---
name: "Image::ExifTool::BuildTagLookup"
section: "3pm"
platform: "linux"
package: "perl-image-exiftool"
version: "13.55-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Image::ExifTool::BuildTagLookup"
---

# Image::ExifTool::BuildTagLookup(3pm)

Build ExifTool tag lookup tables

## NAME

Image::ExifTool::BuildTagLookup - Build ExifTool tag lookup tables

## DESCRIPTION

This module is used to generate the tag lookup tables in Image::ExifTool::TagLookup.pm and tag name documentation in Image::ExifTool::TagNames.pod, as well as HTML tag name documentation.  It is used before each new ExifTool release to update the lookup tables and documentation, but it is not used otherwise.  It also performs some validation and consistency checks on the tag tables.

## SYNOPSIS

```
  use Image::ExifTool::BuildTagLookup;
  $builder = Image::ExifTool::BuildTagLookup->new;
  # update Image::ExifTool::TagLookup
  $ok = $builder->WriteTagLookup('lib/Image/ExifTool/TagLookup.pm');
  # update the tag name documentation
  $ok = $builder->WriteTagNames('lib/Image/ExifTool/TagNames.pod','html');
  # print some statistics
  my $count = $$builder{COUNT};
  foreach (sort keys %$count) {
      printf "%5d %s\n", $$count{$_}, $_;
  }
```

## MEMBER VARIABLES

- PRESERVE\_DATE

  Flag to preserve "Last revised" date in HTML files.  Set before calling **WriteTagNames()**.

- COUNT

  Reference to hash containing counting statistics.  Keys are the descriptions, and values are the numerical counts.  Valid after BuildTagLookup object is created, but additional statistics are added by **WriteTagNames()**.

- WRITE\_PSEUDO

  Returned list of writable pseudo tags.

## AUTHOR

Copyright 2003-2026, Phil Harvey (philharvey66 at gmail.com)

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

## SEE ALSO

[**Image::ExifTool**(3pm)](/Image::ExifTool/3pm.md), [**Image::ExifTool::TagLookup**(3pm)](/Image::ExifTool::TagLookup/3pm.md), [**Image::ExifTool::TagNames**(3pm)](/Image::ExifTool::TagNames/3pm.md)