how do I echo $something >> file.txt without carriage return?

When I echo $something >> file.txt, a new line will be append to the file.

What if I want to append without a new line?

4 Answers

That's what echo -n is for .

printf is very flexible and more portable than echo. Like the C/Perl/etc implementations, if you do not terminate the format string with \n then no newline is printed:

printf "%s" "$something" >> file.txt

If you are using command's output, you can use xargs in combination with echo

/sbin/ip route|awk '/default/ { print $3 }' | xargs echo -n >> /etc/hosts

tr is another alternative.

If you're using echo as your input you can get away which tr -d '\n'.

This technique also works when piping in output from other commands (with only a single line of output). Moreover, if you don't know whether the files have UNIX or DOS line endings you can use tr -d '\n\r'.

Here are some tests showing that this works.

Newline included:

something='0123456789' ; echo ${something} | wc -c
11

UNIX newline:

something='0123456789' ; echo ${something} | tr -d '\n\r' | wc -c
10

DOS style:

something='0123456789' ; echo ${something} | unix2dos | tr -d '\n\r' | wc -c
10

Tested with BSD tr and GNU tr.