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.

Batch File

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

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

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()
 

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