHotkey 1.1}}

Narcissist(Input) {
	FileRead, Source, % A_ScriptFullPath
	return Input == Source ? "accept" : "reject"
}

'''Example Use:'''

MsgBox, % Narcissist(FileOpen(A_ScriptFullPath, "r").Read()) "`n"
	. Narcissist("This isn't the text you're looking for.")

{{Output}}

accept
reject

BBC BASIC

{{works with|BBC BASIC for Windows}} Prints '1' on success and '0' on failure.

INPUT a$:PRINT -(a$=$(PAGE+34)+$(PAGE+33)):REM INPUT a$:PRINT -(a$=$(PAGE+34)+$(PAGE+33)):REM

Befunge

Reads from stdin up to the first carriage return, line feed, or EOF. However, the latter is not guaranteed to work on all Befunge implementations - in particular not on Befunge-98 - so a line break is recommended.

Outputs 1 if the given line of input matches the source code, and 0 if it doesn't.

900:0g~>:::0>`#0\#:5#:5#:+#<#~-#g*#0\#:5#+8#1+#\-#!*#-_$$"E"-!>_9-!.@

C

Based upon the quine. Reads until EOF or newline from stdin, and writes "1" or "0" to stdout.

extern void*stdin;main(){ char*p = "extern void*stdin;main(){ char*p = %c%s%c,a[300],b[300];sprintf(a,p,34,p,34);fgets(b,300,stdin);putchar(48+!strcmp(a,b)); }",a[300],b[300];sprintf(a,p,34,p,34);fgets(b,300,stdin);putchar(48+!strcmp(a,b)); }

C#

using System;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;
namespace Narcisisst
{
	class Program
	{
		public static void Main(string[] args)
		{
			const string path = @"E:\Narcisisst";
			string[] thisFile = Directory.GetFiles(path , "Program.cs");
			StringBuilder sb = new StringBuilder();

				foreach (string readLine in File.ReadLines(thisFile[0]))
				{
					sb.Append(readLine);
					sb.Append("\n");
				}

			Console.WriteLine(sb);
			string input =String.Empty;
			       	input = Console.ReadLine();
			       	Console.WriteLine((Regex.IsMatch(sb.ToString(),input))?"accept":"reject");
			       	Console.ReadKey();
			 }
	}
}

Common Lisp

Only checks the first line of stdin:

#1=(PRINT (EQUAL (WRITE-TO-STRING '#1# :CIRCLE 1) (READ-LINE *STANDARD-INPUT*)))

D

import std.file; import std.stdio; import std.string; void main() { auto source = readText("narcissist.d").chomp; auto input = readln().chomp(); if (source == input) writeln("accept"); else writeln("reject"); }

=={{header|Déjà Vu}}==

!. = !prompt "Enter my code: " concat( swap !decode!utf-8 !encode!quoted dup swap ) "!. = !prompt \qEnter my code: \q concat( swap !decode!utf-8 !encode!quoted dup swap ) "

Forth

: narcissist  [ source ] sliteral compare 0= ;

Go

This version reads until EOF and expects a newline at the end of the input. If this is being checked from a file, make sure that the file has exactly one newline at the end of it.

package main; import "os"; import "fmt"; import "bytes"; import "io/ioutil"; func main() {ios := "os"; ifmt := "fmt"; ibytes := "bytes"; iioutil := "io/ioutil"; zero := "Reject"; one := "Accept"; x := "package main; import %q; import %q; import %q; import %q; func main() {ios := %q; ifmt := %q; ibytes := %q; iioutil := %q; zero := %q; one := %q; x := %q; s := fmt.Sprintf(x, ios, ifmt, ibytes, iioutil, ios, ifmt, ibytes, iioutil, zero, one, x); in, _ := ioutil.ReadAll(os.Stdin); if bytes.Equal(in, []byte(s)) {fmt.Println(one);} else {fmt.Println(zero);};}\n"; s := fmt.Sprintf(x, ios, ifmt, ibytes, iioutil, ios, ifmt, ibytes, iioutil, zero, one, x); in, _ := ioutil.ReadAll(os.Stdin); if bytes.Equal(in, []byte(s)) {fmt.Println(one);} else {fmt.Println(zero);};}

A version respecting the 80 character line limit:

package main

import (
    "bytes"
    "fmt"
    "io/ioutil"
    "os"
)

func main() {
    s := fmt.Sprintf("%s%c%s%c\n", x, 0x60, x, 0x60)
    in, _ := ioutil.ReadAll(os.Stdin)
    if bytes.Equal(in, []byte(s)) {
        fmt.Println("Accept")
    } else {
        fmt.Println("Reject")
    }
}

var x = `package main

import (
    "bytes"
    "fmt"
    "io/ioutil"
    "os"
)

func main() {
    s := fmt.Sprintf("%s%c%s%c\n", x, 0x60, x, 0x60)
    in, _ := ioutil.ReadAll(os.Stdin)
    if bytes.Equal(in, []byte(s)) {
        fmt.Println("Accept")
    } else {
        fmt.Println("Reject")
    }
}

var x = `

Haskell

main = let fi t e c = if c then t else e in do ct <- getContents; putStrLn $ fi ['a','c','c','e','p','t'] ['r','e','j','e','c','t'] $ take (length ct - 1) ct == let q s = (s ++ show s) in q "main = let fi t e c = if c then t else e in do ct <- getContents; putStrLn $ fi ['a','c','c','e','p','t'] ['r','e','j','e','c','t'] $ take (length ct - 1) ct == let q s = (s ++ show s) in q "

Huginn

#! /bin/sh
exec huginn --no-argv -E "${0}"
#! huginn

main() {
	c = "#! /bin/sh{1}~"
		"exec huginn --no-argv -E {3}${{0}}{3}{1}#! huginn{1}{1}~"
		"main() {{{1}{2}c = {3}{0}{3};{1}~"
		"{2}s = {3}{3};{1}~"
		"{2}while ( ( line = input() ) != none ) {{{1}~"
		"{2}{2}s += line;{1}~"
		"{2}}}{1}~"
		"{2}self = copy( c ).replace( {3}{5}{3}, {3}{3} )~"
		".format({1}{2}{2}c.replace( {3}{5}{3}, ~"
		"{3}{5}{4}{3}{4}n{4}t{4}t{4}{3}{3} ), ~"
		"{3}{4}n{3}, {3}{4}t{3}, {3}{4}{3}{3}, {3}{4}{4}{3}, ~"
		"{3}{5}{3}{1}{2});{1}~"
		"{2}print( s == self ? {3}1{4}n{3} : {3}0{4}n{3} );{1}}}{1}{1}";
	s = "";
	while ( ( line = input() ) != none ) {
		s += line;
	}
	self = copy( c ).replace( "~", "" ).format(
		c.replace( "~", "~\"\n\t\t\"" ), "\n", "\t", "\"", "\\", "~"
	);
	print( s == self ? "1\n" : "0\n" );
}

=={{header|Icon}} and {{header|Unicon}}== {{trans|Go}} Since we can't put a link statement and program on a single line, we implement a simplified inline sprintf so we don't have to deal with all the double quotes or substrings and offsets. If we'd needed to write multiple procedures on a line it can be done [[Icon%2BUnicon/Intro#Semi-colons| Semi-colons in the language intro]]

procedure main();yes:="Accept";no:="Reject";pat:="procedure main();yes:=$;no:=$;pat:=$;a:=[yes,no,pat];narc:=char(0)[0:0];pat?{while narc||:=tab(find(char(36))) do{narc||:=image(get(a));move(1)};narc||:=tab(0)};write(if read()==narc then yes else no);end";a:=[yes,no,pat];narc:=char(0)[0:0];pat?{while narc||:=tab(find(char(36))) do{narc||:=image(get(a));move(1)};narc||:=tab(0)};write(if read()==narc then yes else no);end

Example:

./narcissist.exe < narcissist.icn
Accept

Actually, this version recognizes all files where the first line is the Narcissist.

J

#!/j602/bin/jconsole
main=:3 : 0
  self=: '#!/j602/bin/jconsole',LF,'main=:',(5!:5<'main'),LF,'main''''',LF
  echo  self -: stdin''
)
main''

Example use:

$ ./narcissist.ijs <narcissist.ijs 1

Note that this assumes a suitable os command line.


'''Alternative solution:'''

```j
   narcissist=.(-:,~,2#{:)&'(-:,~,2#{:)&'''

'''Example use:'''

   (-:,~,2#{:)&'(-:,~,2#{:)&''' '(-:,~,2#{:)'
0
   (-:,~,2#{:)&'(-:,~,2#{:)&''' '(-:,~,2#{:)&''(-:,~,2#{:)&'''''''
1

Java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Narcissist {
    private static final String SOURCE = "import java.io.BufferedReader;%nimport java.io.IOException;%nimport java.io.InputStreamReader;%n%npublic class Narcissist {%n    private static final String SOURCE = %c%s%c;%n    private static final char QUOTE = 0x22;%n%n    public static void main(String[] args) throws IOException {%n        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));%n        StringBuilder sb = new StringBuilder();%n%n        while (true) {%n            String line = br.readLine();%n            if (null == line) break;%n            sb.append(line).append(System.lineSeparator());%n        }%n%n        String program = String.format(SOURCE, QUOTE, SOURCE, QUOTE, QUOTE, QUOTE, QUOTE, QUOTE);%n        if (program.equals(sb.toString())) {%n            System.out.println(%caccept%c);%n        } else {%n            System.out.println(%creject%c);%n        }%n    }%n}%n";
    private static final char QUOTE = 0x22;

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();

        while (true) {
            String line = br.readLine();
            if (null == line) break;
            sb.append(line).append(System.lineSeparator());
        }

        String program = String.format(SOURCE, QUOTE, SOURCE, QUOTE, QUOTE, QUOTE, QUOTE, QUOTE);
        if (program.equals(sb.toString())) {
            System.out.println("accept");
        } else {
            System.out.println("reject");
        }
    }
}

JavaScript

{{works with|SpiderMonkey|1.7.0}} Based upon [[Quine#Using_eval|one of the quines]]. Outputs 'true' if source is equal to inputted line (newline terminated), 'false' otherwise.

var code='var q=String.fromCharCode(39);print("var code=" + q + code + q + "; eval(code)" == readline())'; eval(code)

{{works with|JScript}}

var oFSO = new ActiveXObject("Scripting.FileSystemObject");
function readfile(fname) {
	var h = oFSO.OpenTextFile(fname, 1, false);
	var result = h.ReadAll();
	h.Close();
	return result;
}

if (0 === WScript.Arguments.UnNamed.Count) {
	WScript.Echo(WScript.ScriptName,"filename");
	WScript.Quit();
}

// first read self
var self = readfile(WScript.ScriptFullName);
// read whatever file is given on commmand line
var whatever = readfile(WScript.Arguments.UnNamed(0));

// compare and contrast
WScript.Echo(self === whatever ? "Accept" : "Reject");

{{works with|Julia|1.2}}

Julia

mysource = Base.read(Base.source_path(), String)
println(Int(ARGS[1] == mysource))

Kotlin

// version 1.1.0 (run on Windows 10)

fun main(args: Array<String>) {
    val text = java.io.File("narcissist.kt").readText()
    println("Enter the number of lines to be input followed by those lines:\n")
    val n = readLine()!!.toInt()
    val lines = Array<String>(n) { readLine()!! }
    if (lines.joinToString("\r\n") == text) println("\naccept") else println("\nreject")
}

First run (pasting in program text): {{out}}

Enter the number of lines to be input followed by those lines:

9
// version 1.1.0 (run on Windows 10)

fun main(args: Array<String>) {
    val text = java.io.File("narcissist.kt").readText()
    println("Enter the number of lines to be input followed by those lines:\n")
    val n = readLine()!!.toInt()
    val lines = Array<String>(n) { readLine()!! }
    if (lines.joinToString("\r\n") == text) println("\naccept") else println("\nreject")
}

accept

Second run (entering any old rubbish):

{{out}}

Enter the number of lines to be input followed by those lines:

1
the quick brown fox

reject

Liberty BASIC

NOTE: You have to manually type in ALL of the code since the Input statement will not successfully input data from a paste event even though it will show up in the MainWin.

 s$ = "s$ = Input a$ : Print (a$ = Left$(s$, 5) + chr$(34) + s$ + chr$(34) + Mid$(s$, 14, 3) + Mid$(s$, 6, 100)) + Mid$(s$, 23, 3)" : Input a$ : Print (a$ = Left$(s$, 5) + chr$(34) + s$ + chr$(34) + Mid$(s$, 14, 3) + Mid$(s$, 6, 100))

Mathematica

{{in}}

prog = "prog = ``;\nPrint[InputString[] == \n   ToString[StringForm[prog, ToString[prog, InputForm]]]];";
Print[InputString[] ==
   ToString[StringForm[prog, ToString[prog, InputForm]]]];

{{out}}

True

PARI/GP

narcissist()=input()==narcissist

Run narcissist():

Hello
0

narcissist() = {input() == narcissist;}
1

Perl

# this is file narc.pl
local $/;
print do { open 0; <0> } eq <> ? "accept" : "reject";

Run: perl narc.pl < narc.pl

## Perl 6


For the narcissist to work you must be very careful with whitespace. The following version works if it is given to standard input as exactly one line terminated by a newline character.

Note how the code takes advantage of Perl 6's ability to nest quoting delimiters.


```perl6
EVAL my $self = q{say slurp() eq q[EVAL my $self = q{]~$self~q[}]~10.chr ?? q{Beautiful!} !! q{Not my type.}}

{{out}}

$ narcissist='EVAL my $self = q{say slurp() eq q[EVAL my $self = q{]~$self~q[}]~10.chr ?? q{Beautiful!} !! q{Not my type.}}'
$ perl6 -e "$narcissist" <<<"$narcissist"
Beautiful!
$ perl6 -e "$narcissist" <<<"$narcissist # a comment ruining it all"
Not my type.

Phix

puts(1,{"\n\ntrue\n\n","\n\nfalse\n\n"}[1+(gets(open(command_line()[2],"r"))!=gets(0))])

PicoLisp

(de narcissist (Str)
   (= Str (str narcissist)) )

Output:

: (narcissist "(Str) (= Str (str narcissist))")
-> T

PowerShell

{{works with|PowerShell|2}}

function Narcissist
{
Param ( [string]$String )
If ( $String -eq $MyInvocation.MyCommand.Definition ) { 'Accept' }
Else { 'Reject' }
}

Narcissist 'Banana'

Narcissist @'

Param ( [string]$String )
If ( $String -eq $MyInvocation.MyCommand.Definition ) { 'Accept' }
Else { 'Reject' }

'@

{{out}}

Reject
Accept

Python

{{Works with|Python|2}}

import sys
with open(sys.argv[0]) as quine:
    code = raw_input("Enter source code: ")
    if code == quine.read():
        print("Accept")
    else:
        print("Reject")

{{Works with|Python|3}}

_='_=%r;print (_%%_==input())';print (_%_==input())

Racket

This shows a REPL interaction, where the second expression is what is typed when the code stops to read some input.

-> ((lambda (x) (equal? (read) (list x (list 'quote x))))
   '(lambda (x) (equal? (read) (list x (list 'quote x)))))
((lambda (x) (equal? (read) (list x (list 'quote x))))
 '(lambda (x) (equal? (read) (list x (list 'quote x)))))
#t

REXX

version 1

(returns '''1''' or '''0''')

/*REXX*/ say arg(1)=sourceline(1)

version 2

(returns '''accept''' or '''reject''')

/*REXX*/ say word('reject accept',1+(arg(1)=sourceline(1)))

Ruby

Translation of the C version.

s = "s = %s%s%s; puts(gets.chomp == (s %% [34.chr, s, 34.chr]) ? 'accept' : 'reject')"; puts(gets.chomp == (s % [34.chr, s, 34.chr]) ? 'accept' : 'reject')

Output:

$ ruby narcissist.rb < narcissist.rb
accept

Scala

import scala.io.StdIn

object Narcissist extends App {
  val text = scala.io.Source.fromFile("Narcissist.scala", "UTF-8").toStream
  println("Enter the number of lines to be input followed by those lines:\n")
  val n = StdIn.readInt()
  val lines = Stream {
    StdIn.readLine()
  }
  if (lines.mkString("\r\n") == text) println("\naccept") else println("\nreject")
}

Sidef

say (File.new(__FILE__).open_r.slurp == ARGF.slurp);

Swift

#! /usr/bin/swift
import Foundation

let script = CommandLine.arguments[0]
print(script)
let mytext = try? String.init(contentsOfFile: script, encoding: .utf8)

var enteredtext = readLine()
if mytext == enteredtext {
    print("Accept")
} else {
    print("Reject")
}

Tcl

With the use of explicit reflexive introspection:

apply {{} {puts [expr {[gets stdin] eq [info level 0]}]}}

Without such commands, using pure generation of strings and lists:

apply {s {puts [expr {[gets stdin]eq[list {*}$s $s]}]}} {apply {s {puts [expr {[gets stdin]eq[list {*}$s $s]}]}}}

TXR

@(bind my64 "QChuZXh0IDphcmdzKUBmaWxlbmFtZUAobmV4dCBmaWxlbmFtZSlAZmlyc3RsaW5lQChmcmVlZm9ybSAiIilAcmVzdEAoYmluZCBpbjY0IEAoYmFzZTY0LWVuY29kZSByZXN0KSlAKGNhc2VzKUAgIChiaW5kIGZpcnN0bGluZSBgXEAoYmluZCBteTY0ICJAbXk2NCIpYClAICAoYmluZCBpbjY0IG15NjQpQCAgKGJpbmQgcmVzdWx0ICIxIilAKG9yKUAgIChiaW5kIHJlc3VsdCAiMCIpQChlbmQpQChvdXRwdXQpQHJlc3VsdEAoZW5kKQ==")
@(next :args)
@filename
@(next filename)
@firstline
@(freeform "")
@rest
@(bind in64 @(base64-encode rest))
@(cases)
@  (bind firstline `\@(bind my64 "@my64")`)
@  (bind in64 my64)
@  (bind result "1")
@(or)
@  (bind result "0")
@(end)
@(output)
@result
@(end)

{{out}}

$ txr narcissist.txr narcissist.txr
1

VBA

Based on the quine

Public Sub narcissist()
    quote = Chr(34)
    comma = Chr(44)
    cont = Chr(32) & Chr(95)
    rparen = Chr(41)
    n = Array( _
"Public Sub narcissist()", _
"    quote = Chr(34)", _
"    comma = Chr(44)", _
"    cont = Chr(32) & Chr(95)", _
"    rparen = Chr(41)", _
"    n = Array( _", _
"How many lines?", _
"Line ", _
"    x = InputBox(n(5))", _
"    flag = True", _
"    For i = 0 To 5", _
"        If InputBox(n(6) & i) <> n(i) Then flag = False", _
"    Next i", _
"    For i = 0 To 20", _
"        If InputBox(n(6) & i + 6) <> quote & n(i) & quote & comma & cont Then flag = False", _
"    Next i", _
"    If InputBox(n(6) & 27) <> quote & n(21) & quote & rparen Then flag = False", _
"    For i = 7 To 21", _
"        If InputBox(n(6) & i + 21) <> n(i) Then flag = False", _
"    Next i", _
"    Debug.Print IIf(flag, 1, 0)", _
"End Sub")
    x = InputBox(n(5))
    flag = True
    For i = 0 To 5
        If InputBox(n(6) & i) <> n(i) Then flag = False
    Next i
    For i = 0 To 20
        If InputBox(n(6) & i + 6) <> quote & n(i) & quote & comma & cont Then flag = False
    Next i
    If InputBox(n(6) & 27) <> quote & n(21) & quote & rparen Then flag = False
    For i = 7 To 21
        If InputBox(n(6) & i + 21) <> n(i) Then flag = False
    Next i
    Debug.Print IIf(flag, 1, 0)
End Sub

UNIX Shell

cmp "$0" >/dev/null && echo accept || echo reject

zkl

stdin:=File.stdin.read();
thisFileSrc:=File(System.argv[1]).read();
println((stdin==thisFileSrc) and "input matches "+System.argv[1] or "No match");

Since zkl is [usually] compile-when-run, we just compare the contents of source file to stdin. {{out}}

$ zkl narcissist.zkl <narcissist.zkl
input matches narcissist.zkl
$ zkl narcissist.zkl <narcissist3.zkl
No match

{{omit from|bc|Cannot read a file.}} {{omit from|dc|Cannot read a file.}} {{omit from|GUISS}}