Regular Expressions 101

Pro

^start of line

Negative Lookahead(?!.*opt3)

.*any character (except for line terminators), repeated any number of times

opt3the literal text opt3 (case sensitive)

.*any character (except for line terminators), repeated any number of times

Group 1(filename\.txt)

filenamethe literal text filename (case sensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

txtthe literal text txt (case sensitive)

Global pattern flags

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

Detailed match information will be displayed here automatically.

25 tokens

^(?!.*opt3).*(filename\.txt)

New

filename.txt  opt1 opt2 opt4
filename.txt  opt1 opt2 opt3 opt4
 filename.txt  opt1 opt2 opt4
  filename.txt  opt1 opt2 opt3 opt4

filename.txt  opt1 opt2 opt4
filename.txt  opt1 opt2 opt3 opt4
 filename.txt  opt1 opt2 opt4
  filename.txt  opt1 opt2 opt3 opt4