Off topic:id in text file for sequence retrival from multifasta

Question

[tcf.hcdg]

Dear all

I have a text file containing all the sequences which I wanted to extract from the fasta file. I tried as an example with some raw sequences using grep function and it works perfectly

But I am facing some problem with the original file. I am getting the blank output file. I tried different way and found that there is a problem with the IDs which is in the text file.

Problem which I could understand until now "ids in the text file have the space character at the end" due to this space I am getting the blank output file.

I took some of the sequences from the ID file and remove the space at the end and run again the grep script. It gives me result.

I would like to know

1. Is space at the end of the id in the text file matter?
2. How can I remove the space from the id file with some command?
3. Is there some way that I can tell grep that do not consider the space at the end?

My code is

grep -A1 -wFf ID.txt input.fasta > result.fa

Thanks