据我所知，在 C 中解析命令行参数的三种最流行的方法是:

To my knowledge, the three most popular ways how to parse command line arguments in C are:

• Getopt(#include 来自 POSIX C 库)，可以解决简单的参数解析任务.如果您对 bash 有点熟悉，那么 bash 的内置 getopt 是基于 GNU libc 的 Getopt.
• Argp(#include 来自 GNU C 库)，它可以解决更复杂的任务并照顾的东西，例如:
  • -?, --help 用于帮助信息，包括电子邮件地址
  • -V, --version 用于版本信息
  • --usage 用于使用信息
  • Getopt (#include <unistd.h> from the POSIX C Library), which can solve simple argument parsing tasks. If you're a bit familiar with bash, the getopt built-in of bash is based on Getopt from the GNU libc.
  • Argp (#include <argp.h> from the GNU C Library), which can solve more complex tasks and takes care of stuff like, for example:
    • -?, --help for help message, including email address
    • -V, --version for version information
    • --usage for usage message

    GNU C 库文档有一些很好的 Getopt 和 Argp 示例.

    The GNU C Library documentation has some nice examples for Getopt and Argp.

    • http://www.gnu.org/software/libc/手册/html_node/Getopt.html
    • http://www.gnu.org/software/libc/手册/html_node/Argp.html

    #include <stdbool.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <unistd.h>
    
    int main(int argc, char *argv[])
    {
        bool isCaseInsensitive = false;
        int opt;
        enum { CHARACTER_MODE, WORD_MODE, LINE_MODE } mode = CHARACTER_MODE;
    
        while ((opt = getopt(argc, argv, "ilw")) != -1) {
            switch (opt) {
            case 'i': isCaseInsensitive = true; break;
            case 'l': mode = LINE_MODE; break;
            case 'w': mode = WORD_MODE; break;
            default:
                fprintf(stderr, "Usage: %s [-ilw] [file...]
    ", argv[0]);
                exit(EXIT_FAILURE);
            }
        }
    
        // Now optind (declared extern int by <unistd.h>) is the index of the first non-option argument.
        // If it is >= argc, there were no non-option arguments.
    
        // ...
    }
    

    使用Argp的示例

    #include <argp.h>
    #include <stdbool.h>
    
    const char *argp_program_version = "programname programversion";
    const char *argp_program_bug_address = "<your@email.address>";
    static char doc[] = "Your program description.";
    static char args_doc[] = "[FILENAME]...";
    static struct argp_option options[] = { 
        { "line", 'l', 0, 0, "Compare lines instead of characters."},
        { "word", 'w', 0, 0, "Compare words instead of characters."},
        { "nocase", 'i', 0, 0, "Compare case insensitive instead of case sensitive."},
        { 0 } 
    };
    
    struct arguments {
        enum { CHARACTER_MODE, WORD_MODE, LINE_MODE } mode;
        bool isCaseInsensitive;
    };
    
    static error_t parse_opt(int key, char *arg, struct argp_state *state) {
        struct arguments *arguments = state->input;
        switch (key) {
        case 'l': arguments->mode = LINE_MODE; break;
        case 'w': arguments->mode = WORD_MODE; break;
        case 'i': arguments->isCaseInsensitive = true; break;
        case ARGP_KEY_ARG: return 0;
        default: return ARGP_ERR_UNKNOWN;
        }   
        return 0;
    }
    
    static struct argp argp = { options, parse_opt, args_doc, doc, 0, 0, 0 };
    
    int main(int argc, char *argv[])
    {
        struct arguments arguments;
    
        arguments.mode = CHARACTER_MODE;
        arguments.isCaseInsensitive = false;
    
        argp_parse(&argp, argc, argv, 0, 0, &arguments);
    
        // ...
    }
    

    自己动手的示例

    #include <stdbool.h>
    #include <stdio.h>
    #include <stdlib.h>
    
    int main(int argc, char *argv[])
    {   
        bool isCaseInsensitive = false;
        enum { CHARACTER_MODE, WORD_MODE, LINE_MODE } mode = CHARACTER_MODE;
        size_t optind;
        for (optind = 1; optind < argc && argv[optind][0] == '-'; optind++) {
            switch (argv[optind][1]) {
            case 'i': isCaseInsensitive = true; break;
            case 'l': mode = LINE_MODE; break;
            case 'w': mode = WORD_MODE; break;
            default:
                fprintf(stderr, "Usage: %s [-ilw] [file...]
    ", argv[0]);
                exit(EXIT_FAILURE);
            }   
        }
        argv += optind;
    
        // *argv points to the remaining non-option arguments.
        // If *argv is NULL, there were no non-option arguments.
    
        // ...
    }   
    

    免责声明:我是 Argp 的新手，该示例可能包含错误.

    Disclaimer: I am new to Argp, the example might contain errors.