Bash: add string to the end of the file without line break

Question

How can I add string to the end of the file without line break?

for example if i'm using >> it will add to the end of the file with line break:

cat list.txt
yourText1
root@host-37:/# echo yourText2 >> list.txt
root@host-37:/# cat list.txt
yourText1
yourText2

I would like to add yourText2 right after yourText1

root@host-37:/# cat list.txt
yourText1yourText2

here may be [the answer you want](https://unix.stackexchange.com/questions/412835/append-text-with-echo-without-new-line); Note that if you also want to use a variable in sed comman, variable in single quote would not get expended, use double quote instead. — GG.Fan, Jun 27 '22 at 08:09

score 74 · Answer 1 · answered Jan 05 '12 at 08:17

74

You can use the -n parameter of echo. Like this:

$ touch a.txt
$ echo -n "A" >> a.txt
$ echo -n "B" >> a.txt
$ echo -n "C" >> a.txt
$ cat a.txt
ABC

EDIT: Aha, you already had a file containing string and newline. Well, I'll leave this here anyway, might we useful for someone.

answered Jan 05 '12 at 08:17

Franz

1,993
13
20

very proper, sir that is how I would carry it out. plus if you're not starting with a file then `>>` will touch it with any extenion you give or none at all, for example one my favorite lines of code: `$ cat ~/.ssh/id_rsa.pub | ssh itsme@nopasswordcheckneeded.com 'cat >> ~/.ssh/authorized_keys'` then the next line is `$ ssh-add -K` and walla! no more password prompt every time I need to remote onto that machine – Bent Cardan Jul 05 '13 at 20:35

score 13 · Answer 2 · answered Nov 23 '15 at 22:47

13

Just use printf instead, since it does not print the new line as default:

printf "final line" >> file

Test

Let's create a file and then add an extra line without a trailing new line. Note I use cat -vet to see the new lines.

$ seq 2 > file
$ cat -vet file
1$
2$
$ printf "the end" >> file
$ cat -vet file
1$
2$
the end

answered Nov 23 '15 at 22:47

fedorqui

275,237
103
548
598

2

For a very obscure reason `echo -n` didn't work when ran from Ansible shell. Your answer made my day. – Laurent Caillette Feb 14 '16 at 12:12

Dimitre Radoulov · Accepted Answer · 2012-01-05T08:22:24.173

6

sed '$s/$/yourText2/' list.txt > _list.txt_ && mv -- _list.txt_ list.txt

If your sed implementation supports the -i option, you could use:

sed -i.bck '$s/$/yourText2/' list.txt

With the second solution you'll have a backup too (with first you'll need to do it manually).

Alternatively:

ex -sc 's/$/yourText2/|w|q' list.txt

or

perl -i.bck -pe's/$/yourText2/ if eof' list.txt

edited Jan 05 '12 at 08:22

answered Jan 05 '12 at 08:15

Dimitre Radoulov

27,252
4
40
48

Thanks for the ex / vim version so simple! – Nick Mar 08 '13 at 16:23
Note: if your text file comes from Mac/Dos, this will not identify the EoL character. You'll need to run dos2unix on the file first. – adam.r Apr 30 '14 at 17:33

score 0 · Answer 4 · answered Mar 01 '19 at 19:38

The above answers didn't work for me. Posting a Python implementation in case anyone finds it useful.

python -c "txtfile = '/my/file.txt' ; f = open(txtfile, 'r') ; d = f.read().strip() ; f.close() ; d = d + 'the data to append' ; open(txtfile, 'w').write(d)"

Bash: add string to the end of the file without line break

4 Answers4

Test

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