UNIX for Dummies Questions & Answers

for file in /source_dir/*.fasta
do
        fname="${file##*/}"
        awk '/>/{sub(">","&"FILENAME"_");sub(/\.fasta/,x)}1' "$file" > /dest_dir/$fname"
done

for file in /source_dir/*.fasta
do
        fname="${file##*/}"
        awk '/>/{sub(">","&"FILENAME"_");sub(/\.fasta/,x)}1' "$file" > /dest_dir/$fname"
done

$ awk '/>/{sub(/\..*/,x,FILENAME);$0=FILENAME"_"$2}1' FS=">" sample_1.fasta 

sample_1_node_1
atgatgatgat
sample_1_node_3
gtcgtcgtcgtcgtc
sample_1_node_12
gtagtagta