Insert Text which is Read from the Line Above

jlb333333 has asked for the wisdom of the Perl Monks concerning the following question:

I have a text file that looks something like this:

A21  103  
A22  103  
A23  103  
A25  103  
A26  103  
A27  103  
12.3     7.3     .0289     179     2     5     1     4     3     1    
+ 0     0     0
A28  103  
 4.5     4.2     .0000     479     1     0     0     0     0     0    
+ 0     0     0
10.2     9.6     .0188     250     2     5     0     4     2     3    
+ 0     0     0
10.2     9.6     .0188     250     2     5     0     4     2     3    
+ 0     0     0
A29  103  
 4.5     4.2     .0000     479     1     0     0     0     0     0    
+ 0     0     0
10.2     9.6     .0188     250     2     5     0     4     2     3    
+ 0     0     0
A30  103  
A32  103  
 4.5     4.2     .0000     479     1     0     0     0     0     0    
+ 0     0     0
10.2     9.6     .0188     250     2     5     0     4     2     3    
+ 0     0     0
A33  103  
 4.5     4.2     .0000     479     1     0     0     0     0     0    
+ 0     0     0
10.2     9.6     .0188     250     2     5     0     4     2     3    
+ 0     0     0
A34  103  
A36  103  
 4.5     4.2     .0000     479     1     0     0     0     0     0    
+ 0     0     0
[download]

The data is separated by tabs or spaces

I wish to be able to read in the file, remove the lines with two batches of text(eg.'A21 103') unless they are followed by a longer line of data(eg.'12.3 7.3 .0289'...).

If they are followed by a longer line of data, to read the two batches of text and insert them at the beginning of the subsequent longer lines until the next short batch is found. And so on through the file.

In this example, I want the output therefore to look like this:

A27  103  12.3     7.3     .0289     179     2     5     1     4     3
+     1     0     0     0  
A28  103   4.5     4.2     .0000     479     1     0     0     0     0
+     0     0     0     0
A28  103  10.2     9.6     .0188     250     2     5     0     4     2
+     3     0     0     0
A28  103  10.2     9.6     .0188     250     2     5     0     4     2
+     3     0     0     0
A29  103    4.5    4.2     .0000     479     1     0     0     0     0
+     0     0     0     0
A29  103  10.2    9.6      .0188     250     2     5     0     4     2
+     3     0     0     0
A32  103   4.5     4.2     .0000     479     1     0     0     0     0
+     0     0     0     0
A32  103  10.2     9.6     .0188     250     2     5     0     4     2
+     3     0     0     0
A33  103   4.5     4.2     .0000     479     1     0     0     0     0
+     0     0     0     0
A33  103  10.2     9.6     .0188     250     2     5     0     4     2
+     3     0     0     0
A36  103   4.5     4.2     .0000     479     1     0     0     0     0
+     0     0     0     0
[download]

The data lines may be in batches of one, two, three, four or even five lines before the short line which is actually a kind of a heading for the data that follows below it.

(The 'headings' without 'data' below them are not required and need to be dropped from the output, as stated above.)

I cannot find a way to do this.

I have googled a lot for examples but without any success. Hope someone can teach me how to do this.

Thank you very much for your help.

Comment on Insert Text which is Read from the Line Above Select or Download Code

Replies are listed 'Best First'.
Re: Insert Text which is Read from the Line Above by NetWallah (Canon) on Feb 26, 2016 at 20:15 UTC
`perl -ane "@F<3 and @hdr=@F,next; print qq\|@hdr $_\|" data1.txt` [download] Change to single quotes for Linux. "Think of how stupid the average person is, and realize half of them are stupider than that." - George Carlin	[reply] [d/l]
Re^2: Insert Text which is Read from the Line Above by ExReg (Priest) on Feb 26, 2016 at 20:54 UTC
And that is why I love Perl! I'd give you my whole days worth of ++ if I had more left. A pure work of art!	[reply]
Re^2: Insert Text which is Read from the Line Above by jlb333333 (Novice) on Feb 27, 2016 at 08:15 UTC
Hi NetWallah. That is absolutely amazing. As I am part of the below average person group you will have to help me with one further question. I managed to capture the output through running the command on Explorer^2's DOS Command line option. I pasted the output into a text file and all my checks so far on your output after running the code on a 2600 line input file have found the output to be 100% correct. However, I need to capture the output in a more easy way. How do I insert this code into a .pl file? Do I need 'if ($line =~ ........' etc. If you can give me some idea on that it will help me so much for this particular program and many more in the future. Many, many, many thanks.	[reply]
Re^3: Insert Text which is Read from the Line Above by poj (Abbot) on Feb 27, 2016 at 08:42 UTC
#!perl use strict; my $infile = $ARGV[0]; my $outfile = $ARGV[1]; unless (@ARGV==2) { die "Usage : perl $0 infile outfile\n" }; open IN, '<',$infile or die "Could not open $infile : $!\n"; open OUT,'>',$outfile or die "Could not open $outfile : $!\n"; my @hdr; my $count_in; my $count_out; while (<IN>){ ++$count_in; my @f = split; if (@f<3){ @hdr = @f; } else { print OUT "@hdr $_"; ++$count_out; } } print "$count_in lines read from $infile\n"; print "$count_out lines written to $outfile\n"; close IN; close OUT; [download] poj	[reply] [d/l]
Re^4: Insert Text which is Read from the Line Above by jlb333333 (Novice) on Feb 27, 2016 at 10:28 UTC
Re^5: Insert Text which is Read from the Line Above by poj (Abbot) on Feb 27, 2016 at 10:34 UTC
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