OGR Shapefile – How to Access Shapefile Metadata

gdalogrshapefile

I'm trying to use ogrinfo to get some details on a shapefile I downloaded. Currently, the only way I know how to do this is to load it into QGIS and manually click around to find any information on it, like opening the attribute table.

I just want to be able to see any metadata is tagged along with the features. If I do:

ogrinfo -al USA_adm0.shp

I can see at the beginning there is a lot of useful information, but then it flies past with all the feature data.

Can someone help me out?

EDIT

This is what I get on my mac using the -ro and -so flag, doesn't seem to be much help.

->ogrinfo -ro -so USA_adm0.shp
INFO: Open of `USA_adm0.shp'
      using driver `ESRI Shapefile' successful.
1: USA_adm0 (Polygon)

Best Answer

ogrinfo can shorten the output considerably using the -so flag.

-so: Summary Only: supress listing of features, show only the summary information like projection, schema, feature count and extents.

So ogrinfo -ro -so file.shp should give a summary of the metadata.

And

-al: List all features of all layers (used instead of having to give layer names as arguments).

Would certainly give you a lot of info on the other hand if used by itself!

And if you want to see metadata for individual or a range of features, there is the -fid, -where, and -sql flags which do that.

Lastly, -geom will act as a master toggle for the geometry info.

-geom={YES/NO/SUMMARY}: (starting with GDAL 1.6.0) If set to NO, the feature dump will not display the geometry. If set to SUMMARY, only a summary of the geometry will be displayed. If set to YES, the geometry will be reported in full OGC WKT format. Default value is YES.

There is a FAQVector Wiki with examples for GDAL command line utilities that also gives some other tips =)

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[GIS] Extracting land cover data (in percent) from shapefile in QGIS

There many forms to do it. If you convert your data to raster you may use Lecos plugin.

See the tutorial below https://conservationecology.wordpress.com/2013/04/01/another-lecos-update-and-more-to-follow-in-the-near-future/

If you would like to maintain your data in vector follow this steps: 1) Compute the area of catchment stream 2) Run intersect catchment stream with you landscape classification 3) Dissolve all polygons of "intersetion result" 4) Divide area (field) of "intersection result" (that was made in number 3) with the catchment stream (that was made in number 1) and multiple to 100.

Then you will have result that you would like.

Good luck.

OGR – How to Access Shapefile Metadata and Metatypes Information

A very quick way would be to use the linux command line utility tail as follows:

ogrinfo -ro -so -al  BRA_001.shp | tail -n + 20

However, this won't always be reprocible if the SRS is different. As user30184 mentioned, you would need to use the OGR API. The following example is in Python:

from osgeo import ogr
shpFile = r"./BRA_001.shp"

dataSource = ogr.Open(shpFile)
layer = dataSource.GetLayer(0)
layerDefn = layer.GetLayerDefn()

for i in range(layerDefn.GetFieldCount()):
    fieldName = layerDefn.GetFieldDefn(i).GetName()
    fieldTypeCode = layerDefn.GetFieldDefn(i).GetType()
    fieldType = layerDefn.GetFieldDefn(i).GetFieldTypeName(fieldTypeCode)
    fieldWidth =  layerDefn.GetFieldDefn(i).GetPrecision()

    print str(fieldName) + ": " + str(fieldType) + " (" + str(fieldWidth) + ")"

Here is an example that prints the output as a JSON Array:

import sys
try:
    from osgeo import ogr, gdal
except:
    sys.exit('[ ERROR ]: cannot find GDAL/OGR modules')



def printMetadata(daShapefile):
    dataSource = ogr.Open(daShapefile)
    daLayer  = dataSource.GetLayer(0)
    layerDefinition = daLayer.GetLayerDefn()

    c = layerDefinition.GetFieldCount()
        print "["
    for i in range(c):
        fieldName =  layerDefinition.GetFieldDefn(i).GetName()
        fieldTypeCode = layerDefinition.GetFieldDefn(i).GetType()
        fieldType = layerDefinition.GetFieldDefn(i).GetFieldTypeName(fieldTypeCode)
        fieldWidth = layerDefinition.GetFieldDefn(i).GetWidth()
        GetPrecision = layerDefinition.GetFieldDefn(i).GetPrecision()

        if((c - 1) != i):
            scape  = ','
        else:
            scape  = ""

        print("{\"name\":\"%s\",\"type\":\"%s\",\"length\":%s,\"precision\":%s}%s" % (fieldName,fieldType,str(fieldWidth),str(GetPrecision),scape))

    print "]"

if len( sys.argv ) < 2:
    sys.exit('[ ERROR ]: You must define a file ')
else:
    file_path_name = sys.argv[1]
    printMetadata(sys.argv[1])

EDIT

Best Answer

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OGR – How to Access Shapefile Metadata and Metatypes Information

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