The OpenNET Project / Index page

[ новости /+++ | форум | теги | ]

Интерактивная система просмотра системных руководств (man-ов)

 ТемаНаборКатегория 
 
 [Cписок руководств | Печать]

getopt_long (3)
  • getopt_long (3) ( Solaris man: Библиотечные вызовы )
  • >> getopt_long (3) ( FreeBSD man: Библиотечные вызовы )
  • getopt_long (3) ( Русские man: Библиотечные вызовы )
  • getopt_long (3) ( Linux man: Библиотечные вызовы )

  • BSD mandoc
     

    NAME

    
    
    getopt_long
    
     
    getopt_long_only
    
     - get long options from command line argument list
    
     
    

    LIBRARY

    Lb libc
    
     
    

    SYNOPSIS

       #include <getopt.h>
    Vt extern char *optarg ; Vt extern int optind ; Vt extern int optopt ; Vt extern int opterr ; Vt extern int optreset ; int Fo getopt_long Fa int argc char * const *argv const char *optstring Fa const struct option *longopts int *longindex Fc Ft int Fo getopt_long_only Fa int argc char * const *argv const char *optstring Fa const struct option *longopts int *longindex Fc  

    DESCRIPTION

    The getopt_long ();
    function is similar to getopt(3) but it accepts options in two forms: words and characters. The getopt_long ();
    function provides a superset of the functionality of getopt(3). The getopt_long ();
    function can be used in two ways. In the first way, every long option understood by the program has a corresponding short option, and the option structure is only used to translate from long options to short options. When used in this fashion, getopt_long ();
    behaves identically to getopt(3). This is a good way to add long option processing to an existing program with the minimum of rewriting.

    In the second mechanism, a long option sets a flag in the Vt option structure passed, or will store a pointer to the command line argument in the Vt option structure passed to it for options that take arguments. Additionally, the long option's argument may be specified as a single argument with an equal sign, e.g.,

    "myprogram --myoption=somevalue"

    When a long option is processed, the call to getopt_long ();
    will return 0. For this reason, long option processing without shortcuts is not backwards compatible with getopt(3).

    It is possible to combine these methods, providing for long options processing with short option equivalents for some options. Less frequently used options would be processed as long options only.

    The getopt_long ();
    call requires a structure to be initialized describing the long options. The structure is:

    struct option {
            char *name;
            int has_arg;
            int *flag;
            int val;
    };
    

    The name field should contain the option name without the leading double dash.

    The has_arg field should be one of:

    no_argument
    no argument to the option is expect
    required_argument
    an argument to the option is required
    optional_argument
    an argument to the option may be presented.

    If flag is not NULL then the integer pointed to by it will be set to the value in the val field. If the flag field is NULL then the val field will be returned. Setting flag to NULL and setting val to the corresponding short option will make this function act just like getopt(3).

    If the Fa longindex field is not NULL then the integer pointed to by it will be set to the index of the long option relative to Fa longopts .

    The last element of the Fa longopts array has to be filled with zeroes.

    The getopt_long_only ();
    function behaves identically to getopt_long ();
    with the exception that long options may start with `-' in addition to `--' If an option starting with `-' does not match a long option but does match a single-character option, the single-character option is returned.  

    RETURN VALUES

    If the Fa flag field in Vt struct option is NULL getopt_long ();
    and getopt_long_only ();
    return the value specified in the Fa val field, which is usually just the corresponding short option. If Fa flag is not NULL these functions return 0 and store Fa val in the location pointed to by Fa flag . These functions return `:' if there was a missing option argument, `?' if the user specified an unknown or ambiguous option, and -1 when the argument list has been exhausted.  

    ENVIRONMENT

    POSIXLY_CORRECT
    If set, option processing stops when the first non-option is found and a leading `-' or `+' in the Fa optstring is ignored.

     

    EXAMPLES

    int bflag, ch, fd;
    int daggerset;
    
    /* options descriptor */
    static struct option longopts[] = {
            { "buffy",      no_argument,            NULL,           'b' },
            { "fluoride",   required_argument,      NULL,           'f' },
            { "daggerset",  no_argument,            Am]daggerset,   1 },
            { NULL,         0,                      NULL,           0 }
    };
    
    bflag = 0;
    while ((ch = getopt_long(argc, argv, "bf:", longopts, NULL)) != -1)
            switch (ch) {
            case 'b':
                    bflag = 1;
                    break;
            case 'f':
                    if ((fd = open(optarg, O_RDONLY, 0)) == -1)
                            err(1, "unable to open %s", optarg);
                    break;
            case 0:
                    if (daggerset) {
                            fprintf(stderr,"Buffy will use her dagger to "
                                "apply fluoride to dracula's teeth\n");
                    }
                    break;
            default:
                    usage();
    }
    argc -= optind;
    argv += optind;
    
     

    IMPLEMENTATION DIFFERENCES

    This section describes differences to the GNU implementation found in glibc-2.1.3:

     

    SEE ALSO

    getopt(3)  

    HISTORY

    The getopt_long ();
    and getopt_long_only ();
    functions first appeared in GNU libiberty. The first BSD implementation of getopt_long ();
    appeared in Nx 1.5 , the first BSD implementation of getopt_long_only ();
    in Ox 3.3 . Fx first included getopt_long ();
    in Fx 5.0 , getopt_long_only ();
    in Fx 5.2 .  

    BUGS

    The Fa argv argument is not really Vt const as its elements may be permuted (unless POSIXLY_CORRECT is set).

    The implementation can completely replace getopt(3), but right now we are using separate code.


     

    Index

    NAME
    LIBRARY
    SYNOPSIS
    DESCRIPTION
    RETURN VALUES
    ENVIRONMENT
    EXAMPLES
    IMPLEMENTATION DIFFERENCES
    SEE ALSO
    HISTORY
    BUGS


    Поиск по тексту MAN-ов: 




    Партнёры:
    PostgresPro
    Inferno Solutions
    Hosting by Hoster.ru
    Хостинг:

    Закладки на сайте
    Проследить за страницей
    Created 1996-2024 by Maxim Chirkov
    Добавить, Поддержать, Вебмастеру