file_edit: Invoke an external text editor for a file

In svMisc: 'SciViews' - Miscellaneous Functions

Description

Edit a text file using an external editor. Possibly wait for the end of the program and care about creating the file (from a template) if it does not exists yet.

Usage

file_edit(
  ...,
  title = files,
  editor = getOption("fileEditor"),
  file.encoding = "",
  template = NULL,
  replace = FALSE,
  wait = FALSE
)

fileEdit(
  ...,
  title = files,
  editor = getOption("fileEditor"),
  file.encoding = "",
  template = NULL,
  replace = FALSE,
  wait = FALSE
)

Arguments

...	Path to one or more files to edit.
title	The title of the editor window (not honored by all editors, most external editors only display the file name or path).
editor	Editor to use. Either the name of the program, or a string containing the command to run, using \ the filename in the command, or a function with 'file', 'title' and 'wait' arguments to delegate process of the files.
file.encoding	Encoding of the files. If "" or native.enc, the files are considered as being already in the right encoding.
template	One or more files to use as template if files must be created. If NULL, an empty file is created. This argument is recycled for all files to edit.
replace	Force replacement of files if template= is not null.
wait	Wait for edition to complete. If more than one file is edited, the program waits sequentially for each file to be edited in turn (with a message in the R console).

Value

The function returns TRUE if it was able to edit the files or FALSE otherwise, invisibly. Encountered errors are reported as warnings.

Note

The default editor program, or the command to run is in the fileEditor option (use getOption("fileEditor") to retrieve it, and options(fileEditor = "<my_own_editor>") to change it). Default values are determined automatically.

On Unixes, "gedit", "kate" and "vi" are looked for in that order. Note that there is a gedit plugin to submit code directly to R: http://rgedit.sourceforge.net/. Since, gedit natively supports a lot of different syntax highlighting, including R, and is lightweight but feature rich, it is recommended as default text editor for file_edit() on Unixes. If JGR is run and the editor is "vi" or "internal", then the internal JGR editor is used, otherwise, the provided editor is chosen.

On MacOS, if the "bbedit" program exists, it is used (it is the command line program installed by BBEdit, see http://www.barebones.com/products/, a much more capable text editor than the default TextEdit program), otherwise, the default text editor used by MacOS is chosen (default usually to TextEdit). BBEdit can be configured to highlight and submit R code.It features also several tools that makes it a much better choice than TextEdit for file_edit() on MacOS. Specify "bbedit" to force using it. The default value is "textedit", the MacOS default text editor, but on R.app, and with wait = FALSE, the internal R.app editor is used instead in that case. If RStudio or JGR is run, and the editor is "textedit", "internal" or "vi", then, the RStudio or JGR internal editor is used instead. If wait = TRUE with an RStudio editor, it is enough to switch to another editor to continue.

On Windows, if Notepad++ is installed in its default location, it is used, otherwise, the default "notepad" is used in Rterm and the internal editors are chosen for Rgui. Notepad++ is a free text editor that is much better suited to edit code or text files that the default Windows' notepad application, in particular because it can handle various line end types (Unix, Mac or Windows) and encodings. It also supports syntax highlighting, code completion and much more. So, it is strongly recommended to install it (see http://notepad-plus-plus.org/) and use it with file-edit(). There is also a plugin to submit code to R directly from Notepad++: https://sourceforge.net/projects/npptor/.

Of course, you can use your own text editor, just indicate it in the fileEditor option. Note, however, that you should use only lightweight and fast starting programs. Also, for the wait = TRUE argument of file_edit(), you must check that R waits for the editor to be closed before further processing code. In some cases, a little command line program is used to start a larger application (like for Komodo Edit/IDE), or the program delegates to an existing instances and exits immediately, even if the file is still edited. Such editors are not recommended at all for file_edit().

If you want to use files that are compatibles between all platforms supported by R itself, you should think about using ASCII encoding as much as possible and the Windows style of line-ending. That way, you ensure that all the default editors will handle those files correctly, including the broken default editor on Windows, notepad, which does not understand at all MacOS or Unix line ending characters!

See Also

system_file(), file.path(), file.edit()

Examples

## Not run: 
# Create a template file in the tempdir...
template <- tempfile("template", fileext = ".txt")
cat("Example template file to be used with file_edit()", file = template)

# ... and edit a new file, starting from that template:
new_file <- tempfile("test", fileext = ".txt")
file_edit(new_file, template = template, wait = TRUE)

message("Your file contains:")
readLines(new_file)

# Eliminate both the file and template
unlink(new_file)
unlink(template)

## End(Not run)

svMisc documentation built on Oct. 12, 2021, 1:08 a.m.