Print itself

Print itself is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Create a program, which prints its source code to the stdout!

Related tasks

• Quine.
• Entropy/Narcissist.

11l

:start:
-V sourceFileName = fs:path:split_ext(:argv[0])[0]‘.11l’
print(File(sourceFileName).read())

Batch File

@echo off
for /f "tokens=*" %%s in (%~n0%~x0) do (echo %%s)

FreeBASIC

This works for Linux.

shell( "cat quine.bas" )

Furor

1 argv getfile dup sprint free
end

Go

package main

import (
    "fmt"
    "io/ioutil"
    "log"
    "os"
    "path"
)

func main() {
    self := path.Base(os.Args[0]) + ".go"
    bytes, err := ioutil.ReadFile(self)
    if err != nil {
        log.Fatal(err)
    }
    fmt.Print(string(bytes))
}

Output:

Just the invoking line as remainder is, of course, as above.

$ go run self_print.go

jq

Works with: jq

Works with gojq, the Go implementation of jq

A jq program that contains any JSON entity formatted as though by jq will print itself. The shortest such program would be a single digit, e.g.:

0

Output:

Example invocation: jq -n 0

0

Julia

The running program's filename is referenced as the builtin PROGRAM_FILE variable in Julia.

""" Read the program file and print it. """
printitself() = print(read(PROGRAM_FILE, String))

printitself()

Ksh

#!/bin/ksh

# Program to print it's own source code

 ######
# main #
 ######
while read line; do
	print "${line}"
done < $0

Lua

-- arg[0] contains the name of the invoked script.
print(io.open(arg[0]):read"*a")

Nanoquery

println new(Nanoquery.IO.File).open(args[1]).readAll()

Nim

We suppose that the source file is in the same directory as the executable file.

import os

let execFile = getAppFilename()
let sourceFile = execFile.addFileExt("nim")
stdout.write sourceFile.readFile()

Perl

# 20201011 added Perl programming solution

use strict;
use warnings;

open my $in, '<', $0 or die;
print while <$in>;
close($in)

# @ARGV=$0; print <> # slurp without an explicit open()

Phix

Interpreted only:

puts(1,get_text(command_line()[2]))

Output:

puts(1,get_text(command_line()[2]))

Interpreted or compiled - latter only works while executable and source are still in the same directory, and not renamed.

puts(1,get_text(substitute(command_line()[2],".exe",".exw")))

Output:

>p test ;; or p -c test
puts(1,get_text(substitute(command_line()[2],".exe",".exw")))

Alternative - see the docs (ie phix.chm) for an explanation of the ("") and [1][2]:

?get_text(include_path("")&include_files()[1][2])

Output:

"?get_text(include_path("")&include_files()[1][2])"

PowerShell

Write-Host $MyInvocation.MyCommand

Python

Works with: python3

import sys
with open(sys.argv[0],'r') as input:
    for row in input:
        print(row, end='')

Raku

Works with: Rakudo version 2020.05

Not really sure what the point of this task is.

Is it supposed to be a quine?

my &f = {say $^s, $^s.raku;}; f "my \&f = \{say \$^s, \$^s.raku;}; f "

Or just a program that when executed echoes its source to STDOUT? (Here's probably the simplest valid program that when executed, echoes its source to STDOUT. It is exceptionally short: zero bytes; and when executed echoes zero bytes to STDOUT.)

Or are we supposed to demonstrate how to locate the currently executing source code file and incidentally, print it.

print $*PROGRAM.slurp

Whatever. Any of these satisfy the rather vague specifications.

REXX

/*REXX program  prints  its own multi─line source to the  standard output  (stdout).    */

    do j=1  for sourceline()
    call lineout , sourceline(j)
    end   /*j*/                                  /*stick a fork in it,  we're all done. */

Ring

fileName = filename()
fp = fopen(fileName,"r")
? read(filename())
fclose(fp)

Output:

fileName = filename()
fp = fopen(fileName,"r")
? read(filename())
fclose(fp)

Wren

import "os" for Process
import "io" for File

var args = Process.allArguments
System.write(File.read(args[1]))

Output:

Just the invoking line as remainder is, of course, as above.

$ wren self_print.wren

Z80 Assembly

This program prints its bytecode as text to the Amstrad CPC terminal. The program is run by typing call &1000 to the screen.

WinAPE Z80 Assembler V1.0.13

000001  0000  (1001)        org &1001
000003  1001  21 01 10      ld hl,&1001
000004  1004  1E FF         ld e,&ff    ;0 is the terminator so we can't use zero as an immediate directly
000005  1006  1C            inc e       ;we have to abuse 8-bit underflow to get it.
000006  1007                loop
000007  1007  7E            ld a,(hl)
000008  1008  BB            cp e
000009  1009  CA 2B 10      jp z,ProgramEnd
000011  100C  CD 36 10      call UnpackNibbles
000012  100F  78            ld a,b
000013  1010  FE 0A         cp &0A
000014  1012  38 02         jr c,noCorrectHex_B
000015  1014  C6 07         add &07
000016  1016                noCorrectHex_B
000017  1016  C6 30         add &30
000018  1018  CD 5A BB      call &bb5a
000020  101B  79            ld a,c
000021  101C  FE 0A         cp &0A
000022  101E  38 02         jr c,noCorrectHex_C
000023  1020  C6 07         add &07
000024  1022                noCorrectHex_C
000025  1022  C6 30         add &30
000026  1024  CD 5A BB      call &bb5a
000027  1027  23            inc hl
000028  1028  C3 07 10      jp loop
000029  102B                ProgramEnd
000030  102B  3E 30         ld a,&30
000031  102D  CD 5A BB      call &bb5a
000032  1030  3E 30         ld a,&30
000033  1032  CD 5A BB      call &bb5a
000034  1035  C9            ret		;return to basic
000037  1036                UnpackNibbles
000038  1036                ;splits a into its component nibbles, storing high nibble in B and low in C.
000039  1036  F5            push af
000040  1037  E6 0F         and &0f
000041  1039  4F            ld c,a
000042  103A  F1            pop af
000043  103B  E6 F0         and &f0
000044  103D  0F            rrca
000045  103E  0F            rrca
000046  103F  0F            rrca
000047  1040  0F            rrca
000048  1041  47            ld b,a
000049  1042  C9            ret
000051  1043  00            db 0         ;this must be the only instance of 00 in the bytecode for this to work.

Output:

Output on WinAPE