Update mapproject to accept wkt, geojson, shp, prj, etc files as input to --t_srs option.

[otherorb]

It would be convenient if mapproject could read a file that has the target spatial reference data instead of requiring a string on the command line.

[otherorb]

Meant to include in this request the --t_projwin option as well.

[ShashankBice]

Hi @otherorb, maybe it is not documented, but I regularly use projection information written into a wkt file, and all ASP programs (pc_align, mapproject, point2dem) are able to parse the correct projection information from the wkt file.

[otherorb]

Thsnks @ShashankBice; I'm getting a could not parse error, so perhaps it's something on my end, though the file works in other contexts.

[oleg-alexandrov]

I think it should work to pass in a wkt in a string to --t_srs, but not as a file having the wkt. Reading the wkt from a file, given how messy it can be, is likely a worthy thing.

[dshean]

I always just do --t_srs "$(cat crs.txt)" for external text files containing WKT2, which works with PROJ/GDAL CRS parsers (which do not currently support reading WKT directly from an input text filename).

[ShashankBice]

Interesting, for some reasons ASP has been able to always correctly understand the WKT2 contents from the text file I provide, without the need of me piping the string using cat.