v.stats counts the numbers of lines, nodes, areas, islands and feature attributes in a vector file. If the count of areas or lines is noted as "incomplete," some features are unidentified in the map's dig_att file.
v.area displays the area and perimeter of vector area features selected by mouse.
v.spag corrects foreign vector data to GRASS arc-node format: it creates nodes at each line intersection, and deletes dangling lines shorter than a specified value.
v.trim copies a vector file after removing small "spurs" (dangling lines) and/or redundant nodes.
Note that these modules do not actually remove deleted vector features from the dig file. Rather, they re-code deleted areas from "A" to "a" and lines from "L" to "l" in the dig_att file.
v.clean actually removes these deleted features from the dig and dig_att files, reducing file sizes.
v.prune eliminates unnecessary vertices (according to a user-specified pruning threshold) from vector files, leaving nodes unchanged. v.digit has the same pruning capabilities.
v.cutter performs vector area overlays, cutting one map by another to create a new intersection map. Run v.spag with the -i flag on the new intersection map to remove any redundant lines.
v.mkgrid creates a vector grid map with user-specified number of rows, columns, lower-left (origin) coordinate and grid cell size.
v.mkquads creates a vector map of USGS 7.5-minute quad boundaries covering the current region. It can also output corner coordinates as a site map or text file.
v.patch combines multiple vector maps into a single output map.