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Gaurav Agarwal
Asked: 2013-03-02 09:41:54 +0800 CST

Is 1.abc!``!+123 a valid file name?

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Is this a valid file name 1.abc!``!+123 in Ubuntu?

I issued the command 

rm 1.abc!``!+123

and got error message 

-bash: !``!+123: event not find

Why? How to I delete the file?

bash

2 Answers

  1. Best Answer

    Just simply rm '1.abc!``!+123'. Note about '

    Note:Quoting is used to remove the special meaning of certain characters or words to the shell. Quoting can be used to disable special treatment for special characters, to prevent reserved words from being recognized as such, and to prevent parameter expansion. Some special characters are: $ ` " !

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  2. Yes, that is a valid file name. However, the shell treats those as special characters, so to use them in a file command, you will need to escape them using ':

    rm '1.abc!``!+123'

    According to the bash manpage,

    ! Start a history substitution, except when followed by a blank, newline, carriage return, = or ( (when the extglob shell option is enabled using the shopt builtin).

    And

    Command Substitution

    Command substitution allows the output of a command to replace the command name. There are two forms:

    $(command)

    or

    `command`

    So if you want to use the ! or ` characters as regular characters, you need to escape them using ' so the shell doesn't try to start a history or command substitution.

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