C++ (Unix): Open a text file with the default editor

Question

The question is above and my Google search wasn't succesfull. I guess I need to get the default editor and then use system("editor file.txt");? How could I get the default editor?

Edit: I don't know why but stackoverflow doesn't like my "Hey,"... then not.

Possible duplicate of [Open file in default editor from bash](http://stackoverflow.com/questions/13627767/open-file-in-default-editor-from-bash). — Frédéric Hamidi, Jan 10 '14 at 13:31
@FrédéricHamidi Sorry but I can't aggree. That's not C++ and someone could give me an alternative to system(). — Vider7CC, Jan 10 '14 at 13:36
@FrédéricHamidi Ok thanks. Are there any disadvantages by using xdg-open instead of bin/sensible-editor(pts's answer)? — Vider7CC, Jan 10 '14 at 13:51
`xdg-open` is a freedesktop.org tool, `sensible-editor` is a Debian tool... I guess it depends on the platforms you want to support. — Frédéric Hamidi, Jan 10 '14 at 13:53
Indeed - the complexity of the solution is increased depending on which OSs you intend to support. You should also be aware that using a general purpose editor *could* introduce a big security hole. — Component 10, Jan 10 '14 at 13:58

pts · Accepted Answer · 2014-01-10T14:17:51.570

9

There is no official solution. Here is my recommendation for opening up a text editor:

If the filename extension is .txt, and xdg-open is avaliable on $PATH and the $DISPLAY variable is nonempty, then use xdg-open. Otherwise use /usr/bin/sensible-editor if it exists. Otherwise, use getenv("EDITOR"), getenv("VISUAL") or getenv("SELECTED_EDITOR"). If none of them are set, try nano, nano-tiny and then vi.

edited Jan 10 '14 at 14:17

answered Jan 10 '14 at 13:29

pts

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Worth adding: `xdg-open` is not "official part of C++", but it is part of the "most widely?" followed Linux desktop standard: https://freedesktop.org/wiki/ – Ciro Santilli OurBigBook.com Mar 20 '16 at 09:53

score 4 · Answer 2 · answered Jan 10 '14 at 14:36

There is an example to get default editor environment, from visudo (It use default editor to open sudoers file ) source

/*
     * Check EDITOR and VISUAL environment variables to see which editor
     * the user wants to use (we may not end up using it though).
     * If the path is not fully-qualified, make it so and check that
     * the specified executable actually exists.
     */
    if ((UserEditor = getenv("EDITOR")) == NULL || *UserEditor == '\0')
    UserEditor = getenv("VISUAL");
    if (UserEditor && *UserEditor == '\0')
    UserEditor = NULL;
    else if (UserEditor) {
    if (find_path(UserEditor, &Editor, getenv("PATH")) == FOUND) {
        UserEditor = Editor;
    } else {
        if (def_flag(I_ENV_EDITOR)) {
        /* If we are honoring $EDITOR this is a fatal error. */
        (void) fprintf(stderr,
            "%s: specified editor (%s) doesn't exist!\n",
            Argv[0], UserEditor);
        Exit(-1);
        } else {
        /* Otherwise, just ignore $EDITOR. */
        UserEditor = NULL;
        }
    }
    }

You can check http://www.opensource.apple.com/source/sudo/sudo-9/sudo/visudo.c for the complete code.

C++ (Unix): Open a text file with the default editor

2 Answers2