Fri, Nov 17, 2017 9:25 pm
Removing all lines containing a string in vi
To remove all lines containing a particular
string in the vi or
text editors, you can use the
g command to globally search for the
specified string and then, by putting a "d" at the end of the command line,
specify that you want all lines containing the specified string deleted. E.g.,
If I wanted to remove all lines containing the string "dog", I could use the
That command would also remove any lines containing "dogs", "dogged", etc.
If I just wanted to remove lines containing "dog", I could use
You can, of course, specify the pattern on which you wish to search using
regular expressions. E.g., if I wanted to remove any lines containing
either "dog" or "hog", I could use the command below.
By putting the leters "d" and "h" within
brackets, I indicate to vi that it should remove any
line that has either a "d" or an "h" followed by "og".
[ More Info ]
Tue, Jun 06, 2017 9:22 pm
Removing whitespace from lines in Vi
To remove whitespace characters, such as spaces and/or tabs from
a line while editing a file in the vi and
Vim text editor you can use a
regular expression (regexp) that incorporates
(lowercase letter "s"), which respresents a white space character. E.g.,
supposing the lines below appear in a file:
450 SN/GN Tech Edit Delete
ACE Edit Delete
ADO Edit Delete
AGO Edit Delete
AGS Edit Delete
AIM Edit Delete
ASF Edit Delete
I could hit the
colon key and type
s/\s*Edit Delete// to
delete the white space after the project name that appears at the
beginning of the line and the "Edit Delete" at the end of the line, so that
only the project name remains. To perform the substitution for all lines,
I could use
1,$ s/\s*Edit Delete//.
1,$ represents every line from the 1st to the last
1,$ s/old_pattern/new_pattern/ would indicate
that a substitution is to be performed on every line with new_pattern
replacing old_pattern on each line.
\s represents any whitespace character and the
after it indicates to look for zero or more occurrences of any whitespace
s/\s*Edit Delete// indicates to delete white
space characters followed by the words
I could also use
any non-alphanumeric character.
gVim Portable for Windows
Lesson 9: All this
RegexOne - Learn Regular Expressions with
simple, interactive exercises.
Sat, Feb 25, 2017 10:48 pm
Determining the differences between the current version and a vi swap file
When I attempted to edit a file, index.php, using the
vi editor, I saw
the following message:
Found a swap file by the name ".index.php.swp"
owned by: joe dated: Mon Feb 20 19:36:11 2017
file name: ~joe/www/UVNC/index.php
user name: joe host name: example.com
process ID: 19776
While opening file "index.php"
dated: Mon Feb 20 19:38:44 2017
NEWER than swap file!
(1) Another program may be editing the same file. If this is the case,
be careful not to end up with two different instances of the same
file when making changes. Quit, or continue with caution.
(2) An edit session for this file crashed.
If this is the case, use ":recover" or "vim -r index.php"
to recover the changes (see ":help recovery").
If you did this already, delete the swap file ".index.php.swp"
to avoid this message.
Swap file ".index.php.swp" already exists!
[O]pen Read-Only, (E)dit anyway, (R)ecover, (D)elete it, (Q)uit, (A)bort:
I hit the
q key to return to the
shell prompt. When I compared the time stamps on the current version of the
file and the .swp file, I saw that the current version had a time stamp 2
minutes after the time stamp for the .swp file.
$ ls -al | grep 'index.php'
-rw-rw-r--. 1 joe joe 7571 Feb 20 19:38 index.php
-rw-r--r--. 1 joe joe 20480 Feb 20 19:36 .index.php.swp
[ More Info ]
Fri, Jan 13, 2017 10:27 pm
Deleting up to a word or back to a word in the Vi or Vim editor
In the vi
text editor, you can delete all characters on a line up to a specified
word by placing the cursor on the line at the point where you wish to
start the deletion then hit the
key followed by the slash
key followed by the word up to which you wish to remove the characters
on the line. E.g., suppose you have the following line:
If you can force your heart and nerve and sinew To serve your turn long after they are gone, And so hold on when there is nothing in you Except the Will which says to them: “Hold on”;
From the poem
by Rudyard Kipling (1865-1936)
If you wished to delete all of the text on the line from the word "To" up
until, but not including the word "And" in "And so hold on...", while in command
mode, not insert mode, you could move the cursor to the "T" in "To" and then
hit the d key followed by the
forward slash key (
/) and then type
sure you use the matching capitalization). The line would then appear as shown
If you can force your heart and nerve and sinew And so hold on when there is nothing in you Except the Will which says to them: “Hold on”;
Suppose, instead, you had the cursor at the word "To" as before, but wanted
to delete backwards through the word "If", i.e., all the way to the beginning
of the line, instead. You could then hit the d key while in command
mode, then hit the question mark (
?) key and type
You would then have the text below.
To serve your turn long after they are gone, And so hold on when there is nothing in you Except the Will which says to them: “Hold on”;
For the backwards deletion, the word you type after the question mark is
included in the deletion. In this case, if you wished to delete
backwards to the beginning of the line, you could also have hit the
d key followed by the
? key and then hit the
^) key, which represents the beginning of the line. Likewise,
you could hit the dollar sign (
$) key to delete forward
to the end of the line, which it represents, or you could just hit the
D key, instead of the lower-case "d" to delete from the
current cursor position to the end of the line.
Mon, Aug 22, 2016 11:45 pm
Substituting characters for a matched regular expression in vi
is a screen-oriented text editor
for pattern matching and character substitution.
which stands for "Vi IMproved" is a clone of vi and recognizes similar
If you want to replace or insert characters at the beginning of a line,
the line beginning is represented by the
caret character, i.e.,
^ (Shift-6 on a standard computer keyboard), and line
endings are represented by the
dollar sign character,
E.g., the following quote has three occurences of the word "us". If I wanted
to replace only the "us" at the end of the line with "ourselves", I could hit
the colon key while not in vi's insert mode, which would give me a colon prompt
and then enter
s /us$/ourselves/ which would replace the occurence
of "us" at the end of the lne with "ourselves".
What lies behind us and what lies before us are tiny compared to what lies
~ Ralph Waldo Emerson
[ More Info ]
Wed, Dec 09, 2015 11:43 pm
Wrapping text and viewing the current line and column in the vi editor
If you use the vi
editors and wish to have lines automatically wrap to the next line
when you get close to the margin, i.e., the 80th column, rather
than having to hit the Return
key, you can use the
To enter the command, while not in input mode type
followed by the number you wish to use for the wrap margin.
The wrapmargin parameter is set to an integer number of characters. When set to
any nonzero number, vi will watch the lines that you type in the input modes.
When you get to within the "wraprmargin" number of characters of the 80th
character on the line, the next space character that you type will cause vi to
enter a carriage return for you. This parameter gives vi a word wrap
feature for entering text data. When set to zero, the wrap margin feature
Unix for Application Developers
by William A. Parrette ©1991, page 320
If you wish to have vi display the current line and column number as
you type, use
:set ruler. If it is turned on you will see the
current line number and column number displayed at the bottom of the vi window,
24,67 if you were on line 24 at column 67. The numbers
will change as you move the cursor whether you are in input mode or
not. You can turn it off with
Alternatively, you can also use control-G on a Mac OS X system or
Ctrl-G on a Linux system or with Vim on a Microsoft Windows
system, i.e., hit the control, or Ctrl, and G keys
simultaneously to see the current line and column numbers. You
will see something like the following displayed at the bottom of
"temp.txt" [Modified] line 30 of 34 --88%-- col 32
In the above example, while editing the file temp.txt the cursor
was on line 30 of the 34 lines in the file and was at column 32 when I
hit control-G. Since 30 is 88% of 34, the cursor was at a point 88
percent of the way through the file. Each time you hit control-G,
the status information will be displayed for the current line and column
when you hit the key combination.
With vi on a Mac OS X or Linux system, you can also use
!}fmt when not in input mode, to automatically wrap the text in
a paragraph so that a line doesn't exceed column 80 in that paragraph from the
point where you enter that command.
Wed, Oct 09, 2013 10:39 pm
Inserting text at the beginning and end of lines with vi's regexp
text editors support
the use of regular expressions
(abbreviated regex or regexp) for editing files.
In a regular expression
^ signifies the beginning of a line and
$ specifies the end of a line. To have an operation apply
to multiple lines at once, you can specify a range of lines, e.g.
16,25. To have the operation apply starting with the current
line, you can use a period,
., to represent the current line,
.,25 would mean apply the operation to the current line
and all subsequent lines up to and including line 25. Or you could specify
that the operation should be applied from the current line to the end of
the file by using
$ to represent the last line in the file,
Or you can have an operation apply to every line in a file
. E.g., the following line would insert
at the beginning of every line in a file.
s indicates a substitute operation will follow and the
/ delineate the pattern to be replaced and
the replacement pattern. In the above case, the
^ indicates the
beginning of the line and the replacement pattern is
When you are using
/ to delineate the patterns, it has a special
meaning and if you want to use it in a pattern you have to "escape" its
special meaning with an
escape character, which is the backslash,
E.g. to insert
</td> at the end of every line from the
current line to line 25, the following regular expression could be used:
Supposing that I wanted to put a
<td> at the beginning
of each line and a
</td> at the end of each line from the
current line through line 25. In that case I need to store the characters
in between the beginning and end of a line. You can specify text to be
stored by using parentheses,
( to mark the beginning of the
area on the line to be stored and
) to mark the end. Since a
., represents any character and an asterisk,
represents multiple occurrences,
^(.*)$ would store
all the characters on the line between the beginning and end of a line.
You must also "escape" the
) with the
backslash escape character as well. To reuse the characters you have stored
you recall them with
\1 ("1" is the number one). If you had
multiple occurrences of characters enclosed in parentheses, the second
instance could be recalled with
The line below would insert a <td> at the beginning of lines 16
through 25 and a </td> at the end of the lines.
If you wished to have the editor prompt you as to whether you wanted
the change made on a line, you could add a
/c option at the
end of the command to the editor. The command below would perform the same
action as the one above on every line from line 16 to the end of the file,
but would prompt you at each line as to whether the change should be made.
You would see each line highlighted one by one as you progressed through the
file with the following prompt each time.
replace with <td>\1<\/td> (y/n/a/q/l/^E/^Y)?
y would result in the replacement occurring whereas
n would result in the line remaining unchanged.
In this case, there is also a simpler means for inserting the table
tags at the beginning and end of each line as below:
.* represents the search pattern, which is every
character on the line. The ampersand,
&, also has a special
meaning; it is the text that matches the search pattern, so putting it between
the two tags results in all the text originally on the line remaining on
the line. The
/ at the end of the replacement pattern can be
eliminated if there is nothing following it such as a
Adding characters at the start and end of each line in a file
May 2, 2012
Search and replace
Vim Tips Wiki
Sat, Jun 27, 2009 12:04 pm
Reformatting a Paragraph in Vi
I often want to reformat a paragraph in Vi or Vim after I've pasted
information into a document when the text is wrapping around rather
than having line breaks at column 80. On a Linux system, I can place
the cursor at the beginning of the paragraph and use
to reformat the paragraph. But that doesn't work
when I'm using Vim
But I can use
at the beginning of the paragraph on a
Windows or Linux system to reformat a paragraph. When I then use the downward
arrow key to move down in the document, the paragraph reformats.
vim tips and tricks
Tue, Apr 14, 2009 9:39 pm
Inserting a Newline Character Using Vi
To insert a newline character, i.e. to create a new line in a file
using Vi on a Unix system, you can use
to actually type Ctrl-V
(i.e. the Ctrl
keys hit simultaneously) followed by Enter
to get the
to appear. For example, suppose that instead of commas separating elements
in a list you wish to put each element on a new line.
Gold, Silver, Bronze
You can use the following command in Vi to replace all commas
with the newline character starting from the first line in the file
to the last (represented by
As noted above, you need to hit Ctrl-V Enter to put the
^M in the command.
How to represent a new line character in a regex in VI?
Date: December 30, 2006
Sun, Apr 12, 2009 7:22 pm
How to Stop Vim from AutoIndenting in Files
I use Vim
for editing files on
Windows systems. I edit HTML files with it, but find its habit
of automatically indenting lines in those files based on the tags used
annoying rather than helpful. Fortunately, that behavior can be turned
off. To so so, edit the
file, which is in the
directory where you installed Vim, e.g.
For HTML files, i.e. any file with an extension of
, you can add the following two lines to stop the
autoindentation. Close Vim, add the lines, then reopen Vim and you should
no longer have the autoindenation in those files.
autocmd BufEnter *.html setlocal indentexpr=
autocmd BufEnter *.htm setlocal indentexpr=
You can enter similar lines to stop autoindentation in other files.
to stop auto indenting
Vim Tips Wiki
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