execute a command as another user

list directory contents

-1     (The numeric digit one.) Force output to be one entry per line.

-d     Do not follow symbolic links named as operands unless the -H or -L options are specified.  Do  not
       treat  directories  differently  than  other  types  of  files.  The  use  of  -d with -R produces
       unspecified results.

-s     Indicate the total number of file system blocks consumed by each file displayed. The block size is
       implementation-defined.