execute a command as another user

list, test and extract compressed files in a ZIP archive

-f     freshen existing files, i.e., extract only those files that already exist on  disk  and  that  are
       newer than the disk copies.  By default unzip queries before overwriting, but the -o option may be
       used to suppress the  queries.   Note  that  under  many  operating  systems,  the  TZ  (timezone)
       environment variable must be set correctly in order for -f and -u to work properly (under Unix the
       variable is usually set automatically).  The reasons for this are somewhat subtle but have  to  do
       with  the  differences  between  DOS-format  file  times (always local time) and Unix-format times
       (always in GMT/UTC) and the necessity to compare the two.  A typical TZ value is  ``PST8PDT''  (US
       Pacific time with automatic adjustment for Daylight Savings Time or ``summer time'').