Accueil / Programmation / Programming Languages / C++ / Parsing C++ Command-Line Arguments

Parsing C++ Command-Line Arguments

Print Friendly, PDF & Email

Microsoft Specific

Microsoft C/C++ startup code uses the following rules when interpreting arguments given on the operating system command line:

  • Arguments are delimited by white space, which is either a space or a tab.
  • The caret character (^) is not recognized as an escape character or delimiter. The character is handled completely by the command-line parser in the operating system before being passed to the argv array in the program.
  • A string surrounded by double quotation marks (“string“) is interpreted as a single argument, regardless of white space contained within. A quoted string can be embedded in an argument.
  • A double quotation mark preceded by a backslash (“) is interpreted as a literal double quotation mark character (“).
  • Backslashes are interpreted literally, unless they immediately precede a double quotation mark.
  • If an even number of backslashes is followed by a double quotation mark, one backslash is placed in the argv array for every pair of backslashes, and the double quotation mark is interpreted as a string delimiter.
  • If an odd number of backslashes is followed by a double quotation mark, one backslash is placed in the argv array for every pair of backslashes, and the double quotation mark is “escaped” by the remaining backslash, causing a literal double quotation mark (“) to be placed in argv.
Example

The following program demonstrates how command-line arguments are passed:

// command_line_arguments.cpp
// compile with: /EHsc
#include <iostream>

using namespace std;
int main( int argc,      // Number of strings in array argv
          char *argv[],   // Array of command-line argument strings
          char *envp[] )  // Array of environment variable strings
{
    int count;

    // Display each command-line argument.
    cout << "nCommand-line arguments:n";
    for( count = 0; count < argc; count++ )
         cout << "  argv[" << count << "]   "
                << argv[count] << "n";
}

Xem nguồn tại MSDN.

À propos Nguyen Vu Ngoc Tung

I love making new professional acquaintances. Don't hesitate to contact me via nguyenvungoctung@gmail.com if you want to talk about information technology, education, and research on complex networks analysis (i.e., metabolic networks analysis), data analysis, and applications of graph theory. Specialties: researching and proposing innovative business approaches to organizations, evaluating and consulting about usability engineering, training and employee development, web technologies, software architecture.

Laisser une réponse

Votre adresse email ne sera pas publiéeLes champs requis sont surlignés *

*

Ce site utilise Akismet pour réduire les indésirables. En savoir plus sur comment les données de vos commentaires sont utilisées.