CSC2408: Software Development Tools- IT assignment

Internal Code- MAS3790

IT assignment

Software Development Tools aim is to give you a sound basic knowledge of the most important tools available under the Unix operating system. Question- Q1. Create a subdirectory in your home directory and put a file welcome.txt with a short message in this subdirectory. Try to: • set the permission bits so that the owner has executable access. • make the subdirectory the current directory; •list the subdirectory; • display the contents of welcome.txt; • create a copy of welcome.txt in the subdirectory. Repeat the experiment, but the owner has read access. Finally, answer the following questions. • If a directory has “read” permission bit, what operations can you perform on the the directory and/or the files in it? • If a directory has “executable” permission bit, what operations can you perform on the the directory and/or the files in it? Q2. Use examples to describe the differences in the substrings matched by the patterns which are specified by the following regular expressions. • ab.cd and ab*cd • ab.*cd and abb*cd • ^abc and ^abc$ • [abc]d and [^abc]d • [A-Z][_a-zA-Z0-9]* and [A-Z_][a-zA-Z0-9]* (Note the regular expression “x*$” could be described as a line has “zero or more x at the end of the line”.) Q3. Read find online manual page, then • Give the commandline of searching for all SUID and SGID programs in /usr/bin • Give the commandline of listing all the subdirectories in the current directory • Give the commandline of producing a long listing of all files in /usr/bin whose size are more than 750Kb.