DTDDIFF(1p)

💖 DTDDIFF 💖

okay bestie, gather round, because this is dtddiff from the 1p manual — the perl-contributed-pages girlies know — and she is here to compare two SGML/XML DTDs and tell you exactly what changed. no cap. 🦋

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✨ NAME ✨

dtddiff — compare two SGML/XML DTDs. that's it. that's the whole job. she's focused, she's iconic, she's not doing anything else. 💅

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🌸 SYNOPSIS 🌸

dtddiff [options] <parsed-dtd1.xml> <parsed-dtd2.xml>

two parsed XML files, in, in that order. options go first. that's the vibe. ✨

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🎀 DESCRIPTION 🎀

so here's the tea: dtddiff compares two SGML/XML DTDs, and it does it based on the XML dumps that dtdparse generates. like, you don't hand it raw DTDs — you hand it the parsed versions. here's the typical usage flow, literally:

dtdparse --outfile parsed-dtd1.xml dtd1.dtd
dtdparse --outfile parsed-dtd2.xml dtd2.dtd
dtddiff parsed-dtd1.xml parsed-dtd2.xml > dtd.diff

and the reason it works this way? because dtddiff is chewing on the XML dumps from dtdparse, it gets to avoid a full reparse of the DTDs. obsessed. efficiency queen. 🔥

dtddiff does a structural-based comparison. which means — and this is the important part, bestie — the order of declarations in the DTDs does not affect the comparison. move stuff around all you want, she sees through it. ✨

the output is similar in style to a context-based diff, like the one diff(1) does. here's an example of the kind of output she generates:

*** DocBook 4.1 DTD
--- DocBook 4.2 DTD
*************** Elements Added
--- DocBook 4.2 DTD ----
+ bibliocoverage
+ biblioid
+ bibliorelation
+ bibliosource
+ blockinfo
+ citebiblioid
+ coref
+ errortext
+ personblurb
+ personname
+ refsection
+ refsectioninfo
+ textdata
*************** Elements Changed
... [snip] ...

*** DocBook 4.1 DTD ****

! entrytbl ::=
      (colspec*, spanspec*, thead?, tbody)
     -(entrytbl)

   entrytbl Attributes:
!   charoff                NUTOKEN                    #IMPLIED
!   colname                NMTOKEN                    #IMPLIED
!   cols                   NUMBER                     #REQUIRED
!   colsep                 NUMBER                     #IMPLIED
!   nameend                NMTOKEN                    #IMPLIED
!   namest                 NMTOKEN                    #IMPLIED
!   rowsep                 NUMBER                     #IMPLIED
!   spanname               NMTOKEN                    #IMPLIED
!   tgroupstyle            NMTOKEN                    #IMPLIED

--- DocBook 4.2 DTD ----

! entrytbl ::=
      (colspec*, spanspec*, thead?, tbody)

   entrytbl Attributes:
!   charoff                CDATA                      #IMPLIED
!   colname                CDATA                      #IMPLIED
!   cols                   CDATA                      #REQUIRED
!   colsep                 CDATA                      #IMPLIED
!   nameend                CDATA                      #IMPLIED
!   namest                 CDATA                      #IMPLIED
!   rowsep                 CDATA                      #IMPLIED
!   spanname               CDATA                      #IMPLIED
!   tgroupstyle            CDATA                      #IMPLIED

... [snip] ...

*** DocBook 4.1 DTD ****

   graphic Attributes:
!   depth                  NUTOKEN                    #IMPLIED
!   format                 [Enumeration]              #IMPLIED
!                          BMP, CGM-CHAR, CGM-
!                          BINARY, CGM-CLEAR,
!                          DITROFF, DVI, EPS, EQN,
!                          FAX, GIF, GIF87a, GIF89a,
!                          JPG, JPEG, IGES, PCX,
!                          PIC, PNG, PS, SGML, TBL,
!                          TEX, TIFF, WMF, WPG,
!                          linespecific
!   scale                  NUMBER                     #IMPLIED
!   scalefit               NUMBER                     #IMPLIED
!   width                  NUTOKEN                    #IMPLIED

--- DocBook 4.2 DTD ----

   graphic Attributes:
+   contentdepth           CDATA                      #IMPLIED
+   contentwidth           CDATA                      #IMPLIED
+   valign                 [Enumeration]              #IMPLIED
+                          top, middle, bottom
!   depth                  CDATA                      #IMPLIED
!   format                 [Enumeration]              #IMPLIED
!                          BMP, CGM-CHAR, CGM-
!                          BINARY, CGM-CLEAR,
!                          DITROFF, DVI, EPS, EQN,
!                          FAX, GIF, GIF87a, GIF89a,
!                          JPG, JPEG, IGES, PCX,
!                          PIC, PNG, PS, SGML, TBL,
!                          TEX, TIFF, WMF, WPG, SVG,
!                          linespecific
!   scale                  CDATA                      #IMPLIED
!   scalefit               CDATA                      #IMPLIED
!   width                  CDATA                      #IMPLIED

... [snip] ...

now, the decoder ring for those lil symbols at the start of lines, because iykyk:

• lines starting with "- " — that's a minus followed by a space, bestie — denote items removed. 💀
• lines starting with "+ " — a plus followed by a space — denote items added. ✨
• lines starting with "! " — an exclamation point followed by a space — denote items changed. 😭

periodt.

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💅 OPTIONS 💅

• --attributes, --noattributes — print, or not, element attribute differences. the default is to print differences. ✨
• --content-model-expanded, --nocontent-model-expanded — expand, or not expand, element content models during comparison. expanded models have all parameter entities resolved. the default is to use expanded content model.
• --elements, --noelements — print, or not, element content model differences. the default is to print differences.
• --general-ents, --nogeneral-ents — print, or not, general entity differences. the default is to not print differences.
• --parameter-ents, --noparameter-ents — print, or not, parameter entity differences. the default is to not print differences.
• --dump — do a textual dump of a DTD. when this option is specified, only a single DTD is dumped. this is mainly used for debugging purposes. 🐛
• --version — print version and synopsis.
• --help — print synopsis and options available.
• --man — print manual page.

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🦋 SEE ALSO 🦋

• dtdparse
• dtddiff2html

see SGML::DTDParse for an overview of the DTDParse package. that's where all the lore lives, bestie. 📚

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🧚 PREREQUISITES 🧚

she needs her girls:

• File::Basename
• Getopt::Long
• Xml::Parser

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🌈 AVAILABILITY 🌈

http://dtdparse.sourceforge.net/

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👑 AUTHORS 👑

Earl Hood, <earl@earlhood.com> 💌

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🌸 COPYRIGHT AND LICENSE 🌸

see SGML::DTDParse for copyright and license information. (she's keeping it mysterious. we respect it.) ✨

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okay that's the whole page, we're done here. this one shipped as perl v5.32.1, dated 2022-01-21, and honestly? she ate. 🫶💖 bye bestie, go diff some DTDs. 🎀