regexbashsedpipeconcatenation

Concatenate in bash the output of two commands without newline character

What I need:

Suppose I have two commands, A and B, each of which returns a single-line string (i.e., a string with no newline character, except possibly 1 at the very end). I need a command (or sequence of piped commands) C that concatenates the output of commands A and B on the same line and inserts 1 space character between them.

Example of how it should work:

For example, suppose the output of command A is the string between the quotation marks here:

"The quick"

And suppose the output of command B is the string between the quotation marks here:

"brown fox"

Then I want the output of command(s) C to be the string between the quotation marks here:

"The quick brown fox"

My best attempted solution:

In trying to figure out C by myself, it seemed that the following sequence of piped commands should work:

{ echo "The quick" ; echo "brown fox" ; } | xargs -I{} echo {} | sed 's/\n//'

Unfortunately, the output of this command is

The quick
brown fox
Solution

  • You can use tr:

    { echo "The quick"; echo "brown fox"; } | tr "\n" " "

    OR using sed:

    { echo "The quick"; echo "brown fox"; } | sed ':a;N;s/\n/ /;ba'

    OUTPUT:

    The quick brown fox