How to print "-n" without issuing a newline?

Question

I'm trying to print -n using the echo command. But if i simply type echo -n, it only issues a newline, not show up -n, instead it issues a newline.

Solution 1

The problem is that echo interprets the -n as an argument. On the default bash implementation, that means (from help echo):

  -n  do not append a newline

There are various ways of getting around that:

1. Make it into something that isn't an option by including another character. For example, tell echo not to print a newline with -n, then tell it to interpret backslash escapes with -e and add the newline explicitly.

   $ echo -ne '-n\n'
   -n
   

2. Alternatively, just include a space

   $ echo " -n"
    -n
   

   That, however, adds a space which you probably don't want.

3. Use a non-printing character before it. Here. I am using the backspace (\b)

   $ echo -e "\b-n"
   -n
   

   This also adds an extra character you probably don't want.

4. Use trickery

   $ echo n- | rev
   -n
   

   The rev command simply prints its output reversed.

5. Use the right tool for the job

   $ printf -- '-n\n'
   -n
   

Solution 2

Sometimes it's a good idea to use the right tool. You could use printf instead:

% printf "-n\n"       
-n

Solution 3

You can use this command, but it adds an extra space.

echo -e  "\r-n"

This is a kind of a hack.

-e enables backslash command symbols.

\r is a carriage return.

Actually any \ valid character will do in any place of the string.

You can see which are valid by help echo.

echo "-n" does not work because -n is used as a parameter for echo.

P.S. The best solution IMHO is

echo -e "-n\c"

It does not add any extra characters.

echo -e "-n\n"

prints the same but with a new line char.

Solution 4

You guys are really overthinking it.

 echo -e \\055n

Or with no trailing newline

 echo -en \\055n

Solution 5

I think if you definitely want to use echo only, this should satisfy you:

echo "-n "

This works because while -n is a valid option for echo, -n with a space after it is not. Since it isn't an option, echo just prints it.

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Comments

[n0rd]

Does echo -n -- -n work (don't have any linux box handy to test)?

[Star OS]

I'm installing Ubuntu in a virtual machine and it seems to be very slow, wait.

[n0rd]

I've checked - it does not. Probably because it's internal bash command and it's not using getopt (???) to parse command line

[Brandin]

This question is asked and answered in pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html - - "Conforming applications that ... could possibly be expecting to echo a -n, should use the printf utility derived from the Ninth Edition system"

[Star OS]

... 100 reputation on all of my communities? Nice reward, moderators!

[Sadi]

Wov! This is better than mine; can you explain a bit for "beginners" ;-)

[Sadi]

Thanks, I've also noticed that it doesn't matter where you add the carriage return, at the beginning or the end.

[Pilot6]

You are correct that any `\` valid character will do.

[terdon]

@Pilot6 yeah but the problem with that approach (yours and mine) is that it adds an extra character. That can cause issues down the line. Especially if you then want to parse it and try something like grep '^-n'. pritnf is the way to go, really.

[Pilot6]

Well, printf is better anyway, but the question is regarding just echo.

[terdon]

@Sadi yes, that's because adding anything makes it a non-valid option. -n is valid, -nfoo is not so that will be printed.

[Pilot6]

@terdon man echo has it too. But help is a bit better.

[terdon]

I know it has it, it's just not relevant. /bin/echo is a completely different thing and when you run echo in bash, you get the builtin which can be quite different depending on your shell.

[Pilot6]

It looks like echo -e "-n\c" does the exact thing.

[terdon]

@Pilot6 nice! What is \c? I don't see it in man ascii. Also, I just realized that echo -ne '-n\n' prints -n\n and only that, just as desired.

[Pilot6]

\c is suppress further output

[terdon]

@Pilot6 ah, it's an echo-specific thing. Good to know, thanks!

[Pilot6]

Did you try it? It is wrong.

[user12205]

@Pilot6 Did you try it? It is not wrong.

[Pilot6]

First command outputs -pilot6@Pilot6:~$. The second outputs n.

[user12205]

@Pilot6 Depends on whether you're running it in interactive terminal or in a bash script, which isn't specified in the question. OTOH if you need it in the terminal it is simple to just combine the two lines with && - I wouldn't really say this answer is wrong.

[Benubird]

You can also print the extra character, and then erase it: echo -e "- \x08n"

[abligh]

Yup, I just answered this way. Will delete my answer. This is relatively portable in that it works with built-in echo and /bin/echo at least if invoked as echo -e "\055n"

[123]

\b is backspace, \a is a bell.

[200_success]

This is a good idea, since there are many variants of echo, while printf is better standardized.

[Star OS]

-en is not what i want.

[Star OS]

I've you're gonna extend an answer, please edit the answer.

[Star OS]

I'll edit it so it becomes much clearer it's for a bash script.

[Star OS]

Most viewers here may only want "-n", not "-n ".

[Dmitry Grigoryev]

I'm not sure it's a good idea to alter someone else's answer to the point when it will have more text from me than from the original author.

[Star OS]

Ash? Ash? POKEMON i mean, what?

[Sergiy Kolodyazhnyy]

This is a preferred idea for portability

[jiwopene]

I ran 'busybox ash'

[Star OS]

Say "Busybox" or "Busybox Ash". Not just "Ash" beacuse people may think of that pokemon character or the ******* ash from volcanoes.

[Star OS]

Better. alt255alt255

[Star OS]

This uses trickery. You can print anything with it. For example, this prints "cats": echo -n c ; echo -n a ; echo -n t ; echo s If it was echo 2 ; echo 3, it would output 2 in line 1 and 3 in line 2. By doing -n to all of these except the last it would bring all the characters to line 2. So -(line1)n(line2) becomes (line1)-n(line2)

[muru]

@StarOS ash is the name of the Almquist Shell.

[Star OS]

Just some explanation about how it works ^^^