PowerShell: Regular Expressions

powershell_regular_expressions.ps1

#Requires -Version 5.1
# Reference: 1) https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_regular_expressions
# Reference: 2) https://docs.microsoft.com/en-us/dotnet/standard/base-types/regular-expression-language-quick-reference

$TestEmailFrom = @(
    "smokey.bear@usda.gov"
    "  smokey.bear@usda.gov    "
    "<smokey.bear@usda.gov>"
    " <  smokey.bear@usda.gov  > "
    "Smokey Bear <smokey.bear@usda.gov>"
    "Smokey Bear smokey.bear@usda.gov"
    "Smokey Bear <smokey+fire@usda.gov>"
    "Bear <bear@usda.gov>"
    "Bear<bear@usda.gov>"
    "Bear <  bear@usda.gov >  "
    "Smokey's Bear <smokey's.bear@usda.gov>"
    "Smokey's Bear-Owl <smokey's.bear-owl@usda.gov>"
    "S. Bear <s.bear@usda.gov>"
    "S.S Bear <s.s.bear@usda-home.gov>"
    "Smokey Bear <smokey-w-bear@usda.gov>"
    "  Smokey   Bear    <smokey-w-bear@usda.gov>"
)

# Example 1: E-mail address validation and parsing
# Adapted from https://www.emailregex.com to add subaddressing tag
$EmailAddressRegex = @(
    "^\s*"                                                  # BOL
    "(?<LocalPart>\w+(?:[._\-']\w+)*)+"                     # local-part
    "(?:\+(?<Tag>\w+(?:[._\-']\w+)*))?"                     # subaddressing tag
    "@(?<Domain>(?:\w+(?:[-.]\w+)*)+\.(?:\w{2,}))"          # domain
    "\s*$"                                                  # EOL
)

# Example 2: E-mail From (name and address) validation and parsing
$EmailFromRegex = @(
    "^\s*"                                                  # BOL
    "(?:(?<FirstName>\w+(?:[.\-'][\s\w]+?)*?)\s*"           # first name
    "(?<LastName>\w+(?:[.\-'][\s\w]+?)*?)?\s*)??"           # last name
    "<?\s*?(?<LocalPart>\w+(?:[._\-']\w+)*)+"               # local-part
    "(?:\+(?<Tag>\w+(?:[._\-']\w+)*))?"                     # subaddressing tag
    "@(?<Domain>(?:\w+(?:[-.]\w+)*)+\.(?:\w{2,}))+\s*?>?"   # domain
    "\s*$"                                                  # EOL
)

# Example 3: Phone number validation and parsing, North American Numbering Plan
# Adapted from Francis Gagnon at https://stackoverflow.com/questions/16699007/regular-expression-to-match-standard-10-digit-phone-number
$PhoneNanpRegex = @(
    "^\s*"                                                  # BOL
    "(?:\+?(?<CountryCode>\d{1,3}))?[-. (]*"                # country code
    "(?<AreaCode>\d{3})[-. )]*"                             # area code
    "(?<Prefix>\d{3})[-. ]*"                                # central office code/prefix
    "(?<LineNumber>\d{4})"                                  # line number
    "(?: *x(?<Extension>\d+))?"                             # extension
    "\s*$"                                                  # EOL
)

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