<work>/postgresql-9.1.2
<orig>/postgresql-9.1.2
diff -urN <orig>/postgresql-9.1.2 <work>/postgresql-9.1.2 > patch_<projectname>_<projno>.txt where <projectname> is a meaningul abbreviation and <projno> is the project number (see the course home page).For example, "patch_matviews_15.txt"
<orig>/postgresql-9.1.2
patch -p1 < <path of the patch file>The argument following "p" is the number of leading directory names to be stripped to look for the file.