The AwkSyntax structure

The AwkSyntax structure implements the AWK syntax for regular expressions. The syntax is defined on pp. 28-30 of The AWK Programming Language, by Aho, Kernighan and Weinberger. The syntax has been extended with interval syntax, which was added as part of the POSIX standard.


structure AwkSyntax : REGEXP_PARSER


The meta characters are: "\" "^" "$" "." "[" "]" "|" "(" ")" "*" "+" "?"

Atomic REs:
  c	matches the character c (for non-metacharacters c)
  "^"	matches the empty string at the beginning of a line
    "$"	matches the empty string at the end of a line
  "."	matches any single character (except \000 and \n)
Escape sequences:
    "\b"	matches backspace
    "\f"	matches formfeed
    "\n"	matches newline (linefeed)
    "\r"	matches carriage return
    "\t"	matches tab
    "\"ddd	matches the character with octal code ddd.
    "\"c	matches the character c (e.g., \\ for \, \" for ")
  "\x"dd  matches the character with hex code dd.
Character classes:
    [...]	matches any character in "..."
    [^...]	a complemented character list, which matches any character not
     in the list "..."
Compound regular expressions, where A and B are REs:
    A|B	matches A or B
    AB	matches A followed by B
    A?	matches zero or one As
    A*	matches zero or more As
    A+	matches one or more As
    A{n}	matches n copies of A
    A{n,}	matches n copies of A
    A{n,m}	matches n copies of A
    (A)	matches A