Shortest way to get an EOF Error

Question

It's simple, simply output text to STDERR containing the string EOF.

Input/Output

Your input will be none; however, you should output the message to STDERR.

Rules

• Since this is code-golf, the shortest answer wins.
• No standard loopholes please.
• Any method approved by Standard I/O is allowed.
• Your code may not contain the "EOF" that you will output as-is in your error.
• Outputting "EOI" is technically allowed, because the input can also be considered as a separate file.

Answer 1

APL (Dyalog Unicode) 17.0, 0 bytes

Dyalog 17.0 expects programs to terminate themselves cleanly and will throw an EOF INTERRUPT (and exit with a code 2) if they don't: Try it online!

In contrast, here is the minimal program which does terminate itself cleanly, causing no error (and code 0 upon exit): Try it online!

Answer 2

Python 3, 1 byte

(

Try it online!

A plain opening bracket is interpreted as the start of a tuple. Just having one bracket is enough to raise an EOF error. Also works with [ and {.

Answer 3

Keg, 1 byte

?

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When there's no input, an EOF is raised:

Traceback (most recent call last):
 File "/opt/keg/Keg.py", line 500, in <module>
   exec(header + code + footer)
 File "<string>", line 6, in <module>
 File "/opt/keg/KegLib.py", line 119, in Input
   item = input()
 EOFError: EOF when reading a line

Also works with ¿

Answer 4

JavaScript, 1 byte / 7 solutions

The following tokens trigger SyntaxError: Unexpected end of input, or a similar message depending on the JS engine.

!
(
+
-
[
{
~

Or to summarize:

• unary operators
• opening parenthesis / bracket / brace

Exhaustive test on all ASCII characters

for(n = 0; n < 127; n++) {
  code = String.fromCharCode(n);
  res = false;

  try {
    eval(code);
  }
  catch(e) {
    res = e.toString() == 'SyntaxError: Unexpected end of input';
  }
  if(res) {
    console.log(code);
  }
}

Try it online!

Answer 5

Turbo Assembler, 0 bytes

Borland Turbo Assembler will print an "Unexpected end of file" when assembling a zero-byte file.

Answer 6

For the python users; the ones posting one character code, technically that is a SyntaxError which happens to read as an EOFERROR. (FYI, here's an example of all printable single characters that would cause this same error I'm getting a total of 34:)

from string import printable

chars = []
for c in printable:
    try: eval(c)
    except Exception as e:
        if 'EOF' in str(e):
            chars += [c]
print(chars)

This prints:

['!', '#', '$', '%', '&', '(', ')', '*', '+', ',', '-', '.', '/', ':', ';', '<', '=', '>', '?', '@', '[', ']', '^', '`', '{', '|', '}', '~', ' ','\t', '\n', '\r', '\x0b', '\x0c']

I'm not sure if raise EOFError would be considered an answer as unfortunately that's the shortest code I can think of to raise a legitimate EOFError in Python 3:

---

Python 3, 14 bytes

raise EOFError

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OR

Without implicitly raising the error in Python 2 you could use this at the expense of an extra byte:

---

Python 2, 15 bytes

input('\u0004')

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Answer 7

PHP, 1 byte

1

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Run like this: php -r 1

Error: PHP Parse error: syntax error, unexpected end of file in ...

Any other characters apart from ;, #, space and new line should cause a similar error. So PHP probably has ASCII characters count - 4 single byte solutions.

Answer 8

Haskell using hugs, 1 byte

{

The error message contains unexpected end of input.

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Answer 9

Japt v2.0a0, 1 byte

Each throws: SyntaxError: Unexpected end of input

´
¥
¶
ª
©
«
§
¨
±
µ
÷
Á
Â
Ò
Ó

Test it (Errors are displayed below the output field)

There are also a number of other possibilities, not specific to Japt, that are covered in Arnauld's JS solution, such as:

!
&
|
~
^

Answer 10

R, 1 byte, 10 solutions

Any of these characters alone will trigger Error: unexpected end of input.

"
'
`
(
{
+
-
!
?
~

Answer 11

Python 3, 1 byte

Sorry for the edit, misunderstood the question at first :P. We can do [ or ( or { to get unexpected EOF error. In first case, it expects a list, in second a tuple and so on.

[

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Answer 12

Perl, 1 byte

(

Try it with

 perl -e "("
 syntax error at -e line 1, at EOF
 Execution of -e aborted due to compilation errors.

Answer 13

T-SQL, 21 bytes

RAISERROR('EOF',11,1)

Answer 14

Bash, 1

"

Output

.code.tio: line 1: unexpected EOF while looking for matching `"'
.code.tio: line 2: syntax error: unexpected end of file

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Answer 15

Ruby, 1 byte

!

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Any of ["!", "(", "*", "+", "-", ":", "[", "{", "~"] will work depending on the environment.

Answer 16

Ruby, 1 byte

/ 

Outputs unterminated regexp meets end of file

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Answer 17

Perl 5, 1 byte

"

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Not very inspired, but it is the shortest possible in the language.

Outputs Can't find string terminator '"' anywhere before EOF at .code.tio line 1.

Answer 18

Go, 0 bytes

All Go files must begin with package [identifier]. The error message is:

can't load package: package main: 
src/test.go:1:1: expected 'package', found 'EOF'

Answer 19

Java, 1 byte

e

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---

Old method that's more fun :]

void a()throws Exception{new java.io.DataInputStream(System.in).readInt();}

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