Wildcard Patterns and Expressions - syntax reference

2022-05-18

Note: This is a "quick reference". The instructions are subjectively reduced to a minimum, to keep focus and clarity.

Wildcard Patterns

• Special markers:

  • ? == any char
  • * == "" "any-chars"
  • a|b == a || b

• A match action will skip over ./ or ../ at start of string, to avoid an unexpected match with .* in file-path.

• A match action is case insensitive.

Wildcard Expressions

• Special markers:

  • ? == any char

  • * == "" "any-chars"

  • a|b == a || b

  • [abc] == a || b || c

  • []abc[] == a || b || c || [ || ]

  • [!abc] == ! [abc] <==> [^abc] alias

  • [!]abc[] == ! []abc[]

  • [a!^] == a || ! || ^

  • [a-c] == a || b || c

• Predefined classes:

  • \\s \\w \\d \\x [:s:] [:w:] [:d:] [:x:] == space word digit xdigit

  • \\S \\W \\D \\X [:S:] [:W:] [:D:] [:X:] == negated class

  • \\p \\P [:p:] [:P:] == Safe(r) Path chars, skip these chars:

    Ctrl SPC \" # $ % & \' ( ) * / : ; < > ? [ \\ ] { | } \`` DEL

  • (capture) == 1 occurrence <==> (1=capture) alias

  • (1=capture) == 1 occurrence

  • (?=capture) == 0..1 occurrences

  • (+=capture) == 1..n occurrences

  • (*=capture) == 0..n occurrences

  • (?-pattern) == non-capture variant, use - marker

  • (!-pattern) == negated match <==> (^=pattern) alias

  • (^-pattern) == negated match

• Anchors:

  • < == start of word
  • > == end of word
  • ^ == start of haystack/line
  • $ == end of haystack/line

• Escape other chars:

• \\x == when x is not in predefined classes and is not an anchor a case sensitive match for exactly this char is expected.

• A match action will skip over ./ or ../ at start of string, to avoid an unexpected match with .* in file-path.

• A match action is case insensitive.

Note that:

• Syntax allows expressions: *()* ?()? (1=?=) (1=*=) (1=1=)
• To negate something use at the beginning: ! or ^