re = /(\d{4}.\d{3}.\d{3}) (\S+) (\S+) (\S+) (\S+) (\S+)\n(.+)\nHS\.code: (\S+) Country of origin: (\S+)\nEAN: (\S+)/m
str = '"11 4149.310.025 000 1 37,78 1 37,78
PISTON
HS.code: 87084099 Country of origin: EU/DE
EAN: 2050000141478
21 0734.401.251 000 4 3,05 1 12,20
PISTON RING
HS.code: 73182100 Country of origin: JP
EAN: 2050000026638"'
subst = ': $1 $2 $3 $4 $5 $6 $7 $8 $9 $10\\n'
result = str.gsub(re, subst)
# Print the result of the substitution
puts result
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html