vi/comp.editors/regexp

From sjreeves@eng.auburn.edu (Stan Reeves)
Subject: Regular Expression Question
Date: 12 Aug 92 12:54:06 GMT


I need to construct a regular expression that locates all words without
an "@".  I've exhausted all my own ideas and was wondering if I could
draw on the expertise of this group.


--
Stan Reeves
Auburn University, Department of Electrical Engineering, Auburn, AL  36849
INTERNET: sjreeves@eng.auburn.edu


From lwv26@cas.org (Larry W. Virden)
Subject: Re: Regular Expression Question
Reply-To: lvirden@cas.org (Larry W. Virden)
Date: Thu, 13 Aug 1992 11:52:27 GMT

In article <sjreeves.920812075405@eng.auburn.edu> sjreeves@eng.auburn.edu (Stan Reeves) writes:
:
:I need to construct a regular expression that locates all words without
:an "@".  I've exhausted all my own ideas and was wondering if I could
:draw on the expertise of this group.

Easy I thought, and I typed vi /etc/motd to play.

First, I tried:

/\<[^@]+\>

which is the most obvious thing.  And I got an error.  Oh, vi doesn't appear
to recognize +.  Sigh.  Well, let's try the next most obvious:

/\<[^@]*\>

That will do it, right?  Nah.  The problem here is that the * eats everything
up to the first @ in the line and treats it all as a string.

/\<[^.,<>!@#$%^&*()_-+=|\\{}:;"'~` 	]*\>

is close - there may be a few more things that I missed in there, and
there may be a need to quote a couple of those characters.  I gave up
after finding a subset of the above that worked enough to show me the
theory is right...
-- 
Larry W. Virden                 UUCP: osu-cis!chemabs!lvirden
Same Mbox: BITNET: lvirden@cas  INET: lvirden@cas.org
Personal: 674 Falls Place,   Reynoldsburg, OH 43068-1614
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From navarra@casbah.acns.nwu.edu (John Navarra)
Subject: Deleting text above and below PATTERN recursively
Date: Sat, 11 Jul 1992 00:04:36 GMT


	I want to do some recursive file manipulations using either vi
or ed under the following scenario:
	I have a file the contains a certain pattern which occurs at the
beginning of a line multiple times in a file. I want to delete 5 lines
above that pattern and 6 lines below that pattern for each occurance of
PATTERN in the file. I need some help writing a recursive routine to do
this. I started with the following ed script to do the first occurance:

/^PATTERN	#search for first occurance of PATTERN at begin of line 
-5n		#go up five lines
.,+4d		#delete from current line down 4 lines
.+1p		#print current line (skip the line matching PATTERN)
.,+5d		#delete from current line down 5 lines
w		#write it. 
q		#quit editing. 

Now I need some way to recursively search for PATTERN and give the 
neccessary 'q' for ed to complete the operations when no more PATTERNS
have been found.	
	I would love to see a solution in vi as well. 
Any ideas?

 
here is an idea of what the file would look like:
 
1
2
3		5 lines to be deleted
4
5
PATTERN TO MATCH
1
2
3
4		6 lines to be deleted
5
6
more text of file which does not need to be deleted
1
2
3
4
5
PATTERN TO MATCH
1
2
3
4
5
6

Thanx for any help,
-tms



From hansm@cs.kun.nl (Hans Mulder)
Subject: Re: Deleting text above and below PATTERN recursively
Date: Sat, 11 Jul 1992 03:39:36 GMT

In <1992Jul11.000436.15556@news.acns.nwu.edu> navarra@casbah.acns.nwu.edu (John Navarra) writes:
>	I want to do some recursive file manipulations using either vi
>or ed under the following scenario:

Is there any particular reason you insist on doing it recursively?

>	I have a file the contains a certain pattern which occurs at the
>beginning of a line multiple times in a file. I want to delete 5 lines
>above that pattern and 6 lines below that pattern for each occurance of
>PATTERN in the file. I need some help writing a recursive routine to do
>this. I started with the following ed script to do the first occurance:

>/^PATTERN	#search for first occurance of PATTERN at begin of line 
>-5n		#go up five lines
>.,+4d		#delete from current line down 4 lines
>.+1p		#print current line (skip the line matching PATTERN)

Which is it?  Do you want to print the line containing PATTERN, or do
you want to skip it?

>.,+5d		#delete from current line down 5 lines

In the paragraph above you said 6.

>w		#write it. 
>q		#quit editing. 

If I can assume that there are enough line above the first and below the
last occurance of PATTERN and that you wanted to skip the matching lines,
and that you meant 6 rather than 5, a vi/ex command to do it would be:

:g/^PATTERN/-5,-1d|+1,+6d

If on the other hand there might be occurances of PATTERN in the first or the
last 5 lines, and you do want those matching lines printed, you'd do:

:6,$-6g/^PATTERN/-5,-1d|p|+1,+6d

Or, if you insist on minimizing the number of keystrokes:

:6,$-6g/^PATTERN/-5,-dp|+,+6d


I'm afraid you can't do it in a single command in ed, you'll have to use two:

g/^PATTERN/-5,-d
g/^PATTERN/+,+6d

Add a 'p' to the first of these lines if you want to print the matching line.
Stick '6,$-6' in front if occurances of PATTERN near the extremes of the file
are a problem.

>	I would love to see a solution in vi as well. 

If you insist on doing it recursively and using true vi mode commands:

:write				" just in case... :-}
:set nowrapscan report=7	" so vi won't say "5 lines deleted"
:map K n5k5ddj6ddK+		" the + stops vi from saying "No tail recursion"
/^PATTERN/
1GK
:unmap K			" too dangerous to keep it around
:set wrapscan report=5

When you've typed the 1GK bit, vi will move around a lot and eventually
report: "Address search hit BOTTOM without matching pattern".  Ignore that.

--
Hope this helps,

Hans Mulder			hansm@cs.kun.nl


From dattier@ddsw1.mcs.com (David W. Tamkin)
Subject: Re: Deleting text above and below PATTERN recursively
Date: Sun, 12 Jul 1992 02:39:31 GMT
                the poster and does not represent MCSNet or the system owners.

navarra@casbah.acns.nwu.edu (John Navarra) wrote in
<1992Jul11.205053.29328@news.acns.nwu.edu>:

| 	I tried to put this in my .exrc file with the line:
| 
| :map ^Tp :g/^PATTERN/-5,-1d|+1,+6d
| 
| and I got the error "No lines in buffer" when starting up vi. A ^Tp
| only printed: :g/^PATTERN/-5,-1d
| 
| what happened?

Just as the pipe is a separator in an ex command, it is a separator in .exrc.
You told your .exrc to do TWO things with that line:

1.  to :map ^Tp :g/^PATTERN/-5,-1d

and 

2.  to +1,+6d

Accordingly it mapped ^Tp as you told it and tried to delete the six lines
below the current one, but there were no lines in the buffer when vi sourced
.exrc, so it couldn't do the second part.

The only way to include pipes in mappings is to precede them with a hard ^V;
that is, when you prepare your .exrc you have to type ctrl-V twice to get a
ctrl-V to stay in the file.

For a mapping like this one, which gets rescanned, one hard ^V should be
enough, since on the second scan you *want* the pipe to be interpreted as a
command separator.  Sometimes it takes three, five, or even seven hard ^V's
in a mapping in .exrc to get some problem characters like a pipe or the ^M
that will eventually become a ^J sufficiently quoted.

By the way, since you are mapping an ex command, you'll need a newline at the
end, so you have to put ^M (typed as ctrl-V ctrl-M) [or ^V^M (typed as three
ctrl-V's and a ctrl-M) or even ^V^V^V^M] on the end of that mapping, or when
you use it, the cursor will sit at the end of the command window at the
bottom of the vi screen and the commands in the mapping won't execute until
you send NL manually.

David W. Tamkin   Box 59297   Northtown Station, Illinois  60659-0297
dattier@ddsw1.mcs.com    CompuServe: 73720,1570    MCI Mail: 426-1818


From navarra@casbah.acns.nwu.edu (John Navarra)
Subject: Re: Deleting text above and below PATTERN recursively
Date: Sat, 11 Jul 1992 20:50:53 GMT

In article <1992Jul11.033936.10152@sci.kun.nl> hansm@cs.kun.nl (Hans Mulder) writes:
>In <1992Jul11.000436.15556@news.acns.nwu.edu> navarra@casbah.acns.nwu.edu (John Navarra) writes:
>
>>/^PATTERN	#search for first occurance of PATTERN at begin of line 
>>-5n		#go up five lines
>>.,+4d		#delete from current line down 4 lines
>>.+1p		#print current line (skip the line matching PATTERN)
>
>Which is it?  Do you want to print the line containing PATTERN, or do
>you want to skip it?

	This will skip the line by printing it. 

>
>>.,+5d		#delete from current line down 5 lines
>
>In the paragraph above you said 6.
	
	The way ed does this is by deleting the current line AND 5 more
additional lines ==6 lines. That is what I wanted to do. If you notice
the line '.,+4d' , this does the same thing and deletes 5 lines above
the pattern. 
 
>
>If I can assume that there are enough line above the first and below the
>last occurance of PATTERN and that you wanted to skip the matching lines,
>and that you meant 6 rather than 5, a vi/ex command to do it would be:
>
>:g/^PATTERN/-5,-1d|+1,+6d
>
	Yes, this is perfect. I didn't know you could do this in vi. I
do not need any recursion if a global search and replace option is 
available. I didn't know about the '|' in vi. 

btw, 
	I tried to put this in my .exrc file with the line:

:map ^Tp :g/^PATTERN/-5,-1d|+1,+6d

and I got the error "No lines in buffer" when starting up vi. A ^Tp
only