CODEWITHSUNDEEP
bashmultiline
ccpizza
ccpizza

Reputation: 31791

Bash: split long string argument to multiple lines?

Given a command that takes a single long string argument like:

mycommand -arg1 "very long string which does not fit on the screen"

is it possible to somehow split it in a way similar to how separate arguments can be split with \.

I tried:

mycommand -arg1 "very \
long \
string \
which ..."

but this doesn't work.

mycommand is an external command so cannot be modified to take single arguments.

Upvotes: 92

Views: 85424

Answers (3)

Константин Ван
Константин Ван

Reputation: 14819

I don’t want my strings to crawl along the left border. To keep the indentation, I do this.

join () {
    echo "$(IFS=; echo "$*")"
}

yourcommand\
    "$(
        join "your very long string"\
            " which does not fit"\
            " on the screen"
    )"

$* joins the arguments of the join function, with the IFS, that is temporarily set to be empty in a subshell, for the delimiter.

Upvotes: 1

Tom Fenech
Tom Fenech

Reputation: 74685

You can assign your string to a variable like this:

long_arg="my very long string\
 which does not fit\
 on the screen"

Then just use the variable:

mycommand "$long_arg"

Within double quotes, a newline preceded by a backslash is removed. Note that all the other white space in the string is significant, i.e. it will be present in the variable.

Upvotes: 111

Eremite
Eremite

Reputation: 8625

Have you tried without the quotes? 

$ foo() { echo -e "1-$1\n2-$2\n3-$3"; }

$ foo "1 \
2 \
3"

1-1 2 3
2-
3-

$ foo 1 \
2 \ 
3

1-1
2-2
3-3

When you encapsulate it in double-quotes, it's honoring your backslash and ignoring the following character, but since you're wrapping the whole thing in quotes, it's making it think that the entire block of text within the quotes should be treated as a single argument.

Upvotes: 9

Related Questions