github.com/benhoyt/goawk@v1.8.1/testdata/gawk/gsubtst4.ok (about) 1 input 12345 2 output gsub(/regex/,"x",input) 3 4 regex output 5 (^) x12345 6 ($) 12345x 7 (^)|($) x12345x 8 ($)|(^) x12345x 9 (2) 1x345 10 (^)|2 x1x345 11 2|(^) x1x345 12 ($)|2 1x345x 13 2|($) 1x345x 14 (2)|(^) x1x345 15 (^)|(2) x1x345 16 (2)|($) 1x345x 17 ($)|(2) 1x345x 18 .((2)|(^)) x345 19 .((^)|(2)) x345 20 .((2)|($)) x34x 21 .(($)|(2)) x34x 22 x{0}((2)|(^)) x1x345 23 x{0}((^)|(2)) x1x345 24 x{0}((2)|($)) 1x345x 25 x{0}(($)|(2)) 1x345x 26 x*((2)|(^)) x1x345 27 x*((^)|(2)) x1x345 28 x*((2)|($)) 1x345x 29 x*(($)|(2)) 1x345x 30 x{0}^ x12345 31 x{0}$ 12345x 32 (x{0}^)|2 x1x345 33 (x{0}$)|2 1x345x