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Old 11-29-2007, 11:02 AM   #1
senthilvael
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Unhappy Command to separate 2nd line's 3rd word from a text file


HI,
Please suggest me the command in linux to separate second line's 3rd word from a text file.
 
Old 11-29-2007, 11:09 AM   #2
matthewg42
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awk would be ideal.
 
Old 11-29-2007, 02:33 PM   #3
pixellany
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Code:
cat filename |sed -n '2p'|cut -d " " -nf 3
Assumes that words are delimited by exactly one space. If more than one space, add another sed to replace N spaces with one.

Not tested:

Code:
sed '/ */ /g'
 
Old 11-29-2007, 02:45 PM   #4
matthewg42
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Code:
awk 'NR==2 { print $3 ; exit }'
 
Old 11-29-2007, 09:03 PM   #5
pixellany
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Quote:
Originally Posted by matthewg42 View Post
Code:
awk 'NR==2 { print $3 ; exit }'
I'll match that and raise you one.... Next thing--someone will pop in with the PERL solution.
 
Old 11-29-2007, 09:53 PM   #6
Slokunshialgo
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Want some Perl?

Code:
#!/usr/bin/perl

$file = `cat $ARGV[0]`;
@lines = split(/\n/, $file);
$line = @lines[1];
$line =~ s/^([^ ]+[ ]+[^ ]+[ ]+)([^ ]+)([ ]+.*)/$2/;
print $line;
No idea if it'll work or not, and I know it's probably highly inefficient, but it's Perl.

EDIT: Somebody pointed out I got the wrong word

Last edited by Slokunshialgo; 11-29-2007 at 10:08 PM.
 
Old 11-29-2007, 11:31 PM   #7
jschiwal
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Quote:
Originally Posted by pixellany View Post
Code:
cat filename |sed -n '2p'|cut -d " " -nf 3
Assumes that words are delimited by exactly one space. If more than one space, add another sed to replace N spaces with one.

Not tested:

Code:
sed '/ */ /g'
Please stop doing that!
Use the form:
"sed -n '2p' filename |"

instead of
"cat filename | sed '/ */ /g' |"

There is absolutely no reason to use cat before sed or awk unless you want to add line numbers, or are using zcat with a compressed file.

IMHO, awk would be the best tool:
awk 'NR==2{ print $3 }' filename

No cat, only one program used, and extra white space is handled automatically.

Using perl would be overkill given the size of the perl shell. Sort of like going to the corner store in your Sherman tank instead of your sedan.

---

Yikes, looking back on the previous messages, I forgot the exit. Shame on me!

Last edited by jschiwal; 11-29-2007 at 11:38 PM.
 
Old 11-29-2007, 11:36 PM   #8
pixellany
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I'm trying to work on my reputation as a consistent offender in the unnecessary use of cat.....

Seriously, I do that because it's sometimes easier to explain what is happening. If I'm actually writing a script, I will be more efficient---I promise!!
 
  


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