SYNOPSIS

# Set a field in the leader
if marc_match('LDR/6','c')
marc_set('LDR/6','p')
end
# Set all the 650-p fields to 'test'
marc_set('650p','test')
# Set the 100-a subfield where indicator-1 is 3
marc_set('100[3]a','Farquhar family.')
# Copy data from another field in a subfield
marc_set('100a','$.my.deep.field')

DESCRIPTION

Read our Wiki pages at <https://github.com/LibreCat/Catmandu/wiki/Fixes> for a complete overview of the Fix language.