DOC: Better help text for loadFiles

src/caosadvancedtools/loadFiles.py

@@ -190,7 +190,26 @@ def main(argv=None):
         sys.argv.extend(argv)
 
     # Setup argument parser
-    parser = ArgumentParser()
+    parser = ArgumentParser(description="""
+Make files that the LinkAhead server can see available als FILE entities.
+
+In a typical scenario where LinkAhead runs in a Docker container and a host directory `mydir` is
+mounted as an extroot with name `myext`, loadfiles could be called like this:
+
+> loadFiles -p foo /opt/caosdb/mnt/extroot/myext/
+
+This call would result in
+
+1. On the LinkAhead server: There are FILE entities for all files in `mydir`.
+2. In the `caosroot` directory inside the Docker image, there are symlinks like this:
+
+    foo/myext/somefile.txt -> /opt/caosdb/mnt/extroot/myext/somefile.txt
+    foo/myext/dir/other.bin -> /opt/caosdb/mnt/extroot/myext/dir/other.bin
+
+The FILE entity for `somefile.txt` for example now has the path "foo/myext/somefile.txt" and its
+content can be retrieved via LinkAhead's API.
+
+""", formatter_class=argparse.RawDescriptionHelpFormatter)
     parser.add_argument("-p", "--prefix", dest="prefix",
                         help="store files with this prefix into the server's"
                         " file system.")