Modifying commands

del: Delete header ID/description and/or attributes
set: Replace the header, header attributes or sequence with new content
trim: Trim sequences on the left and/or right (single range) or extract and concatenate several ranges
mask: Soft or hard mask sequence ranges
upper: Convert sequences to uppercase
lower: Convert sequences to lowercase
revcomp: Reverse complements DNA or RNA sequences
concat: Concatenates sequences/alignments from different files