thank me later

Inode Mode Mask Macro
set-user-ID 04000 S_ISUID
set-group-ID 02000 S_ISGID
sticky bit 01000 S_ISVTX
owner can read 00400 S_IRUSR
owner can write 00200 S_IWUSR
owner can execute 00100 S_IXUSR
group can read 00040 S_IRGRP
group can write 00020 S_IWGRP
group can execute 00010 S_IXGRP
other can read 00004 S_IROTH
other can write 00002 S_IWOTH
other can execute 00001 S_IXOTH