task-printer/5.txt at master · oliverstivers/task-printer · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
<!DOCTYPE html>
<html>

  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">

    <!-- Edit page title -->
    <title>CSE 333 25au Exercise 6</title>

    <link href='https://fonts.googleapis.com/css?family=Source+Sans+Pro:400,400italic,600' rel='stylesheet' type='text/css'>
    <link href='https://fonts.googleapis.com/css?family=Inconsolata:400,700' rel='stylesheet' type='text/css'>

    <!-- This script dynamically loads CSS and JS files from the course base directory -->
    <!-- Only edit if you want to change the paths to your JS/CSS sources -->
    <script>
      // Get the base path for the course web by extracting 'courses' + courseName + quarter
      var fullPathArray = window.location.pathname.split('/');
      var basePathArray = fullPathArray.slice(0,4);
      var basePath = basePathArray.join('/');

      // CSS files to load
      var cssSources = [
        '/site/css/bootstrap.min.css',
        '/site/css/main.css',
      ];

      // Javscript files to load
      var jsSources = [
        '/site/js/jquery.min.js',
        '/site/js/bootstrap.min.js',
        '/site/js/nav-bar.js',
        '/site/js/footer.js'
      ];

      // Include the script that will load the CSS & Javscript files
      document.write("<script src=\'" + basePath + "/site/js/load-sources.js\'><\/script>");
    </script>

  </head>

  <body>
    <header class="site-header">
    <!-- Javascript will load the navigation bar code here. -->
    </header>

    <div class="container">

      <!-- Begin page content -->

      <h1>CSE 333 25au Exercise 6</h1>

<p>
<b>out:</b> Monday, October 6, 2025<br>
 <b>due:</b> Wednesday, October 8, 2025 by <b>10:00 am</b>,
 <b>No late exercises accepted</b>.
</p>


<p><b>Goals: </b>Learn how to use various parts of the standard C file I/O
library, particularly ones that will be needed on later projects.  Also reenforce
understanding of exactly what is in a file that is stored on the disk.</p>

  <p><b>Description: </b>
     Write a C program that accepts a filename as a single
     command-line argument.  The program should read the file,
     copying the contents of the file to <code>stdout</code> in reverse order, character
     by character (or, more precisely, byte by byte).
     </p>

     <p>
     For example, consider a file name <code>foo.txt</code> in the
     current directory that contains the
     following 7 bytes (the 7th byte is the newline character at the end):
     <blockquote><pre>hello!
</pre></blockquote>
     Running the program should result in the following:
     <blockquote><pre>
<b>bash$</b> ./ex6 foo.txt

!olleh<b>bash$</b></pre></blockquote>
     Pay careful attention to where the newline and other characters
     are in this output.<br>
     </p>

	<p>You will need to use several standard library calls in order to
       do this.  In particular, you should use:
       <ul>
         <li> <code>fopen</code>, with mode "rb", to open the file</li>
         <li> <code>fclose</code> to close the file</li>
         <li> <code>fseek</code> and <code>ftell</code> to figure out
           how large the file is.  (We'd suggest you
           <code>fseek(f, 0, SEEK_END);</code> and then <code>size =
             ftell(f);</code> to get the file size, in bytes.)</li>
         <li> <code>fseek</code> and <code>fread</code> to read the
           file's contents, in reverse order, byte-by-byte.</li>
         <li> <code>printf</code>, with the <code>%c</code> format code, to print out the
           characters (bytes) of the file one at a time.</li>
       </ul>
       </p>

    <p>Your code should read the bytes one-at-a-time and print them
    immediately.  Do not read the entire file into memory and print it
    backwards or create a reversed copy of the data and print that. A goal
    of this exercise is to gain experience with the various file I/O
    functions described above.</p>

	<p>Remember to consult the
       <a href="http://www.cplusplus.com/reference/">C/C++ Reference Material</a>
       and <a href="https://man7.org/linux/man-pages/index.html">Linux manual pages</a>
       to learn how to use each of these functions. (Check
       out the <code>stdio.h</code> header)</p>

	<p>Note: Some of these library functions are quite old and have parameters or results
	whose type is <code>long</code>.  Style guides and programs like
	<code>cpplint</code> generally discourage using <code>long</code>
	and recommend using types like <code>int64_t</code> instead.
	But for these library functions it's appropriate
	to use variables of type <code>long</code> to match function
	parameter and result types, since that guarantees an exact match
	regardless of the exact size of <code>long</code> on the underlying
	machine.  Feel free to ignore any <code>cpplint</code>
	warnings about using <code>long</code> in these situations.</p>

	<p>Hint: you can use linux commands like <code>hexdump -C foo.txt</code> or
	<code>hexdump -c foo.txt</code> to look at the bytes in a file <code>foo.txt</code>
	in hex and in other formats
	to see exactly what's there, including invisible characters.
	Many text editors also have modes to do this.</p>

  <p>

  <hr>
  <p>Your code must:
  <ul>
    <li> compile without errors or warnings on CSE Linux machines
	(lab workstations, attu, or CSE home VM)</li>

    <li> have no crashes, memory leaks, or memory errors on CSE linux machines
    (Suggestion: <code>valgrind</code>)</li>

    <li> be contained in a single file called <code>ex6.c</code>
    that compiles with the command <code>gcc -Wall -g -std=c17 -o ex6 ex6.c</code> -- do
    not submit a Makefile.</li>

    <li> be pretty: the formatting, modularization, variable and
    function names, and so on must make us smile rather than cry.
    (Suggestion: <code>cpplint --clint</code>)
	</li>

    <li> be robust: you should think about handling bogus input
    from the user (if any), and you should handle hard-to-handle cases
    (if there are any) gracefully.</li>

    <li> have a comment at the top of the source file with your name,
    and CSE or UW email address.</li>
  </ul>
  <p>

  <p>
  You should submit your exercise using the Gradescope dropbox linked on the
course resources web page.</p>


      <!-- End page content -->

    </div>

    <footer class="site-footer">
    <!-- Javascript will load the footer code here. -->
    </footer>

  </body>

</html>