re = /(\[img.*?\].*?photobucket.*?.jpg)(\[\/img.*?\])/i
str = 'Connecting rod fitted to prevent steering tie rod from cranking:
[url=http://s557.photobucket.com/user/realboss7669/media/F707F408-829F-48B9-9AED-BB57CEFF96C0_zpslwioah0z.jpg.html:jaeyh8wg][img:jaeyh8wg]http://i557.photobucket.com/albums/ss16/realboss7669/F707F408-829F-48B9-9AED-BB57CEFF96C0_zpslwioah0z.jpg[/img:jaeyh8wg][/url:jaeyh8wg]
From the rear:
[url=http://s557.photobucket.com/user/realboss7669/media/05AE0DB2-83FD-4B2C-9FDA-E3257DFEB832_zpsc6cfuqwi.jpg.html:jaeyh8wg][img:jaeyh8wg]http://i557.photobucket.com/albums/ss16/realboss7669/05AE0DB2-83FD-4B2C-9FDA-E3257DFEB832_zpsc6cfuqwi.jpg~original[/img:jaeyh8wg][/url:jaeyh8wg]
Steering damper mounts finished - without the connecting rod the damper would get bent:
[url=http://s557.photobucket.com/user/realboss7669/media/C85A0F5D-413D-4779-9F09-BD43BB798238_zpse8s6dxyu.jpg.html:jaeyh8wg][img:jaeyh8wg]http://i557.photobucket.com/albums/ss16/realboss7669/C85A0F5D-413D-4779-9F09-BD43BB798238_zpse8s6dxyu.jpg[/img:jaeyh8wg][/url:jaeyh8wg]
<!-- s8) --><img src="{SMILIES_PATH}/icon_cool.gif" alt="8)" title="Cool" /><!-- s8) -->'
subst = '$1~original$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