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delete line with conditions

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# 1  
Old 05-24-2011
delete line with conditions
Hi Dude,
I am struck up with another problem,Pls help me
I am new to perl , I have little knowledge only.

The scenario is
Code:
 
[abc:/def/ghi/jkl/mno]
 ssenthil = rw
 [abc:/def/ghi/jkl/mno/xyz]
 anilkg = rw
 [abc:/def/ghi/jkl/mno/pqr]
 @group1 = rw
 anilkg = rw
ssenthil = rw

i need output as below , I want to find "anilkg" and delete the preceding line that starts with "[" and ends with "]" . the condition is only one user is there. If there are any groups that start with "@" or any other user below the searching string should delete only the "searching string" and the output as below

Code:
 [abc:/def/ghi/jkl/mno]
 ssenthil = rw
 [abc:/def/ghi/jkl/mno/pqr]
 @group1 = rw
ssenthil = rw

will you pls suggest me?

Rgds
Anil.G

Moderator's Comments:
Mod Comment Please use [code] and [/code] tags when posting code, data or logs etc. to preserve formatting and enhance readability, thanks.
Last edited by zaxxon; 05-24-2011 at 07:05 AM.. Reason: code tags
# 2  
Old 05-24-2011
Lines don't start with '[' but with space in your examples.
# 3  
Old 05-24-2011
there are no spaces , the line either starts with alphabetic or "[" or "@"
# 4  
Old 05-24-2011
As i understand what you want, you can't be sure of the place of anilkg in a line it's not so easy because you must read 3 lines and delete line 1 and 2 only if line 3 begin with '[' and line 2 begin with anilkg.

So is it ok to do something like that ? :

1) Pass 1 : delete all lines with anilkg
2) Pass 2 : on the resulting output delete all line with '[' if next line also is '['

---------- Post updated at 12:21 PM ---------- Previous update was at 12:18 PM ----------

Quote:
Originally Posted by anil8103
there are no spaces , the line either starts with alphabetic or "[" or "@"
So please paste the real output that must be used, because the output on the first post have spaces at start of some lines.
# 5  
Old 05-24-2011
thats fine,, on the result delete the first line that starts with "[" and not the second line.

---------- Post updated at 03:59 PM ---------- Previous update was at 03:55 PM ----------

Input file

..........................................
[abc:/def/ghi/jkl/mno]
ssenthil = rw
[abc:/def/ghi/jkl/mno/xyz]
anilkg = rw

[abc:/def/ghi/jkl/mno/pqr]
@group1 = rw
anilkg = rw
ssenthil = rw
[abc:/def/ghi/jkl/mno/pqr]
@group1 = rw
ssenthil = rw

output

..............................................
[abc:/def/ghi/jkl/mno]
ssenthil = rw
[abc:/def/ghi/jkl/mno/pqr]
@group1 = rw
ssenthil = rw
[abc:/def/ghi/jkl/mno/pqr]
@group1 = rw
ssenthil = rw
# 6  
Old 05-24-2011
Hi,

Then i'll give a solution but not in perl.

Code:
sed "/anilkg/d" inputfilename | sed '$!N; /^\[.*\n\(\[.*\)/!P; D'

Now if you really need a perl solution it can be done also, but i don't have time do think about one now Smilie
# 7  
Old 05-24-2011
Hi,

This is what I understood, tell me if I'm wrong:

1.- Delete line found with user 'anilkg'.
2.- Delete previous line if the next one begins with '[' and ends with ']', or it is a blank line.
3.- Delete next line if it is blank.

Here you have a 'Perl' script with previous conditions:
Code:
$ cat script.pl
use strict;
use warnings;
use autodie;

@ARGV == 1 or die "Usage: perl $0 input-file\n";
open my $fh, "<", $ARGV[0];
my @prev_lines = ();
my $flag;

while ( <$fh> ) {
    chomp;
    if ( /^(?i:anilkg)/ ) {
        $flag = 1;
        next;
    } else {
        push @prev_lines, $_;
    }  

    if ( $flag && ( /^\[.*\]$/ || /^\s*$/ ) ) {
        pop @prev_lines;
        pop @prev_lines;
        push @prev_lines, $_ unless /^\s*$/;
    }  
    $flag = 0;
}

while ( @prev_lines ) {
    print +(shift @prev_lines), "\n";
}
$ perl script.pl infile
(Output suppressed).

Regards,
Birei
Last edited by birei; 05-24-2011 at 06:31 PM..
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