Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
Processing...

Test String

Code Generator

Language

Generated Code

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r"(?m)^@([^\s]+).+global\s+([^\s]+)\s+([^,]+).+").unwrap(); let string = "; ModuleID = 'foo.c' source_filename = \"foo.c\" target datalayout = \"e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128\" target triple = \"x86_64-pc-linux-gnu\" @Test = dso_local global i32 5, align 4 ; Function Attrs: noinline nounwind optnone uwtable define dso_local void @main() #0 { ret void } attributes #0 = { noinline nounwind optnone uwtable \"correctly-rounded-divide-sqrt-fp-math\"=\"false\" \"disable-tail-calls\"=\"false\" \"frame-pointer\"=\"all\" \"less-precise-fpmad\"=\"false\" \"min-legal-vector-width\"=\"0\" \"no-infs-fp-math\"=\"false\" \"no-jump-tables\"=\"false\" \"no-nans-fp-math\"=\"false\" \"no-signed-zeros-fp-math\"=\"false\" \"no-trapping-math\"=\"false\" \"stack-protector-buffer-size\"=\"8\" \"target-cpu\"=\"x86-64\" \"target-features\"=\"+cx8,+fxsr,+mmx,+sse,+sse2,+x87\" \"unsafe-fp-math\"=\"false\" \"use-soft-float\"=\"false\" } !llvm.module.flags = !{!0} !llvm.ident = !{!1} !0 = !{i32 1, !\"wchar_size\", i32 4} !1 = !{!\"clang version 10.0.0-4ubuntu1 \"} "; // result will be an iterator over tuples containing the start and end indices for each match in the string let result = regex.captures_iter(string); for mat in result { println!("{:?}", mat); } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Rust, please visit: https://docs.rs/regex/latest/regex/