miniopt

miniopt is a command line argument parser library for C/C++ language.

Features.

• Support C99 standard.
• Support GCC/MSVC/CLANG compiler.
• Can be no C library dependency.
• No third party dependencies.

Example

Here is a test example.

// test.c
#include "miniopt.h"
#include <stdio.h>

int main(int argc, char *argv[]) {
    option options[] = {
        {'a', "append", "<file>", "append file."},      // -a, --append
        {'r', "remove", "<file>", "remove file."},      // -r, --remove
        {'h', "help",   nil,      "show help."},        // -h, --help
        {nil, "debug",  nil,      "enable debug."},     //     --debug
        {'v', nil,      nil,      "show version with"   // -v
                                  "<br>comment line 2."
        }
    };
    const int optsum = sizeof(options) / sizeof(options[0]);

    if (miniopt.init(argc, (char **)argv, options, optsum) != 0) {
        printf("error: %s\n", miniopt.what());
        return 0;
    }

    int status;
    while ((status = miniopt.getopt()) > 0) {
        int id = miniopt.optind();
        switch (id) {
            case 0:    // -a, --append
            case 1:    // -r, --remove
            case 2:    // -h, --help
            case 3:    //     --debug
            case 4:    // -v
                printf("[option]\n  ");
                printf("optin-index = [%d] ", id);
                if (options[id].sname) {
                    printf("short-name = [%c]  ", options[id].sname);
                }
                if (options[id].lname) {
                    printf("long-name = [%s]  ", options[id].lname);
                }
                if (miniopt.optarg()) {
                    printf("opt-has-arg = [%s]", miniopt.optarg());
                }
                printf("\n");
                break;
            default:
                printf("[non-option-arg]\n  arg = [%s]\n", miniopt.optarg());
                break;
        }
    }

    if (status < 0) printf("error: %s\n", miniopt.what());

    printf("\nOptions:\n");
    miniopt.printopts(printf, 2);

    return status;
}

After compile the test, you can run the test by follow example commands.

> test -a key1 -akey2 -a=key3=value 
> test --append key1 --append=key2 --append=key3=value
> test xxx -r 123 yyy --remove 456 zzz
> test -v -vvv -vhv --debug
> test -a 123 -- -a 456 -v -vhv

How to build the library.

It is just a pair of file(miniopt.h and miniopt.c), and any C99 compiler ought to build it pass.

The library public APIs.

// Initialize miniopt.
int miniopt.init(int argc, char **argv, option *opts, int optsum);

// Get next option.
int miniopt.getopt();

// Get current option index.
int miniopt.optind();

// Get current option-argument or non-option-argument.     
const char* miniopt.optarg();

// Print options.
void miniopt.printopts(printf_fn printf_, int indention);

// Print any error.
const char* miniopt.what();

Support option features.

1. Short options that all have no arguments can concatenate with each other. For example:

   foo -a -b -c  
   foo -abc  
   

2. A short option that have an argument can concatenate with its argument. For example:

   foo -D _DEBUG
   foo -D=_DEBUG
   foo -D_DEBUG    ## If this option have both means of clause 1 and clause 2, 
                   ## this clause 2 will take effect first, so it won't be 
                   ## seen as "foo -D -_ -D -E -B -U -G".
   

3. A long option that have an argument can concatenate with its argument. For example:

   foo --define USING_DEBUG  
   foo --define=USING_DEBUG  
   

4. The token "--" is reserved as non option argument marker. it means all string(s) after which will be seen as non option argument(s). For example:

   $> rm -f       ## You can not delete a file name "-f" by this command,
   $> rm -- -f    ## but you can delete the file by this command.

The code generator

There is an experimental code generator can be used to generate the code automatically. You can run follow commands to build it, and the document is here.

> cmake -S . -B build
> cmake --build build

References

https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap12.html
https://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html
https://www.gnu.org/software/libc/manual/html_node/Getopt-Long-Options.html
https://linux.die.net/man/3/getopt_long
https://github.com/rpm-software-management/popt