Regular Expressions 101

Explanation

Pro

Non-Capturing Group(?:(?!\/\/).*[ \t]*\"\${distro_id}:\${distro_codename}-security\";)

Negative Lookahead(?!\/\/)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

.*any character (except for line terminators), repeated any number of times

Character Class[ \t]*

*matches any number of characters from the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

\ta tab character (ASCII 9)

\"the literal " (34₁₀ / 42₈ / 22₁₆)

\$the literal $ (36₁₀ / 44₈ / 24₁₆)

{distro_id}:the literal text {distro_id}: (case sensitive)

\$the literal $ (36₁₀ / 44₈ / 24₁₆)

{distro_codename}-securitythe literal text {distro_codename}-security (case sensitive)

\"the literal " (34₁₀ / 42₈ / 22₁₆)

;the literal ; (59₁₀ / 73₈ / 3B₁₆)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

26 tokens

Regular Expression

(?:(?!\/\/).*[ \t]*\"\${distro_id}:\${distro_codename}-security\";)

New

Unattended-Upgrade::Allowed-Origins {
    "${distro_id}:${distro_codename}";
    "${distro_id}:${distro_codename}-security";
//  "${distro_id}:${distro_codename}-updates";
//  "${distro_id}:${distro_codename}-proposed";
//  "${distro_id}:${distro_codename}-backports";
};

Substitution

Unattended-Upgrade::Allowed-Origins {
    "${distro_id}:${distro_codename}";
    "${distro_id}:${distro_codename}-security";
//  "${distro_id}:${distro_codename}-updates";
//  "${distro_id}:${distro_codename}-proposed";
//  "${distro_id}:${distro_codename}-backports";
};