Narcissist
You are encouraged to solve this task according to the task description, using any language you may know.
Quoting from the 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
Took code from Quine, has to be in one line (could be done pretty printed, too, but not as simple).
<lang Ada>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;</lang>
ALGOL 68
<lang algol68>STRINGs="STRINGs="";print(readstring=2*s[:9]+2*s[9:])";print(readstring=2*s[:9]+2*s[9:])</lang> Output: T or F depending on input.
C
Based upon the quine. Reads until EOF or newline from stdin, and writes "1" or "0" to stdout. <lang c>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)); }</lang>
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.
<lang go>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);};}</lang>
J
<lang j>#!/j602/bin/jconsole main=:3 : 0
self=: '#!/j602/bin/jconsole',LF,'main=:',(5!:5<'main'),LF,'main,LF echo self -: stdin
) main</lang>
Example use:
<lang>$ ./narcissist.ijs <narcissist.ijs 1
</lang>
Note that this assumes a suitable os command line.
JavaScript
Based upon one of the quines. Outputs 'true' if source is equal to inputted line (newline terminated), 'false' otherwise. <lang javascript>var code='var q=String.fromCharCode(39);print("var code=" + q + code + q + "; eval(code)" == readline())'; eval(code)</lang>
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.
<lang lb>
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)) </lang>
Perl
<lang perl># this is file narc.pl print do { local $/; open 0, $0 or die $!; <0> } eq <> ? "accept" : "reject"</lang> Run: <lang>perl narc.pl < narc.pl</lang>
PicoLisp
<lang PicoLisp>(de narcissist (Str)
(= Str (str narcissist)) )</lang>
Output:
: (narcissist "(Str) (= Str (str narcissist))") -> T
Python
For Python 2.x: <lang Python> import sys with open(sys.argv[0]) as quine:
code = raw_input("Enter source code: ")
if code == quine.read():
print("Accept")
else:
print("Reject")
</lang>
REXX
version 1
(returns 1 or 0) <lang rexx> /*REXX*/ say arg(1)=sourceline(1) </lang>
version 2
(returns accept or reject) <lang rexx> /*REXX*/ say word('reject accept',1+(arg(1)=sourceline(1))) </lang>
Ruby
Translation of the C version. <lang ruby>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')</lang> Output:
$ ruby narcissist.rb < narcissist.rb accept
Tcl
With the use of explicit reflexive introspection: <lang tcl>apply {{} {puts [expr {[gets stdin] eq [info level 0]}]}}</lang> Without such commands, using pure generation of strings and lists: <lang tcl>apply {s {puts [expr {[gets stdin]eq[list {*}$s $s]}]}} {apply {s {puts [expr {[gets stdin]eq[list {*}$s $s]}]}}}</lang>