My bash script has the following code generate invocation for "Protocol Buffers".
protoc --proto_path=src --java_out=src
That was from 2012. Today the online documentation for Java Protocol Buffers says:
protoc -I=$SRC_DIR --java_out=$DST_DIR
This makes it seem like
--proto_path is superceded. What was the purpose of
--proto_path are the same flag:
-I is the shorthand version.
The purpose of the flag is to specify a directory in which to look for imported files, much like the C compiler's
-I flag, Java's
CLASSPATH environment variable, Python's
PYTHONPATH, etc. You may specify multiple directories by passing multiple
-I flags; they will be searched in order.