Thank you so much this is useful however, If it is possible do not send the string in to a file, I need use one line to apply this fuction as I will use for loop to read A.txt file.
I am new to unix shell scripts. I have a file-A.txt which contained several names in "ABCo12345678.gz_to_ABCn12345678.gz" format. I want to extract the numbers in a "for" loop that means...