gdalbuildvrt
Build Virtual Datasets from a list of existing datasets.
TLDR
Make a virtual mosaic from all TIFF files contained in a directory
$ gdalbuildvrt [path/to/output.vrt] [path/to/input_directory/*.tif]
Make a virtual mosaic from files whose name is specified in a text file
$ gdalbuildvrt -input_file_list [path/to/list.txt] [path/to/output.vrt]
Make an RGB virtual mosaic from 3 single-band input files
$ gdalbuildvrt -separate [path/to/rgb.vrt] [path/to/red.tif] [path/to/green.tif] [path/to/blue.tif]
Make a virtual mosaic with blue background color (RGB: 0 0 255)
$ gdalbuildvrt -hidenodata -vrtnodata "[0 0 255]" [path/to/output.vrt] [path/to/input_directory/*.tif]
