There are other options to the
vi command that can be
You can open a file directly to a specific line number or pattern.
You can also open a file in read-only mode.
Another option recovers all changes to a file that you were
editing when the system crashed.
When you begin editing an existing file, you can call the file in and then move to the first occurrence of a pattern or to a specific line number. You can also specify your first movement by search or by line number right on the command line:
Opens file at line number n.
Opens file at last line.
Opens file at the first occurrence of pattern.
In the file practice, to open the file and advance directly to the line containing the word Screen, enter:
With a screen editor you can scroll the page, move the cursor, delete lines, and insert characters, while seeing the results of your edits as you make them. Screen editors are very popular, since they allow you to make changes as you read
If you include spaces in the pattern, you must enclose the whole pattern within single or double quotes:
or escape the space with a backslash:
In addition, if you want to use the general pattern-matching syntax described in Chapter 6, Global Replacement , you may need to protect one or more special characters from interpretation by the shell with either single quotes or backslashes.
+/pattern is helpful
if you have to leave an editing session in the
middle. You can mark your place by inserting a pattern
HERE. Then when you return to the
file, all you have to remember is
NOTE: Normally, when you're editing in vi, the
wrapscanoption is enabled. If you've customized your environment so that
wrapscanis always disabled, you might not be able to use
+/pattern. If you try to open a file this way, vi opens the file at the last line and displays the message "Address search hit BOTTOM without matching pattern."
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:
view command, like the
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
If you have a problem writing out the file, see the problem checklists summarized in Appendix D, Problem Checklist .
Occasionally there is a system failure while you are editing a file.
Ordinarily, any edits made after your last write (save) are lost.
However, there is an option,
-r, which lets you
recover the edited buffer at the time of a system crash.
When you first log on after the system is running again, you will receive a mail message stating that your buffer has been saved.
In addition, if you type the command:
you will get a list of any files that the system has saved.
with a file name to recover the edited buffer.
For example, to recover the edited buffer of the file
practice after a system crash, enter:
vi -r practice
It is wise to recover the file immediately, lest you inadvertently make edits to the file, and then have to resolve a version skew between the preserved buffer and the newly edited file.
You can force the system to preserve your buffer even when there is
not a crash by using the command
You may find it useful
if you have made edits to a file, then discover that you can't save
your edits because you don't have write permission. (You could also
just write a copy of the file out under another name or into a directory
where you do have write permission. See the section "Problems
Saving Files" in Chapter 1, The vi Text Editor.)