string

Match literal string; see #%literal

bytes

Match literal byte string; see #%literal

pat pat

Match concatenation of matches; see #%juxtapose

pat ++ pat

Match concatenation of matches

(pat)

Same as pat

[charset]

Match any in charset; see #%brackets

pat || pat

Match either pat

pat *

Zero or more repetitions of pat

pat +

One or more repetitions of pat

pat ?

Zero or one matches of pat

pat {min .. max}

min to max-1 repetitions of pat; see #%comp

pat {min ..= max}

min to max repetitions of pat; see #%comp

.

Any non-newline character

any

Any character

char

Like any, but implies string mode

byte

Like any, but implies byte-string mode

bof

Beginning of input (i.e., “file”)

eof

End of input (i.e., “file”)

bol

Beginning of a line

eol

End of a line

$ id: pat

Capture group, set id to match for pat

$ id

Backreference, match same as id

$ int

Backreference, match same as int

$ expr

Splice: match pattern produced by expr

~~ pat

Anonymous capture group match pat

lookahead(pat)

Match empty if pat matches after

lookbehind(pat)

Match empty if pat matches before

! lookahead(pat)

Match empty if pat does not match after

! lookbehind(pat)

Match empty if pat does match before

word_boundary

Match empty outside of word

word_continue

Match empty within word

if tst | pat | pat

Condition on lookahead, lookbehind, or backreference

cut

Match empty, but limit backtracking

string: pat

Specify string mode, match pat

bytes: pat

Specify byte-string mode, match pat

case_sensitive: pat

Match pat case-sensitively

case_insensitive: pat

Match pat case-insensitively

alpha

ASCII letters a-z and A-Z

upper

ASCII uppercase letters A-Z

lower

ASCII lowercase letters a-z

digit

ASCII digits 0-9

xdigit

Hexadecimal digits 0-9, a-f, and A-F

alnum

alpha plus digit

word

alnum plus _

newline

Newline (ASCI 10)

blank

Space (ASCI 32) and tab (ASCI 7)

space

Newline (10), return (13), space (32), tab (7), and form feed (12)

graph

ASCII characters that print with ink

print

graph plus space

cntrl

ASCII control character(ASCII 0 through 31)

ascii

ASCII characters (ASCII 0 through 127)

latin1

Latin-1 characters (Unicode 0 through 255)

unicode.Ll

Character in a Unicode general category Ll

unicode.cat

Character in other Unicode general category...

string

All characters in string

bytes

All bytes in bytes

(charset)

Same as charset

charset charset

Union of charsets; see #%juxtapose

charset - charset

Inclusive range between single-element charsets

charset || charset

Union of charsets

charset && charset

Intersection of charsets

charset -- charset

Difference of charsets

! charset

Inverse of charset

any

All characters