re = /(^[^-]+)-([^-]+)-/m
str = '12055371-1-Florence - BW Letter of Intent HB Comments 9-4-14-2.DOCX
12057668-2-EB-DUE-M- SBuxbaum FHA Benefit Plans-2.DOCX
12058210-1-Redline Letter of Intent-2.PDF
12058029-3-Florence Hospital--Order Establishing Bid Procedures-HB 9-23-14-2.DOCX
12058020-10-Florence - BW Letter of Intent 10,10,14 Revisions-2.DOCX '
subst = '\\1|\\2|'
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