Filechan input is interpreted as a set of lines.
Each line contains a fixed number of initial fields, followed by a variable number of filename fields. All fields in a line are separated by whitespace. The default number of initial fields is one. For each line of input, filechan writes the initial fields, separated by whitespace and followed by a newline, to each of the files named in the filename fields. When writing to a file, filechan opens it in append mode and tries to lock it and change the ownership to the user and group who owns the directory where the file is being written.