How to split strings over multiple lines in Bash?

bash line indentation
user880248 picture user880248 · Sep 6, 2011 · Viewed 166.6k times · Source

How can i split my long string constant over multiple lines?

I realize that you can do this:

echo "continuation \
lines"
>continuation lines

However, if you have indented code, it doesn't work out so well:

    echo "continuation \
    lines"
>continuation     lines

Answer

Ray Toal picture Ray Toal · Sep 6, 2011

This is what you may want

$       echo "continuation"\
>       "lines"
continuation lines

If this creates two arguments to echo and you only want one, then let's look at string concatenation. In bash, placing two strings next to each other concatenate:

$ echo "continuation""lines"
continuationlines

So a continuation line without an indent is one way to break up a string:

$ echo "continuation"\
> "lines"
continuationlines

But when an indent is used:

$       echo "continuation"\
>       "lines"
continuation lines

You get two arguments because this is no longer a concatenation.

If you would like a single string which crosses lines, while indenting but not getting all those spaces, one approach you can try is to ditch the continuation line and use variables:

$ a="continuation"
$ b="lines"
$ echo $a$b
continuationlines

This will allow you to have cleanly indented code at the expense of additional variables. If you make the variables local it should not be too bad.

Related questions

How do you run a command for each line of a file?

For example, right now I'm using the following to change a couple of files whose Unix paths I wrote to a file: cat file.txt | while read in; do chmod 755 "$in"; done Is there a more elegant, safer way?

Read More
How to delete and replace last line in the terminal using bash?

I want to implement a progress bar showing elapsed seconds in bash. For this, I need to erase the last line shown on the screen (command "clear" erases all the screen, but I need to erase only the line of …

Read More
Number of non repeating lines - unique count

Here is my problem: Any number of lines of text is given from standard input. Output: number of non repeating lines INPUT: She is wearing black shoes. My name is Johny. I hate mondays. My name is Johny. I don't …

Read More