go-shp

Go library for reading and writing ESRI Shapefiles. This is a pure Golang implementation based on the ESRI Shapefile technical description.

Usage

Installation

go get github.com/jonas-p/go-shp

Importing

import "github.com/jonas-p/go-shp"

Examples

Reading a shapefile

// open a shapefile for reading
shape, err := shp.Open("points.shp")
if err != nil { log.Fatal(err) } 
defer shape.Close()

// fields from the attribute table (DBF)
fields := shape.Fields()

// loop through all features in the shapefile
for shape.Next() {
    n, p := shape.Shape()

    // print feature
    fmt.Println(reflect.TypeOf(p).Elem(), p.BBox())

    // print attributes
    for k, f := range fields {
        val := shape.ReadAttribute(n, k)
        fmt.Printf("\t%v: %v\n", f, val)
    }
    fmt.Println()
}

Creating a shapefile

// points to write
points := []shp.Point{
    shp.Point{10.0, 10.0},
    shp.Point{10.0, 15.0},
    shp.Point{15.0, 15.0},
    shp.Point{15.0, 10.0},
}

// fields to write
fields := []shp.Field{
    // String attribute field with length 25
    shp.StringField("NAME", 25),
}

// create and open a shapefile for writing points
shape, err := shp.Create("points.shp", shp.POINT)
if err != nil { log.Fatal(err) }
defer shape.Close()

// setup fields for attributes
shape.SetFields(fields)

// write points and attributes
for n, point := range points {
    shape.Write(&point)

    // write attribute for object n for field 0 (NAME)
    shape.WriteAttribute(n, 0, "Point " + strconv.Itoa(n + 1))
}

Resources

• Documentation on godoc.org
• ESRI Shapefile Technical Description