Extract word using sed

Shell Programming and Scripting
1

Hello,
I am new to sed and am trying to extract a word using sed.

for example i have a line "const TotalAmount& getTotalAmount() const; " in the file test.txt

I am trying to extract getTotalAmount() from the line.

For this i tried

cat test.txt | sed -n 's/.*get[a-zA-Z]*\(\)//p

But the output is

       () const;

Could you please let me know the correct expression or what i am doing wrong.

Also could you please suggest some good basic tutorials for Sed.

2

For extracting the getTotalAmount() from the string.You use the following command.

sed -r 's/.*(get[a-zA-Z]+\(\)).*/\1/g' <file>

This is the best tutorial for reading about SED.

SED and Regular Expressions

3

You try this.

echo "const TotalAmount& getTotalAmount() const;" | sed -r 's/.{19}//;s/.{7}$//'
4 
sed -r "s/.*(getTotalAmount\(\)).*/\1/g" file
5

Try this

 cat test | sed -nr 's/.*(get[a-zA-Z]*\(\)).*/\1/p'

Output

getTotalAmount()

I believe that this tutorial would be nice for beginners
Sed - An Introduction and Tutorial

6

Or you can try this also

sed -re 's/.{19}//;s/.{8}$//' test.txt

Here what I am doing is I am removing the first 19 characters and last 8 characters.
So you can easily get the middle remaining string as "getTotalAmount()".

7 
sed -n "s/.*\(get[a-zA-Z]*()\).*/\1/p" infile

grep -o "get[a-zA-Z]*()" infile
8

Using following way also you can get the getTotalAmount() from test.txt.

cat test.txt | cut -d ' ' -f 3

9

Thanks for the replies guys

The solution proposed by abubacker fits a lot my requirements
cat test | sed -nr 's/.*(get[a-zA-Z]*\(\)).*/\1/p'

Actually in the test.txt file I have more than one gets

for eg

asdasda getAmount() asdasda
adsadaa getTax() adasd

etc

Hence this expression matches exactly

Thanks a lot for the solutions.

---------- Post updated at 02:36 AM ---------- Previous update was at 02:32 AM ----------

I was looking to find a solution with grep, and this is a best option... -o

I just changed a bit to fit my requirements. I just added a get at the beginning.

grep -o "get[a-zA-Z]*()" test.txt