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Old 01-18-2010, 01:27 AM   #1
mauludi
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How to delete/grab a line which matchs a pattern of a particular column only ?


Dear All,

I indeed need your help. It is very importan for my research work.

I have found many information about how to delete/grab a line in a text file including delete line with match a pattern but I did not find info about how to delete a line which match a pattern of a particular column only.

for example mydata.txt:
id type x y z
1 6 0.474611 0.227223 0.583947
2 4 0.422894 0.22726 0.536791
3 5 0.448963 0.200148 0.560336
4 3 0.386478 0.207721 0.515293
5 6 0.371617 0.22361 0.582206
6 4 0.32123 0.222999 0.534782


so how to obtain data with type 4 only so that mydata.text file become:

id type x y z
2 4 0.422894 0.22726 0.536791
6 4 0.32123 0.222999 0.534782

and how to have data without type 3 , mydata.test file become:

id type x y z

1 6 0.474611 0.227223 0.583947
2 4 0.422894 0.22726 0.536791
3 5 0.448963 0.200148 0.560336
5 6 0.371617 0.22361 0.582206
6 4 0.32123 0.222999 0.534782


thank a lot in advance

Mauludi
 
Old 01-18-2010, 01:32 AM   #2
Tinkster
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Hi, welcome to LQ!

awk is the perfect tool for this kind of job.

It allows you to compare regex against column type data (e.g.,
whitespace delimited text like yours).

Code:
awk '$2 ~ /4/' file > new_file
awk '$2 !~ /3/' file > new_file


Cheers,
Tink
 
Old 01-18-2010, 01:36 AM   #3
evo2
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Code:
awk '{ if ( $2==4 || FNR==1 ) print $0 }' mydata.text
This will print the first line or anyline when the 2nd column is 4.

Cheers,

Evo2.

Last edited by evo2; 01-18-2010 at 01:38 AM.
 
Old 01-18-2010, 02:13 AM   #4
mauludi
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Registered: Jan 2010
Posts: 21

Original Poster
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thank you for your quick reply,

but sorry for further question, how about obtain two type (for example 4 and 5) of my datafile.tx
id type x y z
1 6 0.474611 0.227223 0.583947
2 4 0.422894 0.22726 0.536791
3 5 0.448963 0.200148 0.560336
4 3 0.386478 0.207721 0.515293
5 6 0.371617 0.22361 0.582206
6 4 0.32123 0.222999 0.534782

so that it becomes :
2 4 0.422894 0.22726 0.536791
3 5 06 4 0.32123 0.222999 0.534782
6 4 0.32123 0.222999 0.534782

once agaiin thank you very much for your help
 
Old 01-18-2010, 02:33 AM   #5
evo2
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Code:
awk '{ if ( $2==4 || $2==5 || FNR==1 ) print $0 }' mydata.text
Evo2.
 
Old 01-18-2010, 12:07 PM   #6
Tinkster
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You just don't need either the "if" or the "print".

Code:
awk '$2==4 || $2==5 || FNR==1' mydata.text

Last edited by Tinkster; 01-18-2010 at 12:08 PM.
 
Old 01-18-2010, 06:52 PM   #7
evo2
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Quote:
Originally Posted by Tinkster View Post
You just don't need either the "if" or the "print".
Very true, but by including an example with them the OP will learn more.

Cheers,

EVo2.

Last edited by evo2; 01-18-2010 at 06:55 PM.
 
  


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