Accept existing copyright years while using the current year for header fixes

[jfdev001]

I'd like to check and format copyright headers without deriving copyright years from Git history. Enabling Git history attributes is too slow for our repository, and we do not need to verify the historical accuracy of the year.

Desired behavior

• If the header matches the configured format and contains a four-digit year (e.g., copyright header could accept patterns like 20[0-9]{2}), accept it unchanged, regardless of whether it matches the current year.
• If the header is missing, insert the configured header using the current year. So something like attrs.current_year, independent of Git history.
• If a recognizable header is malformed, such as having incorrect spacing, replace it with the configured header using the current year.
• Preserve unrelated comments and report conflicting copyright headers rather than overwriting them.

For example, assuming the current year is 2026, this valid header should remain unchanged:

/*
 * Copyright 2023 Example Company.
 */

But this malformed header:

/*
 *Copyright 2023 Example Company.
 */

should become:

/*
 * Copyright 2026 Example Company.
 */

Configuration

I'd like to keep Git-ignore handling enabled while disabling Git history attributes:

[git]
ignore = "enable"
file_attrs = "disable"

Is this possible with the existing configuration? If not, would you consider an optional feature that separates accepted copyright years from the year used when generating or repairing headers?

[tisonkun]

This is technically not easy. (Because hawkeye typically generate license header and do literal matches, rather than matching a regexp that would cause complicated edge cases)

But based on discussion on apache/skywalking#10223, typically you can just put the inception_year in your license header so that the whole setup becomes easier:

[header]
text = "Copyright {{ props.inception_year }} {{ props.copyright_owner }}."

[props]
copyright_owner = "Example Company"
inception_year = 2026