geo.go

Documentation: github.com/gabriel-vasile/mimetype/internal/magic

     1  package magic
     2  
     3  import (
     4  	"bytes"
     5  	"encoding/binary"
     6  )
     7  
     8  // Shp matches a shape format file.
     9  // https://www.esri.com/library/whitepapers/pdfs/shapefile.pdf
    10  func Shp(raw []byte, limit uint32) bool {
    11  	if len(raw) < 112 {
    12  		return false
    13  	}
    14  
    15  	if !(binary.BigEndian.Uint32(raw[0:4]) == 9994 &&
    16  		binary.BigEndian.Uint32(raw[4:8]) == 0 &&
    17  		binary.BigEndian.Uint32(raw[8:12]) == 0 &&
    18  		binary.BigEndian.Uint32(raw[12:16]) == 0 &&
    19  		binary.BigEndian.Uint32(raw[16:20]) == 0 &&
    20  		binary.BigEndian.Uint32(raw[20:24]) == 0 &&
    21  		binary.LittleEndian.Uint32(raw[28:32]) == 1000) {
    22  		return false
    23  	}
    24  
    25  	shapeTypes := []int{
    26  		0,  // Null shape
    27  		1,  // Point
    28  		3,  // Polyline
    29  		5,  // Polygon
    30  		8,  // MultiPoint
    31  		11, // PointZ
    32  		13, // PolylineZ
    33  		15, // PolygonZ
    34  		18, // MultiPointZ
    35  		21, // PointM
    36  		23, // PolylineM
    37  		25, // PolygonM
    38  		28, // MultiPointM
    39  		31, // MultiPatch
    40  	}
    41  
    42  	for _, st := range shapeTypes {
    43  		if st == int(binary.LittleEndian.Uint32(raw[108:112])) {
    44  			return true
    45  		}
    46  	}
    47  
    48  	return false
    49  }
    50  
    51  // Shx matches a shape index format file.
    52  // https://www.esri.com/library/whitepapers/pdfs/shapefile.pdf
    53  func Shx(raw []byte, limit uint32) bool {
    54  	return bytes.HasPrefix(raw, []byte{0x00, 0x00, 0x27, 0x0A})
    55  }
    56
View as plain text