[gdal-dev] ERROR 4: `test.asc' not recognised as a supported file format.

[Hermann Peifer]

Hi,

Occasionally I use a small .asc file, which I then gdal_translate into a 
bigger blank GeoTIFF. I tried to make the smallest possible test.asc 
file with 1 col x 1 row and 1 cell value only, but I ended up with ERROR 
4: file not recognised as a supported file format.

The error message seems to go away after adding (useless) values to the 
file, see below.

I am wondering if this is a feature or rather a bug?

Thanks for your time, Hermann

----------

$ gdalinfo --debug on test.asc
ERROR 4: `test.asc' not recognised as a supported file format.

gdalinfo failed - unable to open 'test.asc'.


$ gdalinfo --debug on test2.asc
GDAL: GDALOpen(test2.asc, this=0xab0610) succeeds as AAIGrid.
Driver: AAIGrid/Arc/Info ASCII Grid
Files: test2.asc
Size is 1, 1
Coordinate System is `'
Origin = (0.000000000000000,1.000000000000000)
Pixel Size = (1.000000000000000,-1.000000000000000)
Corner Coordinates:
Upper Left  (   0.0000000,   1.0000000)
Lower Left  (   0.0000000,   0.0000000)
Upper Right (   1.0000000,   1.0000000)
Lower Right (   1.0000000,   0.0000000)
Center      (   0.5000000,   0.5000000)
Band 1 Block=1x1 Type=Int32, ColorInterp=Undefined
GDAL: GDALClose(test2.asc, this=0xab0610)


$ gdalinfo --debug on test3.asc
GDAL: GDALOpen(test3.asc, this=0x16c5610) succeeds as AAIGrid.
Driver: AAIGrid/Arc/Info ASCII Grid
Files: test3.asc
Size is 1, 1
Coordinate System is `'
Origin = (0.000000000000000,1.000000000000000)
Pixel Size = (1.000000000000000,-1.000000000000000)
Corner Coordinates:
Upper Left  (   0.0000000,   1.0000000)
Lower Left  (   0.0000000,   0.0000000)
Upper Right (   1.0000000,   1.0000000)
Lower Right (   1.0000000,   0.0000000)
Center      (   0.5000000,   0.5000000)
Band 1 Block=1x1 Type=Int32, ColorInterp=Undefined
GDAL: GDALClose(test3.asc, this=0x16c5610)


$ cat test.asc
ncols         1
nrows         1
xllcorner     0
yllcorner     0
cellsize      1
0
$ cat test2.asc
ncols         1
nrows         1
xllcorner     0
yllcorner     0
cellsize      1
0 0 0 0 0 0 0 0 0 0
$ cat test3.asc
ncols         1
nrows         1
xllcorner     0
yllcorner     0
cellsize      1
123456789 987654321
$