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
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
/*
This is an example illustrating the use of the compress_stream and
cmd_line_parser components from the dlib C++ Library.
This example implements a simple command line compression utility.
The output from the program when the -h option is given is:
Usage: dclib_example (-c|-d) --in input_file --out output_file
Options:
-c Indicates that we want to compress a file.
-d Indicates that we want to decompress a file.
-h Display this help message.
--in <arg> This option takes one argument which specifies the
name of the file we want to compress/decompress.
--out <arg> This option takes one argument which specifies the
name of the output file.
*/
#include "dlib/compress_stream.h"
#include "dlib/cmd_line_parser.h"
#include <iostream>
#include <fstream>
#include <string>
// I am making a typedef for the version of compress_stream I want to use.
// I have selected kernel_1ec.
typedef dlib::compress_stream::kernel_1ec cs;
// Here I am making another typedef, this time for the version of
// cmd_line_parser I want to use. This version gives me a
// command line parser object that has all the available extensions
// for command line parsers applied to it. So I will be able to use
// its command line validation utilities as well as option printing.
typedef dlib::cmd_line_parser<char>::check_1a_c clp;
using namespace std;
using namespace dlib;
int main(int argc, char** argv)
{
try
{
clp parser;
cs compressor;
// first I will define the command line options I want.
// Add a -c option and tell the parser what the option is for.
parser.add_option("c","Indicates that we want to compress a file.");
parser.add_option("d","Indicates that we want to decompress a file.");
// add a --in option that takes 1 argument
parser.add_option("in","This option takes one argument which specifies the name of the file we want to compress/decompress.",1);
// add a --out option that takes 1 argument
parser.add_option("out","This option takes one argument which specifies the name of the output file.",1);
parser.add_option("h","Display this help message.");
// now I will parse the command line
parser.parse(argc,argv);
// Now I will use the parser to validate some things about the command line.
// If any of the following checks fail then an exception will be thrown and it will
// contain a message that tells the user what the problem was.
// First I want to check that none of the options were given on the command line
// more than once. To do this I define an array that contains the options
// that shouldn't appear more than once and then I just call check_one_time_options()
const char* one_time_opts[] = {"c", "d", "in", "out", "h"};
parser.check_one_time_options(one_time_opts);
// Here I'm checking that the user didn't pick both the c and d options at the
// same time.
parser.check_incompatible_options("c", "d");
// check if the -h option was given on the command line
if (parser.option("h"))
{
// display all the command line options
cout << "Usage: dclib_example (-c|-d) --in input_file --out output_file\n";
// This function prints out a nicely formatted list of
// all the options the parser has
parser.print_options(cout);
cout << endl;
return 0;
}
// Make some references to the options inside the parser. This is just
// for convenience so we don't have to type out the longer form below.
const clp::option_type& option_c = parser.option("c");
const clp::option_type& option_d = parser.option("d");
const clp::option_type& option_in = parser.option("in");
const clp::option_type& option_out = parser.option("out");
// make sure one of the c or d options was given
if (!option_c && !option_d)
{
cout << "Error in command line:\n You must specify either the c option or the d option.\n";
cout << "\nTry the -h option for more information." << endl;
return 0;
}
string in_file;
string out_file;
// check if the user told us the input file and if they did then
// get the file name
if (option_in)
{
in_file = option_in.argument();
}
else
{
cout << "Error in command line:\n You must specify an input file.\n";
cout << "\nTry the -h option for more information." << endl;
return 0;
}
// check if the user told us the output file and if they did then
// get the file name
if (option_out)
{
out_file = option_out.argument();
}
else
{
cout << "Error in command line:\n You must specify an output file.\n";
cout << "\nTry the -h option for more information." << endl;
return 0;
}
// open the files we will be reading from and writing to
ifstream fin(in_file.c_str(),ios::binary);
ofstream fout(out_file.c_str(),ios::binary);
// make sure the files opened correctly
if (!fin)
{
cout << "Error opening file " << in_file << ".\n";
return 0;
}
if (!fout)
{
cout << "Error creating file " << out_file << ".\n";
return 0;
}
// now perform the actual compression or decompression.
if (option_c)
{
compressor.compress(fin,fout);
}
else
{
compressor.decompress(fin,fout);
}
}
catch (exception& e)
{
// Note that this will catch any cmd_line_parse_error exceptions and print
// the default message.
cout << e.what() << endl;
}
catch (...)
{
cout << "Some error occurred" << endl;
}
}