add new lines to file without delete old one

RouterOS General
1

Hello ,
is there any why to add new line to file without delete the old one?

if I use this command -

/file set test.txt contents="123"

I will get in test.txt 123
and if I wan to add in line 2 “456” - how can I do this?

is it even possible?

so after i run the command twice I will see in test.txt
123
456

2

Despite the fact that the Linux kernel supports appending to files, RouterOS doesn’t expose that.

To append to a file, you need to instead get the current contents, concatenate the new contents onto it, and write out the full new contents.

e.g.

:local contents [/file get test.txt contents]
:set contents ($contents . "123")
/file set test.txt contents=$contents
3

O.K. - now its good , thanks

and if I want to go down a line every new entry
so it will be like
123
456
and not 123 456
how can I do this ? I have try to use “/n”

Thanks ,

4

Yes… Well, “\n”, not “/n”, but yes.

5

I have try both
maybe I’m writing something wrong?

 :global test [/file get test.txt contents]
 :set test ($test . "\n newline \n")
 :file set test.txt contents=$test
6

The new lines are not visible in Notepad, if that’s where you’re trying to view the file. Windows uses “\r\n” for its new lines.

(also, you really shouldn’t be using a :global variable for this)

7

yes - now it’s working
Thanks ,

the global is just I could see what am I doing
in the final script it will be “:local”

Thanks again ,

8

Just a follow up on this old post , How can I ensure new data is displayed as a individual line rather than a concatenate of a existing line ?