The command format is:
# installp -d <directory-name> -a all ## to install everything in directory
Note: when directory-name is a file-name, it only looks at that one file.
To see what is in a directory (read, what installp sees as being offered) compare
# installd -d <file-name> -L
with
# inutoc <dir-name> # just to be sure the .toc aka table-of-contents data is current
# installp -d <dir-name> -L
Hope this helps!