Shell Programming and Scripting

S=($(ls a/* 2>/dev/null))                       # assign all source files to an array
T=(b c d e f)                                   # assing all target dirs to an array
for ((i=0; i<${#S[@]};i++))                     # let i run from 0 to # of source files
        do [ -z $(ls ${T[$i]}) ] &&             # test if target dir is empty
              { mv -v ${S[$i]} ${T[$i]} ||      # and move file (verbosely)
                     break                      # if move failed
              }
        done 2>/dev/null                        # redirect all error msgs to null