How can I open a file read-only from command line with emacs/vi/vim

Question

Is there a way to tell emacs/vi/vim (from the command line) that I want to view the file in view-mode or read-only.

I know how to open a file as read only if emacs/vi/vim is already running.

Note: if you don't have the write permission to the file, Vim will by default open it in read-only mode. Actually, I think it is easier to control the file permission than to provide a "read-only" way. — Franklin Yu, Aug 02 '16 at 23:00

score 149 · Answer 1 · answered Oct 28 '10 at 09:51

149

vim -R filename

answered Oct 28 '10 at 09:51

RedGrittyBrick

81,981
20
135
205

5

Works great but I accepted Trey's answer because I prefer emacs over vim – Nifle Oct 29 '10 at 06:35
33

And all vim users take revenge by upvoting it to more than the "accepted answer" :D – Xosofox Nov 11 '15 at 09:33
1

Note: some boxes seem to have 'view' command maybe aliases to 'vi -R'. – armyofda12mnkeys Aug 10 '17 at 19:31

score 52 · Accepted Answer · edited Oct 29 '10 at 06:33

52

For emacs:

emacs FILE --eval '(setq buffer-read-only t)'

There's no startup option to force read only.

Edit:
If you put this small function in your shell startup script (.bashrc for example) you can open a file read-only by typing ev file_to_view

ev() {
  emacs "$1" --eval '(setq buffer-read-only t)'
}

edited Oct 29 '10 at 06:33

Nifle

34,203
26
108
137

answered Oct 28 '10 at 13:50

Trey Jackson

3,951
23
25

11

I wish I could downvote emacs for this. – Robert Calhoun Aug 29 '14 at 15:11
2

To open more than one file, the "-eval ..." has to be repeated after every filename, otherwise only the last file in the list is opened read-only. – stafusa Jul 19 '20 at 00:09
1

Quick n dirty hack to work with multiple files opened on the command line: `emacs --eval "(add-hook 'find-file-hook (defun make-read-only () (setq buffer-read-only t)))" file1 file2 ...` – Winny Mar 01 '21 at 15:22
3

See also [emacs FILE -f view-mode](https://superuser.com/a/1293797/568188) answer. – Y. E. Aug 03 '21 at 20:30

score 26 · Answer 3 · edited Aug 16 '13 at 12:33

26

view filename

Basically vim in read-only mode; simples!

As hinted by comment, in case view is linked to plain vi, here are bash commands to first inspect situation and then fix it:

# non-destructive inspection
which vim
which view
ls -l $(which view)

# overwrite current view with symlink to vim, requires root
ln -sfv $(which vim) $(which view)

edited Aug 16 '13 at 12:33

Jawa

3,619
13
31
36

answered Oct 28 '10 at 10:43

mrverrall

874
7
5

1

No syntax highlighting though. – Nifle Oct 28 '10 at 11:59
7

@Nifle: There shouldn't be any difference in syntax highlighting. If your `vim` has syntax highlighting but your `view` doesn't, perhaps your `view` is a link to a minimal version of `vim` that doesn't have syntax highlighting compiled in. Compare the outputs of the `:version` command. – garyjohn Oct 28 '10 at 15:33
1

Reason why it "just works": Vim will actually read `argv[0]` to decide its behavior. It's a common trick; AFAIK sometimes GCC and Bash does this as well. – Franklin Yu Aug 02 '16 at 22:57

Jay · Answer 4 · 2010-10-28T18:29:19.037

vim -R <file>

allows writing with :w!

vim -c ":set nomodifiable"  <file>

Prevents the user from making any changes to the file in the buffer. But the user could make the buffer modifiable with :set modifiable

You could use

vim -c ":noremap q :q<cr>" -c ":map : <Esc>" -c ":set nomodifiable" <file>

to prevent the user from turning off the "nomodifiable", and allow the user to quit by pressing q. But, then the user can't enter command mode at all, which may or may not be what you want.

You could also open the file with the less command:

less <file>

To view the file in a vim-like environment but without the ability to change the file.

+1 for using `less`, although as @nxdrvr points out you can press the ___v___ key to open the file in editiable mode in `vi` — Sheharyar, Jan 19 '15 at 02:11

score 9 · Answer 5 · answered Oct 31 '12 at 23:50

Small follow-up to the accepted answer: You can alias this in your shell to reduce it to a single command. For example in bash you can put the following in your .bashrc:

emacsro() {
  emacs $1 --eval '(setq buffer-read-only t)'
}

(different shells will have different formats for doing this, but you get the idea)

I would have added this as a comment in reply to the accepted answer, but it didn't seem possible to have a multi-line "code" block in a comment, and (in bash anyway) the above code really does need to be on 3 separate lines.

score 6 · Answer 6 · answered Feb 10 '18 at 18:37

6

In emacs you can do

emacs FILE -f view-mode

Syntax highlighting is applied. It doesn't just open the file as a read only buffer. Some commands, such as I-search, are accessible without the control key in this mode.

answered Feb 10 '18 at 18:37

jogama

61
1
2

score 6 · Answer 7 · 2012-09-12T15:34:18.243

6

For emacs you can also use the view-mode.

emacsclient --create-frame --eval '(view-file "/tmp/EXAMPLE")'

or alternative inside a terminal:

emacsclient --nw --eval '(view-file "/tmp/EXAMPLE")'

Or you can use my wrapper script

edited Sep 12 '12 at 15:34

answered Sep 12 '12 at 15:01

score 6 · Answer 8 · edited Jan 19 '15 at 08:42

6

To just view file without ability to edit:

cat <file> | less

In less you can go to "edit file mode" by pressing the v key. But you cannot edit standard input, so piping the output of cat <file> to less, stops less from going to 'edit' mode on pressing 'v'.

For vim the same approach

cat <file> | vim -

edited Jan 19 '15 at 08:42

Sheharyar

317
1
13

answered Mar 21 '14 at 08:32

nxdrvr

61
1
2

4

Thanks for the `v` suggestion. Nifty. – tshepang Apr 04 '14 at 09:08
2

+1, but no need for `cat`. Just use ` – Sparhawk Oct 09 '14 at 05:07
@Sparkhawk, ` less` would give an error, I'm assuming you meant `less `, but as explained in the answer, when using `less` directly, the user could press ___v___ key and go into edit-mode. Piping `cat` to `less` stops this from happening. – Sheharyar Jan 19 '15 at 02:30
@Sheharyar He meant output redirection. Maybe you are more familiar with `less < FILENAME`, which gives you "Cannot edit standard input" when you press *V*. Similarly with Vim: `vim - < FILENAME`. – Franklin Yu Aug 02 '16 at 22:45

score 0 · Answer 9 · answered Mar 15 '18 at 12:54

I am not going to discrad to anyone user answer here, but i would like to aadd some more info about Read-only Mode file. As per oreilly documentation Read-only Mode There will be times when you want to look at a file but want to protect that file from inadvertent keystrokes and changes. (You might want to call in a lengthy file to practice vi movements, or you might want to scroll through a command file or program). You can enter a file in read-only mode and use all the vi movement commands, but you won't be able to change the file.

To look at a file in read-only mode, enter either:

$ vi -R file

or:

$ view file

(The view command, like the vi command, can use any of the command-line options for advancing to a specific place in the file.) If you do decide to make some edits to the file, you can override read-only mode by adding an exclamation point to the write command:

:w!
or:

:wq!

If you have a problem writing out the file.

For further ref here

score 0 · Answer 10 · answered Oct 28 '10 at 18:45

0

sending a file to std out, may be acceptable given the size of the file

cat <file>  # dump whole file to stdout
head <file> # view the first few lines
tail <file> # view the last n lines

answered Oct 28 '10 at 18:45

Nathan Feger

173
1
5

How can I open a file read-only from command line with emacs/vi/vim

10 Answers10