http://people.csail.mit.edu/jaffer/Docupage/copyrights.html
	copyrights
	Current Version Released Terms 1.7 2003-02-01 GPL

The copyrights program searches through the given files looking for "copyright", "Copr.", "©", or "©" (followed by years and name of holder in either order). It also recognizes the phrase "public domain". For each file it reports each distinct copyright once.

Quick Start

• Obtain SCM Scheme Implementation.
• Obtain SLIB Scheme Library.
• Obtain copyrights.scm (6.kB) and install in PATH directory as "copyrights".

Usage

Usage: copyrights [-m NUM] [-n CNT] FILE1 FILE2 ...

  Displays at most NUM (default 10) of each FILE's copyrights occuring
  within the first CNT (default 1000) lines or groups of 100 chars.
  Returns 0 if a copyright is found; otherwise returns 1.

Usage: copyrights [-m NUM] [-n CNT] -
  As above, but reads filenames from standard input.

Examples

$ copyrights [oO]vertones.*
Overtones.html:59:Copyright 2003 Aubrey Jaffer</ADDRESS>
overtones.png:30:Copyright 2003 Aubrey Jaffer/z
overtones.ps:184:Copyright 2003 Aubrey Jaffer) show

$ copyrights AnaLugojana.*
AnaLugojana.abc:29:Copyright 1999 Voluntocracy.
AnaLugojana.mid:1:Copyright 1999 Voluntocracy.
AnaLugojana.pdf:

$ copyrights sharpbang.c
sharpbang.c:2:   This program is in the public domain.

Further Development

This first release of copyrights is a simple proof of concept. The list of desired improvements is so extensive that the next program need not reuse anything in the current version.

• Each copyright instance should be scored; and the user able to specify thresholds for detection.
• Misspellings of key words should be recognized and ranked with a lower score.
• Two-digit years (98) should be recognized and scored depending on the presence of 4-digit years in the same instance.
• Copyright years are usually given in numerical order; if an instance is scrambled, its score should be lowered.
• Copyright years are usually given either before the holder name or after the holder name, but not both places. Instances should be scored accordingly.
• The user should be able to specify year ranges to be penalized in scoring.
• The user should be able to specify that high quality copyright instances of particular holders not be reported.
• For copyright instances with specified holders, and on the basis of dates in CVS/Entries, the program should be able to report which files lack a copyright year for the date they were last modified.
• Loic Dachary suggests a grep-like -v option to report those files lacking a copyright. I suggest that the user also be able to specify a file size minimum for signaling this.
• There is a large collection of software licenses in http://www.gnu.org/philosophy/license-list.html. The copyrights program should be able to scan for the presence of a license immediately following the copyright instance; and identify the close (and closest) matches among the GNU license collection.

Nearly every aspect of the future program incorporating these improvements is approximate. The steady progress of genomics matching algorithms lets us find close matches in linear time and space (some titles tease about sub-linear times).

The SLIB function diff:edit-length returns the edit distance between tokenized word sequences; and should be usable for license matching. Dynamic-programming the copyright instance search can likely do the rest (or see Curriculum Vitae: Gene Myers for approximate pattern matching algorithms).

Histocomputability is computation modeled on biological immune function. In this paradigm copyright is the Major Histocompatibility Complex presented by nearly every cell (data file) type in an individual organism (software package). The copyrights program assumes the function of CD4 and CD8 T-cells in recognizing self and non-self copyrights.