help to explain the shell code !
 

GCC_INCLUDEDIR=`dirname $(gcc -print-libgcc-file-name)`/include &&
find ${GCC_INCLUDEDIR}/* -maxdepth 0 -xtype d -exec rm -rvf '{}' \; &&
rm -vf `grep -l "DO NOT EDIT THIS FILE" ${GCC_INCLUDEDIR}/*` &&
unset GCC_INCLUDEDIR


the above code are from LFS BOOK.
I cann't understand the red line .
this:
find ${GCC_INCLUDEDIR}/* -maxdepth 0 -xtype d -exec rm -rvf '{}' \; &&

especially the \;


and what is the differeces between && and /?

Thank you !

Try reading the man page for find.

First you're finding the directory with gcc headers. Then you're looking in that directory for subdirectories But not entering those subdirectories For any subdirectories found you're removing them && means continue with the next command if the previous command exits with code 0 (i.e., successfully). The / depends on context. In this case, it is the path separator.