Test #2 Shell Programming

Part II Shell Programming - Points: 61  (13 of 25%)

Write code for an executable shell script named test2.sh that will do the
following actions, in the exact order given below.  Your test2.sh script
must follow the script writing guidelines and four-part error message
guidelines given in Notes file script_style.txt (and summarized in
script_checklist.txt).
If you don't know exactly how to implement a step, part marks may be given
for substitution of accurate PDL (written as shell comments) instead.

Summary and Purpose:
     The first argument to the script should be a Web URL.  The second,
     optional, argument is an integer count.  The script will fetch the
     raw URL and analyse the count of lines in the fetched URL file
     against the supplied count.

Only Step Comments are Required:
     Put only a one-line comment containing the step number in front of
     the executable code in each step (except the first step).  Do not put
     a Step Number comment as the first line of an executable script!

Submission of test2.sh :
     To submit your finished script, use this command:    ~alleni/bin/copy
     test2.sh
                   ________________________________________

  1.   [Points: 8] Start your script with a standard CST8129 script
       header; but, do not include the Purpose or Assignment Label
       sections.  (Remember the one-line description, syntax, path,
       collating, lang, and file creation mask.)  The file creation mask
       should block group write, block other read and write, and allow
       everything else.

  2.   [Points: 9] If the count of the number of arguments is incorrect,
       issue a good four-part error message about proper input and exit
       the script with status 1.

  3.   [Points: 1] Put the first command line argument (the URL) into a
       variable named url.

  4.   [Points: 2] Put a unique temporary file name (located in directory
       /tmp) into a variable named tmp. The unique file name must contain
       the current process ID number.

  5.   [Points: 9] Fetch from the Web the raw (unformatted) URL contained
       in the url variable, into the file named by the tmp variable.  If
       the fetching fails with a bad return status, issue a good error
       message, remove the file, and exit the script with status 2.

  6.   [Points: 8] Make sure the fetched URL file is not empty (has a file
       size larger than zero); otherwise, issue a good error message,
       remove the file, and exit the script with status 3.

  7.   [Points: 3] Remove group read permissions from the the file
       containing the fetched URL.  Do not change any other permissions.
       Quick-exit the script (no message) with status 4 if changing

       permissions fails.

  8.   [Points: 5] Put the count of the number of lines in the fetched URL
       file into a variable named urlcount. Quick-exit the script (no
       message) with status 5 on failure.

  9.   [Points: 4] If the number of command line arguments is two, put the
       optional second argument (the integer count) into a variable named
       count; otherwise, put the value 100 into that variable.

  10.  [Points: 7] Compare the value in urlcount against the value in
       count and select and display one of these two messages depending on
       the result:

            Your URL 'XXX' contains more than YYY lines: ZZZ.
            Your URL 'XXX' contains less than YYY lines: ZZZ.

       where XXX is replaced by the URL given by the user, YYY by the
       value of the count variable, and ZZZ by the actual count of the
       number of lines in the downloaded URL file.  Note that some URLs
       will result in no output at all.  The spelling and punctuation must
       be as shown above.

  11.  [Points: 5] Exit the script with status zero only if the number of
       lines in the fetched URL file equals the user-specified count;
       otherwise, remove the fetched URL file and exit with status 6.

Put a one-line comment containing only the step number in front of the
executable code in steps two and greater.