!the literal ! (3310 / 418 / 2116)
.*?any character (except for line terminators), repeated any number of times
.any character (except for line terminators)
Group 1(png|jpg|jpeg|bmp) pngthe literal text png (case sensitive) jpgthe literal text jpg (case sensitive) jpegthe literal text jpeg (case sensitive) bmpthe literal text bmp (case sensitive) Group 2(\|(thumbnail|(width=\d+,height=\d+)|(width=\d+)|(height=\d+)))? ?repeats the group contents below at most once:
\|the literal | (12410 / 1748 / 7C16)
Group 3(thumbnail|(width=\d+,height=\d+)|(width=\d+)|(height=\d+)) thumbnailthe literal text thumbnail (case sensitive) 2nd Alternative(width=\d+,height=\d+) Group 4(width=\d+,height=\d+) width=the literal text width= (case sensitive) \d+a digit, repeated at least once
,height=the literal text ,height= (case sensitive) \d+a digit, repeated at least once
3rd Alternative(width=\d+) width=the literal text width= (case sensitive) \d+a digit, repeated at least once
4th Alternative(height=\d+) height=the literal text height= (case sensitive) \d+a digit, repeated at least once
!the literal ! (3310 / 418 / 2116)
g modifier: global. Finds all matches instead of stopping after the first
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string