# latexdiff - Man Page

determine and markup differences between two latex files

## Synopsis

latexdiff [ Options ] old.tex new.tex > diff.tex

## Description

Briefly, latexdiff is a utility program to aid in the management of revisions of latex documents. It compares two valid latex files, here called old.tex and new.tex, finds significant differences between them (i.e., ignoring the number of white spaces and position of line breaks), and adds special commands to highlight the differences.  Where visual highlighting is not possible, e.g. for changes in the formatting, the differences are nevertheless marked up in the source. Note that old.tex and new.tex need to be real files (not pipes or similar) as they are opened twice (unless --encoding option is used)

The program treats the preamble differently from the main document. Differences between the preambles are found using line-based differencing (similarly to the Unix diff command, but ignoring white spaces).  A comment, "%DIF >" is appended to each added line, i.e. a  line present in new.tex but not in old.tex.  Discarded lines
are deactivated by prepending "%DIF <". Changed blocks are preceded  by comment lines giving information about line numbers in the original files.  Where there are insignificant differences, the resulting file diff.tex will be similar to new.tex.  At the end of the preamble, the definitions for latexdiff markup commands are inserted. In differencing the main body of the text, latexdiff attempts to satisfy the following guidelines (in order of priority):

1. If both old.tex and new.tex are valid LaTeX, then the resulting diff.tex should also be valid LateX. (NB If a few plain TeX commands are used within old.tex or new.tex then diff.tex is not guaranteed to work but usually will).
2. Significant differences are determined on the level of individual words. All significant differences, including differences between comments should be clearly marked in the resulting source code diff.tex.
3. If a changed passage contains text or text-producing commands, then running diff.tex through LateX should produce output where added and discarded passages are highlighted.
4. Where there are insignificant differences, e.g. in the positioning of line breaks, diff.tex should follow the formatting of new.tex

For differencing the same algorithm as diff is used but words instead of lines are compared.  An attempt is made to recognize blocks which are completely changed such that they can be marked up as a unit. Comments are differenced line by line but the number of spaces within comments is ignored. Commands including all their arguments are generally compared as one unit, i.e., no mark-up is inserted into the arguments of commands.  However, for a selected number of commands (for example, \caption and all sectioning commands) the last argument is known to be text. This text is split into words and differenced just as ordinary text (use options to show and change the list of text commands, see below). As the algorithm has no detailed knowledge of LaTeX, it assumes all pairs of curly braces immediately following a command (i.e. a sequence of letters beginning with a backslash) are arguments for that command. As a restriction to condition 1 above it is thus necessary to surround all arguments with curly braces, and to not insert extraneous spaces.  For example, write

  \section{\textem{This is an emphasized section title}}

and not

  \section {\textem{This is an emphasized section title}}

or

  \section\textem{This is an emphasized section title}

even though all varieties are the same to LaTeX (but see --allow-spaces option which allows the second variety).

For environments whose content does not conform to standard LaTeX or where graphical markup does not make sense all markup commands can be removed by setting the PICTUREENV configuration variable, set by default to picture and DIFnomarkup environments; see --config option).  The latter environment (DIFnomarkup) can be used to protect parts of the latex file where the markup results in illegal markup. You have to surround the offending passage in both the old and new file by \begin{DIFnomarkup} and \end{DIFnomarkup}. You must define the environment in the preambles of both old and new documents. I prefer to define it as a null-environment,

\newenvironment{DIFnomarkup}{}{}

but the choice is yours.  Any markup within the environment will be removed, and generally everything within the environment will just be taken from the new file.

It is also possible to difference files which do not have a preamble.
In this case, the file is processed in the main document mode, but the definitions of the markup commands are not inserted.

All markup commands inserted by latexdiff begin with "\DIF".  Added blocks containing words, commands or comments which are in new.tex but not in old.tex are marked by \DIFaddbegin and \DIFaddend. Discarded blocks are marked by \DIFdelbegin and \DIFdelend. Within added blocks all text is highlighted with \DIFadd like this: \DIFadd{Added text block} Selected safe' commands can be contained in these text blocks as well (use options to show and change the list of safe commands, see below). All other commands as well as braces “{” and “}” are never put within the scope of \DIFadd.  Added comments are marked by prepending "%DIF > ".

Within deleted blocks text is highlighted with \DIFdel.  Deleted comments are marked by prepending "%DIF < “.  Non-safe command and curly braces within deleted blocks are commented out with  ”%DIFDELCMD < ".

## Options

### Preamble

The following options determine the visual markup style by adding the appropriate command definitions to the preamble. See the end of this section for a description of  available styles.

--type=markupstyle or -t markupstyle

Add code to preamble for selected markup style. This option defines \DIFadd and \DIFdel commands. Available styles:

UNDERLINE CTRADITIONAL TRADITIONAL CFONT FONTSTRIKE INVISIBLE  CHANGEBAR CCHANGEBAR CULINECHBAR CFONTCHBAR BOLD PDFCOMMENT

[ Default: UNDERLINE ]

--subtype=markstyle or -s markstyle

Add code to preamble for selected style for bracketing commands (e.g. to mark changes in  margin). This option defines \DIFaddbegin, \DIFaddend, \DIFdelbegin and \DIFdelend commands. Available styles: SAFE MARGIN COLOR DVIPSCOL  ZLABEL ONLYCHANGEDPAGE (LABEL)*

[ Default: SAFE ] * Subtype LABEL is deprecated

--floattype=markstyle or -f markstyle

Add code to preamble for selected style which  replace standard marking and markup commands within floats (e.g., marginal remarks cause an error within floats so marginal marking can be disabled thus). This option defines all  \DIF...FL commands. Available styles: FLOATSAFE TRADITIONALSAFE IDENTICAL

[ Default: FLOATSAFE ]

--encoding=enc or -e enc

Specify encoding of old.tex and new.tex. Typical encodings are ascii, utf8, latin1, latin9.  A list of available encodings can be  obtained by executing

perl -MEncode -e 'print join ("\n",Encode-encodings( “:all” )) ;' >

If this option is used, then old.tex, new.tex are only opened once. [Default encoding is utf8 unless the first few lines of the preamble contain an invocation \usepackage[..]{inputenc} in which case the  encoding chosen by this command is asssumed. Note that ASCII (standard latex) is a subset of utf8]

--preamble=file or -p file

Insert file at end of preamble instead of generating preamble.  The preamble must define the following commands \DIFaddbegin, \DIFaddend, \DIFadd{..}, \DIFdelbegin,\DIFdelend,\DIFdel{..}, and varieties for use within floats \DIFaddbeginFL, \DIFaddendFL, \DIFaddFL{..}, \DIFdelbeginFL, \DIFdelendFL, \DIFdelFL{..} (If this option is set -t, -s, and -f options are ignored.)

--packages=pkg1,pkg2,..

Tell latexdiff that .tex file is processed with the packages in list loaded.  This is normally not necessary if the .tex file includes the preamble, as the preamble is automatically scanned for \usepackage commands. Use of the --packages option disables automatic scanning, so if for any reason package specific parsing needs to be switched off, use --packages=none. The following packages trigger special behaviour:

amsmath

Configuration variable MATHARRREPL is set to align* (Default: eqnarray*). (Note that many of the  amsmath array environments are already recognised by default as such)

endfloat

Ensure that \begin{figure} and \end{figure} always appear by themselves on a line.

hyperref

Change name of \DIFadd and \DIFdel commands to \DIFaddtex and \DIFdeltex and  define new \DIFadd and \DIFdel commands, which provide a wrapper for these commands, using them for the text but not for the link defining command (where any markup would cause errors).

apacite

Redefine the commands recognised as citation commands.

siunitx

Treat \SI as equivalent to citation commands (i.e. protect with \mbox if markup style uses ulem package.

cleveref

Treat \cref,\Cref, etc as equivalent to citation commands (i.e. protect with \mbox if markup style uses ulem package.

glossaries

Define most of the glossaries commands as safe, protecting them with \mbox'es where needed

mhchem

Treat \ce as a safe command, i.e. it will be highlighted (note that \cee will not be highlighted in equations as this leads to processing errors)

chemformula or chemmacros

Treat \ch as a safe command outside equations, i.e. it will be highlighted (note that \ch will not be highlighted in equations as this leads to processing errors)

[ Default: scan the preamble for \usepackage commands to determine

--show-preamble

Print generated or included preamble commands to stdout.

### Configuration

--exclude-safecmd=exclude-file or -A exclude-file or  --exclude-safecmd=“cmd1,cmd2,...”
--replace-safecmd=replace-file
--append-safecmd=append-file or -a append-file or --append-safecmd=“cmd1,cmd2,...”

Exclude from, replace or append to the list of regular expressions (RegEx) matching commands which are safe to use within the  scope of a \DIFadd or \DIFdel command.  The file must contain one Perl-RegEx per line (Comment lines beginning with # or % are ignored).  Note that the RegEx needs to match the whole of  the token, i.e., /^regex\$/ is implied and that the initial “\” of the command is not included.  The --exclude-safecmd and --append-safecmd options can be combined with the ---replace-safecmd  option and can be used repeatedly to add cumulatively to the lists.
--exclude-safecmd and --append-safecmd can also take a comma separated list as input. If a comma for one of the regex is required, escape it thus “\,”. In most cases it will be necessary to protect the comma-separated list from the shell by putting it in quotation marks.

--exclude-textcmd=exclude-file or -X exclude-file or --exclude-textcmd=“cmd1,cmd2,...”
--replace-textcmd=replace-file
--append-textcmd=append-file or -x append-file or --append-textcmd=“cmd1,cmd2,...”

Exclude from, replace or append to the list of regular expressions matching commands whose last argument is text.  See entry for --exclude-safecmd directly above for further details.

--replace-context1cmd=replace-file
--append-context1cmd=append-file or
--append-context1cmd=“cmd1,cmd2,...”

Replace or append to the list of regex matching commands whose last argument is text but which require a particular context to work, e.g. \caption will only work within a figure or table.  These commands behave like text commands, except when  they occur in a deleted section, when they are disabled, but their argument is shown as deleted text.

--replace-context2cmd=replace-file
--append-context2cmd=append-file or
--append-context2cmd=“cmd1,cmd2,...”

As corresponding commands for context1.  The only difference is that context2 commands are completely disabled in deleted sections, including their arguments.

context2 commands are also the only commands in the preamble, whose argument will be processed in  word-by-word mode (which only works, if they occur no more than once in the preamble). The algorithm currently cannot cope with repeated context2 commands in the preamble, as they occur e.g. for the \author argument in some journal styles (not in the standard styles, though If such a repetition is detected, the whole preamble will be processed in line-by-line mode. In such a case, use --replace-context2cmd option to just select the commands, which should be processed and are not used repeatedly in the preamble.

--exclude-mboxsafecmd=exclude-file or --exclude-mboxsafecmd=“cmd1,cmd2,...”
--append-mboxsafecmd=append-file or --append-mboxsafecmd=“cmd1,cmd2,...”

Define safe commands, which additionally need to be protected by encapsulating in an \mbox{..}. This is sometimes needed to get around incompatibilities  between external packages and the ulem package, which is  used for highlighting in the default style UNDERLINE as well as CULINECHBAR CFONTSTRIKE

--config var1=val1,var2=val2,... or -c var1=val1,..
-c configfile

Set configuration variables.  The option can be repeated to set different variables (as an alternative to the comma-separated list). Available variables (see below for further explanations):

ARRENV (RegEx)

COUNTERCMD (RegEx)

CUSTODIFCMD (RegEx)

FLOATENV (RegEx)

ITEMCMD (RegEx)

LISTENV  (RegEx)

MATHARRENV (RegEx)

MATHARRREPL (String)

MATHENV (RegEx)

MATHREPL (String)

MINWORDSBLOCK (Integer)

PICTUREENV (RegEx)

SCALEDELGRAPHICS (Float)

For configuration variables, which are a regular expression (essentially those ending in ENV, COUNTERCMD and CUSTOMDIFCMD, see list above) this option provides an alternative way to modify the configuration  variables. Instead of setting the complete pattern, with this option it is possible to add an alternative pattern. varenv must be one of the variables listed above that take a regular expression as argument, and pattern is any regular expression (which might need to be  protected from the shell by quotation). Several patterns can be added at once by using semi-colons to separate them, e.g. --add-to-config "LISTENV=myitemize;myenumerate,COUNTERCMD=endnote"

--show-safecmd

Print list of RegEx matching and excluding safe commands.

--show-textcmd

Print list of RegEx matching and excluding commands with text argument.

--show-config

Show values of configuration variables.

--show-all

Combine all --show commands.

NB For all --show commands, no old.tex or new.tex file needs to be specified, and no  differencing takes place.

### Other configuration options

--allow-spaces

Allow spaces between bracketed or braced arguments to commands.  Note that this option might have undesirable side effects (unrelated scope might get lumpeded with preceding commands) so should only be used if the default produces erroneous results.  (Default requires arguments to directly follow each other without intervening spaces).

--math-markup=level

Determine granularity of markup in displayed math environments:                Possible values for level are (both numerical and text labels are acceptable):

off or 0: suppress markup for math environments.  Deleted equations will not  appear in diff file. This mode can be used if all the other modes  cause invalid latex code.

whole or 1: Differencing on the level of whole equations. Even trivial changes to equations cause the whole equation to be marked changed.  This  mode can be used if processing in coarse or fine mode results in  invalid latex code.

coarse or 2: Detect changes within equations marked up with a coarse granularity; changes in equation type (e.g.displaymath to equation)  appear as a change to the complete equation. This mode is recommended for situations where the content and order of some equations are still being changed. [Default]

fine or 3: Detect small change in equations and mark up at fine granularity. This mode is most suitable, if only minor changes to equations are expected, e.g. correction of typos.

--graphics-markup=level
 Change highlight style for graphics embedded with C<\includegraphics> commands.

Possible values for level:

none, off or 0: no highlighting for figures

new-only or 1: surround newly added or changed figures with a blue frame [Default if graphicx package loaded]

both or 2:     highlight new figures with a blue frame and show deleted figures at reduced  scale, and crossed out with a red diagonal cross. Use configuration variable SCALEDELGRAPHICS to set size of deleted figures.

Note that changes to the optional parameters will make the figure appear as changed  to latexdiff, and this figure will thus be highlighted

--disable-citation-markup or --disable-auto-mbox

Suppress citation markup and markup of other vulnerable commands in styles  using ulem (UNDERLINE,FONTSTRIKE, CULINECHBAR) (the two options are identical and are simply aliases)

--enable-citation-markup or --enforce-auto-mbox

Protect citation commands and other vulnerable commands in changed sections  with \mbox command, i.e. use default behaviour for ulem package for other packages (the two options are identical and are simply aliases)

### Miscellaneous

--verbose or -V

Output various status information to stderr during processing. Default is to work silently.

--driver=type

Choose driver for changebar package (only relevant for styles using
changebar: CCHANGEBAR CFONTCHBAR CULINECHBAR CHANGEBAR). Possible drivers are listed in changebar manual, e.g. pdftex,dvips,dvitops
[Default: dvips]

--ignore-warnings

Suppress warnings about inconsistencies in length between input and parsed strings and missing characters.  These warning messages are often related to non-standard latex or latex constructions with a syntax unknown to latexdiff but the resulting difference argument is often fully functional anyway, particularly if the non-standard latex only occurs in parts of the text which have not changed.

--label=label or -L label

Sets the labels used to describe the old and new files.  The first use of this option sets the label describing the old file and the second use of the option sets the label for the new file, i.e. set both labels like this -L labelold -L labelnew. [Default: use the filename and modification dates for the label]

--no-label

Suppress inclusion of old and new file names as comment in output file

--visible-label

Include old and new filenames (or labels set with --label option) as  visible output.

--flatten

Replace \input and \include commands within body by the content of the files in their argument.  If \includeonly is present in the preamble, only those files are expanded into the document. However,  no recursion is done, i.e. \input and \include commands within  included sections are not expanded.  The included files are assumed to
be located in the same directories as the old and new master files, respectively, making it possible to organise files into old and new directories.  --flatten is applied recursively, so inputted files can contain further \input statements.

Use of this option might result in prohibitive processing times for larger documents, and the resulting difference document no longer reflects the structure of the input documents.

--help or -h

Show help text

--version

Show version number

### Internal options

These options are mostly for automated use by latexdiff-vc. They can be used directly, but the API should be considered less stable than for the other options.

Suppress generation of hyperreferences, used for minimal diffs (option --only-changes of latexdiff-vc)

### Major types

The major type determine the markup of plain text and some selected latex commands outside floats by defining the markup commands \DIFadd{...} and \DIFdel{...} .

UNDERLINE

Added text is wavy-underlined and blue, discarded text is struck out and red (Requires color and ulem packages).  Overstriking does not work in displayed math equations such that deleted parts of equation are underlined, not struck out (this is a shortcoming inherent to the ulem package).

Added text is blue and set in sans-serif, and a red footnote is created for each discarded  piece of text. (Requires color package)

Like CTRADITIONAL but without the use of color.

CFONT

Added text is blue and set in sans-serif, and discarded text is red and very small size.

FONTSTRIKE

Added tex is set in sans-serif, discarded text small and struck out

CCHANGEBAR

Added text is blue, and discarded text is red.  Additionally, the changed text is marked with a bar in the margin (Requires color and changebar packages).

CFONTCHBAR

Like CFONT but with additional changebars (Requires color and changebar packages).

CULINECHBAR

Like UNDERLINE but with additional changebars (Requires color, ulem and changebar packages).

CHANGEBAR

No mark up of text, but mark margins with changebars (Requires changebar package).

INVISIBLE

No visible markup (but generic markup commands will still be inserted.

BOLD

PDFCOMMENT

The pdfcomment package is used to underline new text, and mark deletions with a PDF comment. Note that this markup might appear differently or not at all based on the pdf viewer used. The viewer with best support for pdf markup is probably acroread. This style is only recommended if the number of differences is small.

### Subtypes

The subtype defines the commands that are inserted at the begin and end of added or discarded blocks, irrespectively of whether these blocks contain text or commands (Defined commands: \DIFaddbegin, \DIFaddend, \DIFdelbegin, \DIFdelend)

SAFE

MARGIN

Mark beginning and end of changed blocks with symbols in the margin nearby (using the standard \marginpar command - note that this sometimes moves somewhat from the intended position.

COLOR

An alternative way of marking added passages in blue, and deleted ones in red. (It is recommeneded to use instead the main types to effect colored markup, although in some cases coloring with dvipscol can be more complete, for example  with citation commands).

DVIPSCOL

An alternative way of marking added passages in blue, and deleted ones in red. Note that DVIPSCOL only works with the dvips converter, e.g. not pdflatex. (it is recommeneded to use instead the main types to effect colored markup, although in some cases coloring with dvipscol can be more complete).

ZLABEL

can be used to highlight only changed pages, but requires post-processing. It is recommend to not call this option manually but use latexdiff-vc with --only-changes option. Alternatively, use the script given within preamble of diff files made using this style.

ONLYCHANGEDPAGE

also highlights changed pages, without the need for post-processing, but might not work reliably if there is floating material (figures, tables).

LABEL

is similar to ZLABEL, but does not need the zref package and works less reliably (deprecated).

### Float Types

Some of the markup used in the main text might cause problems when used within  floats (e.g. figures or tables).  For this reason alternative versions of all markup commands are used within floats. The float type defines these alternative commands.

FLOATSAFE

Use identical markup for text as in the main body, but set all commands marking the begin and end of changed blocks to null-commands.  You have to choose this float type if your subtype is MARGIN as \marginpar does not work properly within floats.

Mark additions the same way as in the main text.  Deleted environments are marked by angular brackets $and$ and the deleted text is set in scriptscript size. This float type should always be used with the TRADITIONAL and  CTRADITIONAL markup types as the \footnote command does not work properly in floating environments.

IDENTICAL

Make no difference between the main text and floats.

### Configuration Variables

ARRENV

If a match to ARRENV is found within an inline math environment within a deleted or added block, then the inlined math  is surrounded by \mbox{...}.  This is necessary as underlining does not work within inlined array environments.

[ Default: ARRENV=(?:array|[pbvBV]matrix)

COUNTERCMD

If a command in a deleted block which is also in the textcmd list matches COUNTERCMD then an additional command \addtocounter{cntcmd}{-1}, where cntcmd is the matching command, is appended in the diff file such that the numbering in the diff file remains synchronized with the numbering in the new file.

[ Default: COUNTERCMD=(?:footnote|part|section|subsection ...

|subsubsection|paragraph|subparagraph)  ]

CUSTOMDIFCMD

This option is for advanced users and allows definition of special versions of commands, which do not work as safe commands.

Commands in CUSTOMDIFCMD that occur in added or deleted blocks will be given an ADD or DEL prefix. The prefixed versions of the command must be defined in the preamble, either by putting them  in the preamble of at least the new file, or by creating a custom preamble file (Option --preamble). For example the command \blindtext (from package blindtext) does not interact well with underlining, so that  for the standard markup type, it is not satisfactory to define it as a safe command. Instead, a customised versions without underlining can be defined in the preamble:

\newcommand{\DELblindtext}{{\color{red}\blindtext}}

\newcommand{\ADDblindtext}{{\color{blue}\blindtext}}

and then latexdiff should be invoked with the option -c CUSTOMDIFCMD=blindtext.

[ Default: none ]

FLOATENV

Environments whose name matches the regular expression in FLOATENV are  considered floats.  Within these environments, the latexdiff markup commands are replaced by their FL variaties.

[ Default: (?:figure|table|plate)[\w\d*@]* ]

ITEMCMD

Commands representing new item line with list environments.

[ Default: \item ]

LISTENV

Environments whose name matches the regular expression in LISTENV are list environments.

[ Default: (?:itemize|enumerate|description) ]

MATHENV,MATHREPL

If both \begin and \end for a math environment (environment name matching MATHENV or $and$) are within the same deleted block, they are replaced by a \begin and \end commands for MATHREPL rather than being commented out.

[ Default: MATHENV=(?:displaymath|equation) , MATHREPL=displaymath ]

MATHARRENV,MATHARRREPL

as MATHENV,MATHREPL but for equation arrays

[ Default: MATHARRENV=eqnarray\*? , MATHREPL=eqnarray ]

MINWORDSBLOCK

Minimum number of tokens required to form an independent block. This value is used in the algorithm to detect changes of complete blocks by merging identical text parts of less than MINWORDSBLOCK to the preceding added and discarded parts.

[ Default: 3 ]

PICTUREENV

Within environments whose name matches the regular expression in PICTUREENV all latexdiff markup is removed (in pathologic cases this might lead to inconsistent markup but this situation should be rare).

[ Default: (?:picture|DIFnomarkup)[\w\d*@]* ]

SCALEDELGRAPHICS

If --graphics-markup=both is chosen, SCALEDELGRAPHICS is the factor, by which deleted figures will be scaled (i.e. 0.5 implies they are shown at half linear size).

[ Default: 0.5 ]

VERBATIMENV

RegEx describing environments like verbatim, whose contents should be taken verbatim. The content of these environments will not be processed in any way:  deleted content is commented out, new content is not marked up

[ Default:  comment  ]

VERBATIMLINEENV

RegEx describing environments like verbatim, whose contents should be taken verbatim. The content of environments described by VERBATIMLINEENV are compared in  line mode, and changes are marked up using the listings package. The markup style is set based on the chosen mains markup type (Option -t), or on an analysis of the preamble. Note that “listings.sty” must be installed. If this file is not found the fallback solution is to  treat VERBATIMLINEENV environments treated exactly the same way as VERBATIMENV environments.

[ Default:  (?:verbatim[*]?|lstlisting  ]

## Common Problems and FAQ

Citations result in overfull boxes

There is an incompatibility between the ulem package, which latexdiff uses for underlining and striking out in the UNDERLINE style, the default style, and the way citations are generated. In order to be able to mark up citations properly, they are enclosed with an \mbox  command. As mboxes cannot be broken across lines, this procedure frequently results in overfull boxes, possibly obscuring the content as it extends beyond the right margin.  The same occurs for some other packages (e.g., siunitx). If this is a problem, you have two possibilities.

1. Use CFONT type markup (option -t CFONT): If this markup is chosen, then changed citations are no longer marked up with the wavy line (additions) or struck out (deletions), but are still highlighted in the appropriate color, and deleted text is shown with a different font. Other styles not using the ulem package will also work.

2. Choose option --disable-citation-markup which turns off the marking up of citations: deleted citations are no longer shown, and added citations are shown without markup. (This was the default behaviour of latexdiff at versions 0.6 and older)

For custom packages you can define the commands which need to be protected by \mbox with --append-mboxsafecmd and --excludemboxsafecmd options (submit your lists of command as feature request at github page to set the default behaviour of future versions, see section 6)

Changes in complicated mathematical equations result in latex processing errors

Try options --math-markup=whole.   If even that fails, you can turn off mark up for equations with --math-markup=off.

How can I just show the pages where changes had been made

Use options --s ZLABEL  (some postprocessing required) or -s ONLYCHANGEDPAGE. latexdiff-vc --ps|--pdf with --only-changes option takes care of the post-processing for you (requires zref package to be installed).

## Bugs

Option allow-spaces not implemented entirely consistently. It breaks the rules that number and type of white space does not matter, as different numbers of inter-argument spaces are treated as significant.

Please submit bug reports using the issue tracker of the github repository page https://github.com/ftilmann/latexdiff.git,  or send them to tilmann — AT — gfz-potsdam.de.  Include the version number of latexdiff (from comments at the top of the source or use --version).  If you come across latex files that are error-free and conform to the specifications set out above, and whose differencing still does not result in error-free latex, please send me those files, ideally edited to only contain the offending passage as long as that still reproduces the problem. If your  file relies on non-standard class files, you must include those.  I will not look at examples where I have trouble to latex the original files.

latexrevise, latexdiff-vc

## Portability

latexdiff does not make use of external commands and thus should run on any platform  supporting Perl 5.6 or higher.  If files with encodings  other than ASCII or UTF-8 are processed, Perl 5.8 or higher is required.

The standard version of latexdiff requires installation of the Perl package Algorithm::Diff` (available from www.cpan.org -  http://search.cpan.org/~nedkonz/Algorithm-Diff-1.15) but a stand-alone version, latexdiff-so, which has this package inlined, is available, too. latexdiff-fast requires the diff command to be present.

## Author

Version 1.3.0 Copyright (C) 2004-2018 Frederik Tilmann

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License Version 3

Contributors of fixes and additions: V. Kuhlmann, J. Paisley, N. Becker, T. Doerges, K. Huebner,  T. Connors, Sebastian Gouezel and many others. Thanks to the many people who sent in bug reports, feature suggestions, and other feedback.

## Info

2018-10-07 perl v5.22.1