Ubuntu Manpage: osmium-derive-changes - create OSM change files from two OSM data files

NAME

       osmium-derive-changes - create OSM change files from two OSM data files

SYNOPSIS

       osmium derive-changes [OPTIONS] OSM-FILE1 OSM-FILE2

DESCRIPTION

Finds differences between two OSM files and creates a change file with those differences.
The resulting change file is created in a way, that it could be applied on OSM-FILE1 to
re-create OSM-FILE2.

Objects in both input files must be sorted by type, ID, and version. The first input file
must be from a point in time before the second input file.

Only object type, id, and version are compared, so this program will not detect
differences in, say, the tags, unless the object has a new version, which is the normal
way things work in OSM. If you need to compare all data in OSM files, have a look at the
osmium diff program.

For this command to create a proper change file you have to set the --output option or
--output-format option in a way that it will generate an .osc file, typically by using
something like '-o out.osc.gz'. You can create any other OSM file format, but that is
usually not what you want. Osmium derive-changes will warn you in this case.

Note that for objects that are in OSM-FILE1 but not OSM-FILE2 a "deleted" entry will be
created in the output. But because we can not know when this deletion actually occurred,
in which changeset, and by which user, it is unclear what attributes this deleted object
should have. Also, if you are working with extracts, the object might not actually have
been deleted in the OSM database, but just moved out of the extract you are looking at.
So a real, new, "deleted" version was never created. Usually the "deleted" object will
get the same version number and timestamp as the object in OSM-FILE1 had, all other
information will be removed. But you can change this using the --increment-version,
--keep-details, and --update-timestamp options. Depending on which software you are using
the change files with, different settings might be necessary.

This commands reads its input files only once and writes its output file in one go so it
can be streamed, ie. it can read from STDIN and write to STDOUT.

OPTIONS

       --increment-version
              Increment version number of deleted objects.

       --keep-details
              Keep details of deleted objects.  Usually only id, version, and timestamp are kept.
              If  this  option is set all attributes, all tags, and all nodes or members for ways
              and relations, respectively, are kept.

       --update-timestamp
              Update timestamp of deleted  objects  to  the  current  time.   This  is  the  same
              behaviour as Osmosis.

COMMON OPTIONS

       -h, --help
              Show usage help.

       -v, --verbose
              Set  verbose  mode.   The program will output information about what it is doing to
              STDERR.

INPUT OPTIONS

       -F, --input-format=FORMAT
              The format of the input file(s).  Can be used to set the input format if  it  can't
              be  autodetected  from  the  file  name(s).  This will set the format for all input
              files, there is no  way  to  set  the  format  for  some  input  files  only.   See
              osmium-file-formats(5) or the libosmium manual for details.

OUTPUT OPTIONS

       -f, --output-format=FORMAT
              The  format  of  the  output file.  Can be used to set the output file format if it
              can't be autodetected from the output file name.  See osmium-file-formats(5) or the
              libosmium manual for details.

       --fsync
              Call fsync after writing the output file to force flushing buffers to disk.

       --generator=NAME
              The  name  and version of the program generating the output file.  It will be added
              to the header of the output file.  Default is "osmium/" and the version of osmium.

       -o, --output=FILE
              Name of the output file.  Default is '-' (STDOUT).

       -O, --overwrite
              Allow an existing output file to be overwritten.  Normally osmium  will  refuse  to
              write over an existing file.

       --output-header=OPTION
              Add  output  header  option.   This  option  can  be  given several times.  See the
              libosmium manual for a list of allowed header options.

DIAGNOSTICS

       osmium derive-changes exits with exit code

       0      if everything went alright,

       1      if there was an error processing the data, or

       2      if there was a problem with the command line arguments.

MEMORY USAGE

       osmium derive-changes doesn't keep a lot of data in memory.

EXAMPLES

       Find changes in Nepal extract in January 2016:

              osmium derive-changes nepal-20160101.osm.pbf nepal-20160201.osm.pbf -o nepal-jan.osc.bz2

COPYRIGHT

       Copyright (C) 2013-2017 Jochen Topf <jochen@topf.org>.

       License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.   This  is
       free  software:  you are free to change and redistribute it.  There is NO WARRANTY, to the
       extent permitted by law.

CONTACT

       If   you   have   any   questions   or   want   to   report   a   bug,   please   go    to
       http://osmcode.org/contact.html

AUTHORS

       Jochen Topf <jochen@topf.org>.

                                              1.7.1                      OSMIUM-DERIVE-CHANGES(1)