Shell Programming and Scripting

I am having a text file "test.txt" tht contains name & Ip address as below,
Name|IP address
xxx|10.10.10.10
yyy|20.20.20.20

I need to extract only IP address field:
Ur reply was :
cat test.txt | awk '{print $1}'

Ur code gave me all the fields like below:
Name|IP address
xxx|10.10.10.10
yyy|20.20.20.20

But i need like below:
IP address
10.10.10.10
20.20.20.20

This should help you..

Code:

$ cat temp | cut -d "|" -f2
10.101.10
30.30.30

The use of cat is redundant:

Code:

< test.txt cut -d "|" -f2

or:

Code:

cut -d "|" -f2 < test.txt

Regards

Or if you prefer awk after all

Code:

awk -F '|' '{print $1}' test.txt

The cat is useless in all these cases.

While it is indeed true that the use of the "cat" command in a proposed solution like:

Code:

cat temp | cut -d "|" -f2

is not necessary, that command is more easily readable and understandable than the program solutions of:

Code:

< test.txt cut -d "|" -f2
cut -d "|" -f2 < test.txt

All comes down to what the goal is of a proposed solution and code. The first example is easy to read, can be followed and understood by all.
In addition, when the 'next person' must follow our programs, it is much easier to understand well-written code where everything is explicit.
IMHO

You don't even need the redirection.

Code:

cut -d "|" -f2 test.txt

This thread is not the time or the place for an in-depth discussion of the Useless topic, though.

Well I think the most important thing here is to give a simple solution first to the person who has posted the question.

Improvements/enhancements would come in later.Useless use of cat could be considered only when there would a performance issue of the script.

Also as rightly said by joeg, the statement using cat is easier to read, and all the statements in the script should be easily readble unless there is a specific requuirement to complicate the code for performance issues or otherwise.

I hope pooppp got all the answers he wanted, and it would left upto him to choose a perfect soultion.

Thanks!
nua7