Add tag description option to exiv2 app

app/actions.cpp

@@ -498,6 +498,12 @@ bool Print::printMetadatum(const Exiv2::Metadatum& md, const Exiv2::Image* pImag
     first = false;
     std::cout << std::setw(30) << std::setfill(' ') << std::left << md.tagLabel();
   }
+  if (Params::instance().printItems_ & Params::prDesc) {
+    if (!first)
+      std::cout << " ";
+    first = false;
+    std::cout << std::setw(30) << std::setfill(' ') << std::left << md.tagDesc();
+  }
   if (Params::instance().printItems_ & Params::prType) {
     if (!first)
       std::cout << " ";

app/exiv2.cpp

@@ -283,14 +283,16 @@ void Params::help(std::ostream& os) const {
      << _("             X : Extract \"raw\" XMP\n")
      << _("   -P flgs Print flags for fine control of tag lists ('print' action):\n")
      << _("             E : Exif tags\n") << _("             I : IPTC tags\n") << _("             X : XMP tags\n")
-     << _("             x : Tag number (Exif and IPTC only)\n")
+     << _("             x : Tag number for Exif or IPTC tags (in hexadecimal)\n")
      << _("             g : Group name (e.g. Exif.Photo.UserComment, Photo)\n")
      << _("             k : Key (e.g. Exif.Photo.UserComment)\n")
      << _("             l : Tag label (e.g. Exif.Photo.UserComment, 'User comment')\n")
+     << _("             d : Tag description\n")
      << _("             n : Tag name (e.g. Exif.Photo.UserComment, UserComment)\n") << _("             y : Type\n")
-     << _("             c : Number of components (count)\n")
-     << _("             s : Size in bytes (Ascii and Comment types include NULL)\n")
-     << _("             v : Plain data value, untranslated (vanilla)\n")
+     << _("             y : Type\n") << _("             c : Number of components (count)\n")
+     << _("             s : Size in bytes of vanilla value (may include NULL)\n")
+     << _("             v : Plain data value of untranslated (vanilla)\n")
+     << _("             V : Plain data value, data type and the word 'set'\n")
      << _("             t : Interpreted (translated) human readable values\n")
      << _("             h : Hex dump of the data\n")
      << _("   -d tgt1  Delete target(s) for the 'delete' action. Possible targets are:\n")
@@ -720,6 +722,9 @@ int Params::evalPrintFlags(const std::string& optArg) {
           case 'V':
             printItems_ |= prSet | prKey | prType | prValue;
             break;
+          case 'd':
+            printItems_ |= prDesc;
+            break;
           default:
             std::cerr << progname() << ": " << _("Unrecognized print item") << " `" << i << "'\n";
             rc = 1;

app/exiv2app.hpp

@@ -151,7 +151,8 @@ class Params : public Util::Getopt {
     prValue = 256,
     prTrans = 512,
     prHex = 1024,
-    prSet = 2048
+    prSet = 2048,
+    prDesc = 4096
   };
 
   //! Enumerates common targets, bitmap

exiv2.md

@@ -566,34 +566,33 @@ as well as data columns included in the print output. Valid flags are:
 | g      | Group name (e.g., for Exif.Photo.UserComment, outputs Photo)                |
 | k      | Key (e.g., Exif.Photo.UserComment)                                          |
 | l      | Tag label (human-readable tagname, e.g., for Exif.Photo.UserComment, outputs 'User comment') |
-| n      | Tagname (e.g., for Exif.Photo.UserComment, outputs UserComment)             |
+| d      | Tag description                                                             |
+| n      | Tag name (e.g., for Exif.Photo.UserComment, outputs UserComment)             |
 | y      | Type (for available types, see [Exif/IPTC/XMP types](#exiv2_types))         |
 | c      | Number of components (for single entry types, the number of **sizeof('type')** in 'size'. For multi-entry types, the number of entries. See [Exif/IPTC/XMP types](#exiv2_types)) |
 | s      | Size in bytes of vanilla output (see note in [Exif 'Comment' values](#exif_comment_values)). Some types include a *NULL* character in the size (see [Exif/IPTC/XMP types](#exiv2_types)) |
 | v      | Plain data value (vanilla values, i.e., untranslated)                       |
-| V      | Plain data value, data type and the word 'set ' (see ['MODIFY' COMMANDS](#modify_cmds))|
+| V      | Plain data value, data type and the word 'set' (see ['MODIFY' COMMANDS](#modify_cmds))|
 | t      | Interpreted (translated) human-readable data values (includes plain vanilla values) |
 | h      | Hex dump of the data                                                        |
 
+**--Print** *flgs* can be combined with [--grep str](#grep_str) or 
+[--key key](#key_key) to further filter the output.
+
 <div id="Print_flgs_order">
 
-The order of the values in *flgs* is not respected. For example, the order 
-of the columns, using some tags from *Stonehenge.jpg*, is as follows:
+The order of the values in *flgs* is not respected and is output as follows:
 
-```
-$ curl --silent -O https://www.exiv2.org/Stonehenge.jpg
-$ exiv2 --Print xgknlycst Stonehenge.jpg
-```
+| Tag number<br>(x) | Plain 'set'<br>(V) | Group<br>(g) | Key<br>(k) | Tagname<br>(n) | Tagname label<br>(l) |Description<br>(d) | Type<br>(y) | Comp<br>(c) | Size<br>(s) | Value<br>(v) | Translated<br>(t) |
+|:------            |:----               |:------       |:------     |:------         |:------               |:------            |:------      |:------      |:------      |:---          |:------            |
 
-| Tag number<br>(x) | Plain 'set'<br>(V) | Group<br>(g) | Key<br>(k)                 | Tagname<br>(n) | Tagname label<br>(l) | Type<br>(y) | Comp<br>(c) | Size<br>(s) | Value<br>(E, I, X, v, t) | Translated<br>(t) |
-|:------            |:----               |:------       |:------                     |:------         |:------               |:------      |:------      |:------      |:------                   |:------           |
-| 0x0110            | set                | Image        | Exif.Image.Model           | Model          | Model                | Ascii       | 12          | 12          | NIKON D5300              | NIKON D5300      |
-| 0x0006            | set                | NikonIi      | Exif.NikonIi.ISO2          | ISO2           | ISO 2                | Byte        | 1           | 1           | 72                       | 200              |
-| 0x0000            | set                | xmp          | Xmp.xmp.Rating             | Rating         | Rating               | XmpText     | 1           | 1           | 0                        | 0                |
-| 0x0000            | set                | dc           | Xmp.dc.Family              | Family         | Family               | XmpBag      | 1           | 5           | Robin                    | Robin            |
+For example,
 
-**--Print** *flgs* can be combined with [--grep str](#grep_str) or 
-[--key key](#key_key) to further filter the output.
+```bash
+$ curl --silent -O https://www.exiv2.org/Stonehenge.jpg
+$ exiv2 --Print xVgknldycsvt -K Exif.Nikon3.Quality Stonehenge.jpg
+0x0004 set Nikon3       Exif.Nikon3.Quality                          Quality                     Quality                        Image quality setting          Ascii       8   8  NORMAL   NORMAL
+```
 
 <div id="delete_tgt1">
 

include/exiv2/datasets.hpp

@@ -280,6 +280,7 @@ class EXIV2API IptcKey : public Key {
   [[nodiscard]] std::string groupName() const override;
   [[nodiscard]] std::string tagName() const override;
   [[nodiscard]] std::string tagLabel() const override;
+  [[nodiscard]] std::string tagDesc() const override;
   [[nodiscard]] uint16_t tag() const override;
   [[nodiscard]] UniquePtr clone() const;
   //! Return the name of the record

include/exiv2/exif.hpp

@@ -140,6 +140,7 @@ class EXIV2API Exifdatum : public Metadatum {
   [[nodiscard]] std::string groupName() const override;
   [[nodiscard]] std::string tagName() const override;
   [[nodiscard]] std::string tagLabel() const override;
+  [[nodiscard]] std::string tagDesc() const override;
   [[nodiscard]] uint16_t tag() const override;
   //! Return the IFD id as an integer. (Do not use, this is meant for library internal use.)
   [[nodiscard]] int ifdId() const;

include/exiv2/iptc.hpp

@@ -113,6 +113,7 @@ class EXIV2API Iptcdatum : public Metadatum {
    */
   [[nodiscard]] std::string tagName() const override;
   [[nodiscard]] std::string tagLabel() const override;
+  [[nodiscard]] std::string tagDesc() const override;
   //! Return the tag (aka dataset) number
   [[nodiscard]] uint16_t tag() const override;
   [[nodiscard]] TypeId typeId() const override;

include/exiv2/metadatum.hpp

@@ -52,6 +52,8 @@ class EXIV2API Key {
   [[nodiscard]] virtual std::string tagName() const = 0;
   //! Return a label for the tag
   [[nodiscard]] virtual std::string tagLabel() const = 0;
+  //! Return a description for the tag
+  [[nodiscard]] virtual std::string tagDesc() const = 0;
   //! Return the tag number
   [[nodiscard]] virtual uint16_t tag() const = 0;
   /*!
@@ -181,6 +183,8 @@ class EXIV2API Metadatum {
   [[nodiscard]] virtual std::string tagName() const = 0;
   //! Return a label for the tag
   [[nodiscard]] virtual std::string tagLabel() const = 0;
+  //! Return a description for the tag
+  [[nodiscard]] virtual std::string tagDesc() const = 0;
   //! Return the tag
   [[nodiscard]] virtual uint16_t tag() const = 0;
   //! Return the type id of the value

include/exiv2/properties.hpp

@@ -262,6 +262,7 @@ class EXIV2API XmpKey : public Key {
   [[nodiscard]] std::string groupName() const override;
   [[nodiscard]] std::string tagName() const override;
   [[nodiscard]] std::string tagLabel() const override;
+  [[nodiscard]] std::string tagDesc() const override;
   //! Properties don't have a tag number. Return 0.
   [[nodiscard]] uint16_t tag() const override;
 

include/exiv2/tags.hpp

@@ -161,8 +161,7 @@ class EXIV2API ExifKey : public Key {
   [[nodiscard]] std::string tagName() const override;
   [[nodiscard]] uint16_t tag() const override;
   [[nodiscard]] std::string tagLabel() const override;
-  //! Return the tag description.
-  [[nodiscard]] std::string tagDesc() const;  // Todo: should be in the base class
+  [[nodiscard]] std::string tagDesc() const override;
   //! Return the default type id for this tag.
   [[nodiscard]] TypeId defaultTypeId() const;  // Todo: should be in the base class
 

include/exiv2/xmp_exiv2.hpp

@@ -108,6 +108,7 @@ class EXIV2API Xmpdatum : public Metadatum {
   //! Return the property name.
   [[nodiscard]] std::string tagName() const override;
   [[nodiscard]] std::string tagLabel() const override;
+  [[nodiscard]] std::string tagDesc() const override;
   //! Properties don't have a tag number. Return 0.
   [[nodiscard]] uint16_t tag() const override;
   [[nodiscard]] TypeId typeId() const override;

src/datasets.cpp

@@ -531,6 +531,10 @@ std::string IptcKey::tagLabel() const {
   return IptcDataSets::dataSetTitle(tag_, record_);
 }
 
+std::string IptcKey::tagDesc() const {
+  return IptcDataSets::dataSetDesc(tag_, record_);
+}
+
 uint16_t IptcKey::tag() const {
   return tag_;
 }

src/exif.cpp

@@ -292,6 +292,10 @@ std::string Exifdatum::tagLabel() const {
   return key_ ? key_->tagLabel() : "";
 }
 
+std::string Exifdatum::tagDesc() const {
+  return key_ ? key_->tagDesc() : "";
+}
+
 uint16_t Exifdatum::tag() const {
   return key_ ? key_->tag() : 0xffff;
 }

src/iptc.cpp

@@ -101,6 +101,10 @@ std::string Iptcdatum::tagLabel() const {
   return key_ ? key_->tagLabel() : "";
 }
 
+std::string Iptcdatum::tagDesc() const {
+  return key_ ? key_->tagDesc() : "";
+}
+
 uint16_t Iptcdatum::tag() const {
   return key_ ? key_->tag() : 0;
 }

src/properties.cpp

@@ -5139,6 +5139,13 @@ std::string XmpKey::tagLabel() const {
   return pt;
 }
 
+std::string XmpKey::tagDesc() const {
+  const char* pt = XmpProperties::propertyDesc(*this);
+  if (!pt)
+    return "";
+  return pt;
+}
+
 uint16_t XmpKey::tag() const {
   return 0;
 }

src/xmp.cpp

@@ -326,6 +326,10 @@ std::string Xmpdatum::tagLabel() const {
   return p_->key_ ? p_->key_->tagLabel() : "";
 }
 
+std::string Xmpdatum::tagDesc() const {
+  return p_->key_ ? p_->key_->tagDesc() : "";
+}
+
 uint16_t Xmpdatum::tag() const {
   return p_->key_ ? p_->key_->tag() : 0;
 }

test/data/test_reference_files/exiv2-test.out

@@ -90,15 +90,18 @@ Options:
              E : Exif tags
              I : IPTC tags
              X : XMP tags
-             x : Tag number (Exif and IPTC only)
+             x : Tag number for Exif or IPTC tags (in hexadecimal)
              g : Group name (e.g. Exif.Photo.UserComment, Photo)
              k : Key (e.g. Exif.Photo.UserComment)
              l : Tag label (e.g. Exif.Photo.UserComment, 'User comment')
+             d : Tag description
              n : Tag name (e.g. Exif.Photo.UserComment, UserComment)
              y : Type
+             y : Type
              c : Number of components (count)
-             s : Size in bytes (Ascii and Comment types include NULL)
-             v : Plain data value, untranslated (vanilla)
+             s : Size in bytes of vanilla value (may include NULL)
+             v : Plain data value of untranslated (vanilla)
+             V : Plain data value, data type and the word 'set'
              t : Interpreted (translated) human readable values
              h : Hex dump of the data
    -d tgt1  Delete target(s) for the 'delete' action. Possible targets are:

tests/bash_tests/test_pr_2279.py

@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+
+import system_tests
+
+class TestExifIPTCXmpTagOutput(metaclass=system_tests.CaseMeta):
+    url = "https://github.com/Exiv2/exiv2/pull/2279"
+
+    # Test the exiv2 application's `--Print` command
+    filename = "$data_path/Stonehenge.exv"
+    commands = ["$exiv2 --Print xVgknldycsvt --key Exif.Image.Model $filename",
+                "$exiv2 --Print xVgknldycsvt --key Iptc.Application2.Caption $filename",
+                "$exiv2 --Print xVgknldycsvt --key Xmp.dc.description $filename"]
+    stderr = [""] * len(commands)
+    stdout = ["""0x0110 set Image        Exif.Image.Model                             Model                       Model                          The model name or model number of the equipment. This is the model name or number of the DSC, scanner, video digitizer or other equipment that generated the image. When the field is left blank, it is treated as unknown. Ascii      12  12  NIKON D5300  NIKON D5300
+""",
+"""0x0078 set Application2 Iptc.Application2.Caption                    Caption                     Caption                        A textual description of the object data. String     12  12  Classic View  Classic View
+""",
+"""0x0000 set dc           Xmp.dc.description                           description                 Description                    A textual description of the content of the resource. Multiple values may be present for different languages. LangAlt     1  29  lang="x-default" Classic View  lang="x-default" Classic View
+"""
+]
+    retval = [0] * len(commands)