github.com/benhoyt/goawk@v1.8.1/testdata/gawk/gsubtst3.in (about)

     1  (^)             12345           x12345
     2  ($)             12345           12345x
     3  (^)|($)         12345           x12345x
     4  ($)|(^)         12345           x12345x
     5  2               12345           1x345
     6  (^)|2           12345           x1x345
     7  2|(^)           12345           x1x345
     8  ($)|2           12345           1x345x
     9  2|($)           12345           1x345x
    10  (2)|(^)         12345           x1x345
    11  (^)|(2)         12345           x1x345
    12  (2)|($)         12345           1x345x
    13  ($)|(2)         12345           1x345x
    14  ((2)|(^)).      12345           xx45
    15  ((^)|(2)).      12345           xx45
    16  .((2)|($))      12345           x34x
    17  .(($)|(2))      12345           x34x
    18  (^)|6           12345           x12345
    19  6|(^)           12345           x12345
    20  ($)|6           12345           12345x
    21  6|($)           12345           12345x
    22  2|6|(^)         12345           x1x345
    23  2|(^)|6         12345           x1x345
    24  6|2|(^)         12345           x1x345
    25  6|(^)|2         12345           x1x345
    26  (^)|6|2         12345           x1x345
    27  (^)|2|6         12345           x1x345
    28  2|6|($)         12345           1x345x
    29  2|($)|6         12345           1x345x
    30  6|2|($)         12345           1x345x
    31  6|($)|2         12345           1x345x
    32  ($)|6|2         12345           1x345x
    33  ($)|2|6         12345           1x345x
    34  2|4|(^)         12345           x1x3x5
    35  2|(^)|4         12345           x1x3x5
    36  4|2|(^)         12345           x1x3x5
    37  4|(^)|2         12345           x1x3x5
    38  (^)|4|2         12345           x1x3x5
    39  (^)|2|4         12345           x1x3x5
    40  2|4|($)         12345           1x3x5x
    41  2|($)|4         12345           1x3x5x
    42  4|2|($)         12345           1x3x5x
    43  4|($)|2         12345           1x3x5x
    44  ($)|4|2         12345           1x3x5x
    45  ($)|2|4         12345           1x3x5x
    46  x{0}((2)|(^))   12345           x1x345
    47  x{0}((^)|(2))   12345           x1x345
    48  x{0}((2)|($))   12345           1x345x
    49  x{0}(($)|(2))   12345           1x345x
    50  x*((2)|(^))     12345           x1x345
    51  x*((^)|(2))     12345           x1x345
    52  x*((2)|($))     12345           1x345x
    53  x*(($)|(2))     12345           1x345x
    54  x{0}^           12345           x12345
    55  x{0}$           12345           12345x
    56  (x{0}^)|2       12345           x1x345
    57  (x{0}$)|2       12345           1x345x