From 0aae909742f0fcb9c2e25d1b5f8e1bf896acd430 Mon Sep 17 00:00:00 2001 From: Davis King Date: Sat, 6 Sep 2008 15:15:13 +0000 Subject: [PATCH] Added some comments to this example --HG-- extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%402499 --- examples/compress_stream_ex.cpp | 66 +++++++++++++++++++-------------- 1 file changed, 39 insertions(+), 27 deletions(-) diff --git a/examples/compress_stream_ex.cpp b/examples/compress_stream_ex.cpp index 94c6a1dec..e2517535c 100755 --- a/examples/compress_stream_ex.cpp +++ b/examples/compress_stream_ex.cpp @@ -28,18 +28,17 @@ #include #include #include -#include -// I am making a typedef for the verson of compress_stream I want to use. +// 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 verson of -// cmd_line_parser I want to use. I have selected print_1a_c, -// this is the version of kernel_1a that checks all its -// preconditions (i.e. the debugging version) and is -// extended by print_kernel_1. -typedef dlib::cmd_line_parser::print_1a_c clp; +// 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::check_1a_c clp; using namespace std; @@ -53,34 +52,57 @@ int main(int argc, char** argv) clp parser; cs compressor; - // first I will define the command line options I want + // 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 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"; - parser.print_options(cout); // this print_options() function is really - // convenient :) + // 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 he 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"); - if ((option_c.count() != 0 && option_d.count() != 0 ) || - (option_c.count() == 0 && option_d.count() == 0 ) ) + // 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; @@ -93,16 +115,10 @@ int main(int argc, char** argv) // check if the user told us the input file and if they did then // get the file name - if (option_in.count() == 1) + if (option_in) { in_file = option_in.argument(); } - else if (option_in.count() > 1) - { - cout << "Error in command line:\n You must specify only one input file.\n"; - cout << "\nTry the -h option for more information." << endl; - return 0; - } else { cout << "Error in command line:\n You must specify an input file.\n"; @@ -113,16 +129,10 @@ int main(int argc, char** argv) // check if the user told us the output file and if they did then // get the file name - if (option_out.count() == 1) + if (option_out) { out_file = option_out.argument(); } - else if (option_out.count() > 1) - { - cout << "Error in command line:\n You must specify only one output file.\n"; - cout << "\nTry the -h option for more information." << endl; - return 0; - } else { cout << "Error in command line:\n You must specify an output file.\n"; @@ -131,9 +141,11 @@ int main(int argc, char** argv) } + // 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";