I believe fold command will take header into account too?
I wanna split a single-line multi-fasta (exclude >header) into 10 words/symbols per line multi-fasta file.
works on many *x systems, and should not have a problem with large files.
If there is a 2GB limit (happens if compiled with 32-bit and without largefile support), then it can help to let the shell open it (assuming the shell is either 64-bit or with largefile support).