Provided by: shapelib_1.3.0-5_amd64 
NAME
shprewind - validates and resets the winding order of rings
SYNOPSIS
shprewind in_shp_file out_shp_file
DESCRIPTION
Validates and resets the winding order of rings in polygon geometries to match the ordering required by
shapefile specification. This is useful for shapefiles having troubles when checked with a ´shpdump
-validate´.
Makes a copy of the shapefile in_shp_file to out_shp_file and fixes the orientation of points in the
rings of Polygon, PolygonZ, and PolygonM typed shapes to conform to the shapefile specification.
According to the specification, the vertices of outer rings should be oriented clockwise on the X/Y
plane, and those of inner rings counterclockwise.
Shapefiles actually consist of two files with the same basename and extensions .shp and .shx (or .SHP and
.SHX) containing the shape data and shape index respectively. The files to open are determined by first
stripping any filename extension from in_shp_file and attempting to open the files in_shp_file.shp or
in_shp_file.SHP, and in_shp_file.shx or in_shp_file.SHX for the respective data and index files. The
files to create from out_shp_file are determined by stripping any filename extension from out_shp_file
and appending .shp and .shx suffixes for the respective data and index files.
OPTIONS
in_shp_file
the name of an existing shapefile.
out_shp_file
the name of the new fixed shapefile that will be created.
EXIT STATUS
0 Successful program execution.
1 Missing in_shp_file or out_shp_file arguments, failed to open shapefile in_shp_file or create
shapefile out_shp_file.
DIAGNOSTICS
The following diagnostics may be issued on stdout:
Unable to open:in_shp_file
Unable to create:out_shp_file
count objects rewound.
EXAMPLE
shprewind badshapefile newshapefile
AUTHOR
shprewind is part of shapelib, maintained by Frank Warmerdam. This guide was created by Eduardo Patoo
Kanegae and converted to manpage by Johan Van de Wauw. It was further enhanced with the man page written
by Joonas Pihlaja (jpihlaja@cc.helsinki.fi).
BUGS
The implementation assumes that there is at most one outer ring in each shape, that it is the first ring
in a shape, and all other rings in a shape are inner rings. Polygons inside MultiPatch shape types aren´t
rewound.
SEE ALSO
dbfadd(1), dbfcat(1), dbfcreate(1), dbfdump(1), dbfinfo(1), shpadd(1), shpcat(1), shpcentrd(1), shpcreate(1), shpdump(1), shpdxf(1), shpfix(1), shpinfo(1), shpproj(1), shptest(1) August 2015 SHPREWIND(1)