16.3. Getting the Source
  The
  
   PostgreSQL
  
  13.15 sources can be obtained from the
   download section of our
   website:
  
   https://www.postgresql.org/download/
  
  .  You
   should get a file named
  
   postgresql-13.15.tar.gz
  
  or
  
   postgresql-13.15.tar.bz2
  
  . After
   you have obtained the file, unpack it:
 
gunzip postgresql-13.15.tar.gztar xf postgresql-13.15.tar
  (Use
  
   bunzip2
  
  instead of
  
   gunzip
  
  if
   you have the
  
   .bz2
  
  file.  Also, note that most
   modern versions of
  
   tar
  
  can unpack compressed archives
   directly, so you don't really need the
   separate
  
   gunzip
  
  or
  
   bunzip2
  
  step.)
   This will create a directory
  
   postgresql-13.15
  
  under the current directory
   with the
  
   PostgreSQL
  
  sources.
   Change into that directory for the rest
   of the installation procedure.
 
You can also get the source directly from the version control repository, see Appendix I .