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Grep on a list

 
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# 1  
Old 01-18-2015
Grep on a list
Hi,

If I have a list called list.txt and on each line theres a string of the form something*blah, how do I remove everything after the * for each item? Thanks!
# 2  
Old 01-18-2015
Hello jyu429,

Welcome to forums, kindly use code tags for commands/codes/Inputs used by you in the posts as per forum rules. Now for your requirement please do let us know the complete input and expected output for same, it will help us to advise you, based on some assumptions following you can take as a start up.

Lets say we have following input file.
Code:
cat test1
ABSCDET something*bla sdheufhkrm349875  eruhg38t jqd7842r
AJBUWEBDEK something*bla r3jgf743yt4in 34uf3984 u4hf9843y

Then following is the code for same, which may help.
Code:
awk '{gsub(/\*.*/,"*",$0);print}'  test1

Output will be as follows.
Code:
ABSCDET something*
AJBUWEBDEK something*

Thanks,
R. Singh
# 3  
Old 01-18-2015
Or sed:
Code:
sed 's/*.*/*/' file

To also remove the asterisk:
Code:
sed 's/*.*//' file

or
Code:
cut -d\* -f1 file

Last edited by Scrutinizer; 01-18-2015 at 10:41 AM..
# 4  
Old 01-18-2015
A literal * should be quoted in an RE
Code:
sed 's/\*.*//'

# 5  
Old 01-18-2015
Quote:
Originally Posted by MadeInGermany
A literal * should be quoted in an RE
Code:
sed 's/\*.*//'

Not if it is the first character...

Code:
*
The <asterisk> shall be special except when used:
In a bracket expression

As the first character of an entire BRE (after an initial '^', if any)

As the first character of a subexpression (after an initial '^', if any);

9.3.3 BRE Special Characters
# 6  
Old 01-18-2015
There are many old sed out there...
An escaped * is good style. And safe.
# 7  
Old 01-18-2015
It is part of to the POSIX specification. And so this will work fine with those older and compliant seds (and even seds that are older than that) .... So the assertion in #3 is inaccurate and I do not share this "good style and safe" opinion. It is immediately clear that the first asterisk cannot be anything other than literal, unless one assumes a mistake, which is not the case..
Last edited by Scrutinizer; 01-19-2015 at 12:17 AM..
 
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