re = /\<(\d+)\>(\w+[\d\s\:]+\S+\s\S+\s(\d+)\s(\d+)\s(\d+)\s([\d\:\-\.\+\s]{0,30})\s+\d+)\s+(\d+)\s+(\S+)\s+(\S+\:.*?)(.*)/m
str = '<180>May 19 17:54:27 ise121 CISE_Internal_Operations_Diagnostics 0000046406 2 0 2015-05-19 17:54:27.930 +05:30 0000290168 34126 WARN System-Management: Remote syslog target is unavailable'
subst = ''
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