Lets have some fun with emacs rectangles. Lets assume you have the following text:
012345678901234567890123456789
val1 = 10;
val2 = 20;
val3 = 30;
Now, you need to add "(int)" in front of all the numbers. You can do it one line at a time, or you could use rectangles in emacs. Move the cursor to the start of 10, set mark, make the selection until start of 30. Hint: To set the mark, just hit Ctrl+Space and take your cursor to where you need to stop. Something like this,
012345678901234567890123456789
val1 = 10;
val2 = 20;
val3 = 30;
Ok, now lets insert the string using "string-insert-rectangle" and enter the string that we want to be inserted, in our case "(int)"
M-x string-insert-rectangle
String insert rectangle (default void ): (int)
012345678901234567890123456789
val1 = (int)10;
val2 = (int)20;
val3 = (int)30;
Now, say you wanted to give a space between the (int) and the number. Mark the rectangle as show below:
012345678901234567890123456789
val1 = (int)10;
val2 = (int)20;
val3 = (int)30;
We will use the "open-rectangle" command now.
M-x open-rectangle
012345678901234567890123456789
val1 = (int) 10;
val2 = (int) 20;
val3 = (int) 30;
Cool, now let's delete the spaces in the front using "delete-rectangle". Make the rectangle and...
012345678901234567890123456789
val1 = (int) 10;
val2 = (int) 20;
val3 = (int) 30;
M-x delete-rectangle
012345678901234567890123456789
val1 = (int) 10;
val2 = (int) 20;
val3 = (int) 30;
Now, just for fun, we are going to cut a rectangle and yank it somewhere else. Lets remove 1,2,3 from the variable names and put them in the front (bad idea, I know). Lets select the rectangle and call the "kill-rectangle" command
012345678901234567890123456789
val1 = (int) 10;
val2 = (int) 20;
val3 = (int) 30;
M-x kill-rectangle
012345678901234567890123456789
|val = (int) 10;
val = (int) 20;
val = (int) 30;
Move the cursor (show above as | ) to where you want to yank the rectangle now (in our case, the beginning of the word) and run "yank-rectangle"
M-x yank-rectangle
012345678901234567890123456789
1val = (int) 10;
2val = (int) 20;
3val = (int) 30;
Now, of course there are key-binding available (its Emacs for heaven's sake, even if there is no key-binding you can make your own).
From the Emacs
manual
- C-x r k
- Kill the text of the region-rectangle, saving its contents as the
“last killed rectangle” (
kill-rectangle).
- C-x r d
- Delete the text of the region-rectangle (
delete-rectangle).
- C-x r y
- Yank the last killed rectangle with its upper left corner at point
(
yank-rectangle).
- C-x r o
- Insert blank space to fill the space of the region-rectangle
(
open-rectangle). This pushes the previous contents of the
region-rectangle to the right.
- C-x r N
- Insert line numbers along the left edge of the region-rectangle
(
rectangle-number-lines). This pushes the previous contents of
the region-rectangle to the right.
- C-x r c
- Clear the region-rectangle by replacing all of its contents with spaces
(
clear-rectangle).
- M-x delete-whitespace-rectangle
- Delete whitespace in each of the lines on the specified rectangle,
starting from the left edge column of the rectangle.
- C-x r t string
- Replace rectangle contents with string on each line
(
string-rectangle).
- M-x string-insert-rectangle string
- Insert string on each line of the rectangle.
Enjoy!
