Menu
I have a text like this:
foo bar `which which` If I do this using heredoc, I get a blank file:
➜ ~ echo <<EOT > out heredoc> foo bar heredoc> `which which` heredoc> EOT ➜ ~ cat out ➜ ~ How can I do this?
Oh sorry, I meant to do cat. Problem is that it writes this to the file: which: shell built-in command, ie, evaluations backticks. Any way to do this without evaluating?
With cat, I get
➜ ~ cat <<EOT > out heredoc> foo bar heredoc> `which which` heredoc> EOT ➜ ~ cat out foo bar which: shell built-in command ➜ ~ I don't want which which to be evaluated.
287
The basic functionality of backticks The Open Group has a definition for the backtick operator, officially referred to as command substitution. This operator is not the single quote character, but another character known as the grave accent ( ` ).
The back quote is the one to use when you want to assign output from system commands to variables. It tells the shell to take whatever is between the back quotes as a system command and execute its output. Using these methods you can then substitute the output into a variable.
A HereDoc is a multiline string or a file literal for sending input streams to other commands and programs. HereDocs are especially useful when redirecting multiple commands at once, which helps make Bash scripts neater and easier to understand.
Quote the label to prevent the backticks from being evaluated.
$ cat << "EOT" > out foo bar `which which` EOT $ cat out foo bar `which which` If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
