Login or Register to Ask a Question and Join Our Community


Shell Programming and Scripting

Grouping each 2 lines

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Grouping each 2 lines
# 1  
Old 09-18-2010
Question Grouping each 2 lines
Whats a good way to group (by adding a new integer to the front of each line) pairs of lines, such that lines 1 & 2 are group 1, lines 3 & 4 are group 2, etc...

ex input:
A
B
C
D
etc...

ex output:
1A
1B
2C
2D
etc...
# 2  
Old 09-19-2010
Hi

Code:
# cat a
A
B
C
D
E
# awk '{print i $0;}!(NR%2){i++}' i=1 a
1A
1B
2C
2D
3E
#

Guru.
This User Gave Thanks to guruprasadpr For This Post:
watingo
# 3  
Old 09-19-2010
loop through each line of the file using a counter variable but only increment the counter if the line count modulus 2 equals 0

here is a Perl example. you can port the logic to shell.


Code:
#!/usr/bin/perl

use strict;
use warnings;

my $counter=1;
my $line_count=0;

while(<DATA>) {
   print "${counter}$_";
   $counter++ if $line_count % 2;
   $line_count++;
}

__DATA__
A
B
C
D
E
F
G
H

# 4  
Old 09-19-2010
Code:
ruby -ne 'BEGIN{i=0};($.-1)%2==0 and i+=1; print "#{i} #{$_}"' file

# 5  
Old 09-19-2010
Code:
awk '{print int(NR/2+0.5) $0}' file

Last edited by rdcwayx; 09-19-2010 at 04:06 AM..
# 6  
Old 09-19-2010
Code:
awk '$0=int(i+=0.5)$0' i=0.5 file

Code:
awk 'sub(/^/,(NR%2)?++i:i)' file

Code:
awk '$0=((NR%2)?++i:i)$0' file

Code:
awk 'NR%2{++i}$0=i$0' file

Code:
awk '$0=(i+=NR%2)$0' file

Last edited by Scrutinizer; 09-19-2010 at 04:31 AM..
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Help with grouping and zipping

Hi can you please help with the below ? source file: Column1,Column2,Column3,Column4 abc,123,dir1/FXX/F19,1 abc,123,dir1/FXX/F20,1 abc,123,dir1/FXX/F23,2 abc,123,dir1/FXX/C25,2 abc,123,dir1/FXX/X25,2 abc,123,dir1/FXX/A23,3 abc,123,dir1/FXX/Z25,3 abc,123,dir1/FXX/Y25,4 I want to... (3 Replies)
Discussion started by: paul1234
3 Replies

2. Shell Programming and Scripting

Grouping and counting

Hello, I would like to group/sort a file of records by a particular field and then count how many records belong in that grouping. For example say I have the following data: 1234|"ZZZ"|"Date"|"1"|"Y"|"ABC"|""|AA ABCD|"ZZZ"|"Date"|"1"|"Y"|"ABC"|""|AA EFGH|"ZZZ"|"Date"|"1"|"Y"|"ABC"|""|BB... (14 Replies)
Discussion started by: Nik44
14 Replies

3. Shell Programming and Scripting

Name grouping

awk 'FNR==NR {a; next} $NF in a' genes.txt refseq_exons.txt > output.txt I can not figure out how to group the same name in $4 together. Basically, all the SKI together in separate rows and all the TGFB2. Thank you :). chr1 2160133 2161174 SKI chr1 218518675 218520389 TGFB2... (1 Reply)
Discussion started by: cmccabe
1 Replies

4. Shell Programming and Scripting

Grouping

Hi all, I am using following command: perl program.pl input.txt output.txt CUTOFF 3 > groups_3.txt containing program.pl, two files (input.txt, output.txt) and getting output in groups_3.txt: But, I wish to have 30 files corresponding to each CUTOFF ranging from 0 to 30 using the same... (1 Reply)
Discussion started by: bioinfo
1 Replies

5. Shell Programming and Scripting

regular expression grouping across multiple lines

cat book.txt book1 price 23 sku 1234 auth Bill book2 sku 1233 price 22 auth John book3 auth Frank price 24 book4 price 25 sku 129 auth Tod import re f = open('book.txt', 'r') text = f.read() f.close() m =... (2 Replies)
Discussion started by: chirish
2 Replies

6. Shell Programming and Scripting

Selective grouping

I have a text file in this format. Group: AAA Notes: IP : 11.11.11.11 #User xxxxxxxxx #Password aaaaaaaaaaaaaaaa Group: AAA Notes: IP : 11.11.11.22 #User yyyyyyyyyyyyy #Password bbbbbbbbbbbbb (8 Replies)
Discussion started by: anil510
8 Replies

7. UNIX for Dummies Questions & Answers

Grouping or appending the lines in a file through Unix

Hi, I am looking for a way to Group the Lines in a file.. Basically My file structure is something like this A 1 100 abc def A 1 200 abc def A 1 300 abc def A 2 100 pqr def A 2 200 pqr def A 2 300 pqr def A 1 100 abc def A 1 200 xyz def A 1 300 xyz def I need it as... (6 Replies)
Discussion started by: mkandula1983
6 Replies

8. Shell Programming and Scripting

Grouping or appending the lines in a file through Unix

Hi, I am looking for a way to Group the Lines in a file.. Basically My file structure is something like this A 1 100 abc def A 1 200 abc def A 1 300 abc def A 2 100 pqr def A 2 200 pqr def A 2 300 pqr def A 1 100 abc def A 1 200 xyz def A 1 300 xyz def I need it as... (1 Reply)
Discussion started by: mkandula1983
1 Replies

9. UNIX for Advanced & Expert Users

grouping lines

Hi all, I have input lines like below: A;100;Paris;City;10;0;0 A;100;Paris;City;0;10;0 A;100;Paris;City in Europe;0;0;20 B;101;London;City;20;0;0 B;101;London;City;0;20;0 B;101;London;City in Europe;0;0;40 I need to group the above lines to: A;100;Paris;City in Europe;10;10;20... (4 Replies)
Discussion started by: andy2000
4 Replies

10. UNIX for Advanced & Expert Users

Regarding the user grouping

I am new to the unix server. My question is: i have 10 users a b c d e f g h i j Among the 10 5 users are (normal) user and remainging 5 users are (qad) users How can i sepearte this one? How can i give the dlc access rights? Please provide the clear cut idea. (0 Replies)
Discussion started by: kingganesh04
0 Replies
Login or Register to Ask a Question