MAPFILE

Mapfile is a term used in computing to refer to files that contain map-related configuration or data, or to a Bash shell builtin with similar naming. In Unix-like environments, the most common reference is to a Bash builtin called mapfile (also known as readarray), introduced in Bash 4.0. This command reads lines from standard input or from a file descriptor into an indexed array. If a target array name is supplied, the lines are stored there; otherwise the default array MAPFILE is used. Options include -t to strip trailing newlines, -n to limit how many lines are read, -d to specify a line delimiter, and -A to select the target array. It is frequently used to capture command output or file contents into a shell array for further processing.

In GIS software, a mapfile refers to a configuration file used by MapServer, a web mapping engine. The mapfile defines the map instance and its layers via a MAP block and nested LAYER blocks. A mapfile specifies settings such as the map size, projection, and extent, as well as data sources, layer types, and styling. MapServer reads the mapfile to render maps, produce image outputs, or deliver metadata. The syntax is plain text and emphasizes hierarchical blocks, typically including sections for the map, its layers, and styling classes.

Beyond these contexts, the term mapfile can appear in other software ecosystems to denote a file that maps data sources to visual or processing outputs. Because the exact meaning depends on the software, users should consult the specific application's documentation for precise syntax and semantics. In summary, mapfile commonly denotes either a Bash mechanism for loading file lines into arrays or a configuration file that guides map rendering in MapServer, with variations across tools.