I tried to create a script by echo'ing the contents into a file, instead of opening it with a editor

echo -e "#!/bin/bash \n /usr/bin/command args"  > .scripts/command

The output:

bash: !/bin/bash: event not found

I've isolated this strange behavior to the bang.

$ echo !

$ echo "!"
bash: !: event not found

$ echo \#!

$ echo \#!/bin/bash
bash: !/bin/bash: event not found
  • Why is bang causing this?
  • What are these "events" that bash refers to?
  • How do I get past this problem and print "#!/bin/bash" to the screen or my file?

6 Answers 6


Try using single quotes.

echo -e '#!/bin/bash \n /usr/bin/command args'  > .scripts/command

echo '#!'

echo '#!/bin/bash'

The problem is occurring because bash is searching its history for !/bin/bash. Using single quotes escapes this behaviour.

  • 5
    It also disables string interpolation :(
    – Hubro
    Jan 23, 2015 at 7:53
  • That's the point! You can add other arguments to the same echo command using double quotes and get interpolation on those parts.
    – Richm
    Jan 23, 2015 at 11:32
  • 3
    you can also use C style string in bash with $''. For example echo $'1!\n2!\n3!\n' prints each number followed by a bang and a newline.
    – spelufo
    Feb 19, 2015 at 14:34
  • 2
    Putting bang in single quotes didn’t help me when entering a multi-line string: !bash—single quotes do not escape bang (for real)
    – binki
    Mar 7, 2016 at 17:03
  • 1
    @kbolino You are right. So the full example string would be: echo '0123'"$var"'456', note two pairs of single quotes and one pair of double quotes.
    – phyatt
    Apr 9, 2018 at 19:26

As Richm said, bash is trying to do a history match. Another way to avoid it is to just escape the bang with a \:

$ echo \#\!/bin/bash

Though beware that inside double quotes, the \ is not removed:

$ echo "\!"
  • 13
    In bash, "\!" actually expands to \!, not !, supposedly for POSIX compliance.
    – Mikel
    Apr 7, 2011 at 23:09
  • @Mikel Sigh. So many differences between zsh and bash Apr 8, 2011 at 3:55
  • This works even when entering a multiline string. Remembering to 1. be outside of a string when entering the bang and 2. use this method (backslash) seems to work with the least surprise in most scenarios.
    – binki
    Mar 7, 2016 at 17:09
  • 1
    Would be useful to note that bash doesn’t do history searches when executing a script, so no need to do anything special for it there.
    – binki
    Mar 7, 2016 at 17:09
  • Isn't there any syntax to simply escape ! inside double quotes with no magic behavior? This is nuts...
    – Lassi
    Sep 5, 2019 at 15:55

! starts a history substitution (an “event” is a line in the command history); for example !ls expands to the last command line containing ls, and !?foo expands to the last command line containing foo. You can also extract specific words (e.g. !!:1 refers to the first word of the previous command) and more; see the manual for details.

This feature was invented to quickly recall previous commands in the days when command line edition was primitive. With modern shells (at least bash and zsh) and copy-and-paste, history expansion is not as useful as it used to be — it's still helpful, but you can get by without it.

You can change which character triggers history substitution by setting the histchars variable; if you rarely use history substitution, you can set e.g. histchars='¡^' so that ¡ triggers history expansion instead of !. You can even turn off the feature altogether with set +o histexpand.


To be able to disable history expansion on a particular command line, you can use space as the 3rd character of $histchars:

histchars='!^ '

Then, if you enter your command with a leading space, history expansion will not be performed.

bash-4.3$ echo "#!/bin/bash"
bash: !/bin/bash: event not found
bash-4.3$  echo "#!/bin/bash"

Note however that leading spaces are also used when $HISTCONTROL contains ignorespace as a way to tell bash not to record a command line in the history.

If you want both features indenpendantly, you'll need to choose another character as the 3rd character of $histchars. You want one that doesn't affect the way your command is interpreted. A few options:

  • using backslash (\): \echo foo works but that has the side effect of disabling aliases or keywords.
  • TAB: to insert it in first position, you need to press Ctrl+VTab though.
  • if you don't mind typing two keys, you can pick any character that normally doesn't appear in first position (%, @, ?, pick your own) and make an empty alias for it:

    alias %=

    Then enter that character, space and your command:

    bash-4.3$ % echo !!

(you won't be able not to record a command where history substitution has been disabled though. Also note that the default 3rd character of $histchars is # so that history expansion is not done in comments. If you change it, and you enter comments at the prompt, you should be aware of the fact that ! sequences may be expanded there).


The proposed solutions don't work in, e.g., the following example:

$ bash -c "echo 'hello World!'"
-bash: !'": event not found

In this case the bang can be printed using its octal ASCII code:

$ bash -c "echo -e 'hello World\0041'"
hello World!
  • 2
    In your first command, the ! is between double quotes, where as other answers indicate it retains its history expansion meaning. You could use bash -c 'echo '\''hello World!'\' or bash -c "echo 'hello World"\!"'". Dec 26, 2010 at 11:18
  • Without the -i parameter, the environment may be altered (like your ~/.profile doesn't run). However, doing -i means any output from your .profile will be captured in the output of the command you actually want to run.
    – Brent
    Apr 6, 2015 at 21:18

A simple solution not yet mentioned is to use a variable:

$ var='!'
$ echo -e "#${var}/bin/bash \n /usr/bin/command args"  > .scripts/command

Printing a bang! is not a problem when the string is unquoted or is single quoted or inside a C-String

$ echo hi\!pal 'hi!pal' $'hi!pal'
hi!pal 'hi!pal' $'hi!pal'

Nor it is a problem when histexpand is disabled ( either shopt -ou histexpand or set +o histexpand or simply set +H. It is also posible to change hisexpand characters to make it easier to print a bang!.

But the portable simplest solution is: use a var

$ var='!'
$ echo "hi${var}pal"

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