want to do : cp ../experimental_structures/sys_1_aaa.pdb ./sys_1 $sysnum is a variable cp ../experimental_structures/sys_"$sysnum"_*.pdb ./sys_$sysnum
want to do : cp ../experimental_structures/sys_1_aaa.pdb ./sys_1 $sysnum is a variable cp ../experimental_structures/sys_"$sysnum"_*.pdb ./sys_$sysnum