Of course..

cat your_original_fasta_file

# This will output the content of your file allowing the use of the next pipes or "|"

You need to take into consideration that every fasta file has always 4 separated lanes

paste - - - -

will join the 4 lanes in a single lane. This will facilitate the using of awk in the next lane as not carriage returns or number of lanes need to be considered after this step. This is a nice trick indeed learned from this forum

You can define in awk the input file separator. You do it by allowing awk to define a variable (-v) and the kind of separator. It is likely you can define the OFS separator within clauses without requiring the using of -v, though. OFS stands for Output Field Separator, and "\t" means that this separator will be a tab.

Then you need to figure out the whole fasta content in a single lane with each of the items separated to each other with a tab

Then you ask awk to print items $1 (the name), $4 (the sequence), the character "+", and finally $8 (the quality lane). In this case, it is essential to write a colon "," among every variable because this way awk includes a tab separating each of the items.

Items $2 and $3 are the *1 or *2 and the lenght=???? items. You can figure out why I needed to use $8

The fourth lane in a fastq file needs the "+" character, but nothing else to date. Sometimes you make a multiGb fastq file substantially smaller by erasing the extra content of this fourth lane

The last lane is a "tr" usual unix code that replaces each of the tab file ("\t") for a carriage return character ("\n"). This recomposed the original fastq file

The last command starting with the > is easy to understand. It writes your file with the modified content