26

Is there a way to edit a file if there are no vi, vim, joe, mcedit? In another words is there a way to edit a file using just the shell commands?

  • 1
    I don't have nano, either! – Eduard Florinescu Aug 20 '12 at 19:26
  • 1
    Its a router, but also I've seen also a custom gateway in this situation :) – Eduard Florinescu Aug 20 '12 at 19:32
  • 1
    Make a copy of the file you want to edit. Then do cat file, followed by cat >file and arrange the parts with cut+paste and/or typing, finish with ctrl-d. – ott-- Aug 20 '12 at 20:08
  • 7
    This also happened to me, in docker.. It is very minimalistic. Now how the heck do i do something like that. The VM is ephemeral, i cannot ssh nor ftp, i have to use redirection and hacks like sed to change some files. It was a great challenge. See how reliant we are on editors :P – code ninja Jun 26 '14 at 21:33
  • 2
    If this is a container or accessed via some other host you can use echo <<EOF > new.file [paste here] EOF. Edit contents of file on host PC. – pztrick Aug 22 '17 at 23:16
15

In that instance, I'd try transferring files out and editing them on another computer, then transfer them back. If you have ssh, you should have scp (I hope), so you should be able to push files in and out. If not, you can also look for ftp to transfer files in and out.

If not, then I think your best option is to try and make use of cat, grep, sed, echo, and I/O redirection (especially append with >>). And lots of temporary files.

Though if you have access to perl (or something similar), you can run it with no arguments and it will let you input a script source from standard input. Once you press ctrl+d, it can then run the script. You could use that method to create a file. It would be more powerful than hacking something on the command line as I mentioned before.

  • no sshd but I have telnetd – Eduard Florinescu Aug 20 '12 at 19:37
  • Then can you ftp? – Ben Richards Aug 20 '12 at 19:38
  • 1
    I can use cat, grep, echo, and I/O redirection (especially append with >>) but no sed – Eduard Florinescu Aug 20 '12 at 19:42
  • 2
    Ftp works :) now I need to see where on this router do I have something that is writable. – Eduard Florinescu Aug 20 '12 at 19:50
  • 3
    If you are connected to your device via telnet, I'd seriously think about just catting the file to the terminal (with a sufficiently large backscroll buffer), copy/pasting the entire thing into a local editor, making your changes, and then whipping up something that will turn that into a series of echo commands that will write a replacement file. – afrazier Aug 20 '12 at 19:50
4

I imagine you could do what you need with grep and perl - look for the line you want with grep, edit that line with perl (perl can act like a big replacement for sed) and then confirm you didn't make more changes than you intended by doing diff filename filename.new. If so, make the changes permanent - mv filename.new filename

3

Assuming you're SSH'ing into your router, you can also use various utilities to transfer the file back and fourth to your computer/router. You can download a copy on your PC, modify it, and then SSH it back to the router via SFTP (see Putty or WinSCP if you're a Windows user).

If you're using a custom firmware on the router/gateway, however, you may be in luck. There are various Optware packages containing simple (and small) text editors. Depending on your needs, you could get the nano package, or just go for busybox which contains vi.

2

One way would to be to output the result of an echo.

echo "foo" > bar.txt

This will make a file titled bar.yxy with the containing text, "foo".

  • 3
    That's not really editing. – DavidPostill Jul 23 '16 at 22:50
  • 2
    Gets the job done, untill you can get an editor on it. – Landon Jul 25 '16 at 7:40
1

Did you wipe out /bin or something? Otherwise maybe you could hack something together with the text utilities in the GNU Coreutils that should be standard on a linux system.

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Not the answer you're looking for? Browse other questions tagged or ask your own question.