Ace_get_opt parsing the command line

Ace_get_opt is an iterator that parses command-line parameter options.

1: Construction method

Ace_get_opt needs to refer to the header file, #include "Ace/get_opt.h".

ace_get_opt (int  argc,               * *argv               ,const Ace_tchar *optstring = Ace_text ( "" ),               int1,               int0,               int ordering = Permute_args,               int0);

　　

argc and argv are the parameters of the program entry function Main method, which is the command line of the program.

optstring is a specified parameter option, and is a character as an option, consisting mainly of three forms

• A simple character option, such as S, that indicates that an option cannot be added after this option
• A character option followed by a colon, such as S:, indicates that there will be a parameter after this option
• A character followed by two colons, such as S::, indicating that this option can have parameters or no parameters

Skip_args means starting with the first element of argv, the default is 1, and generally argv[0] is the path of the program

report_errors Whether an error is indicated when an unrecognized parameter is encountered

long_only Indicates whether to include only the option parameters of the string.

The following explains the character options and string options, that is, short option and long option.

• Short option starts with the character '-', such as-s
• long option starts with two characters '-', than into--server

This is in the case of the default, which is Long_only = 0. And when long_only is not equal to 0, you can use-server to represent long option.

2: Operation

Traversing the command line to take out a parameter item depends on 2 basic operations

   /*    * Scan elements of @a argv (whose length is @a argc) for short option   * characters given in @a optstring or L Ong options (with no short   * option equivalents).    */   int operator () (void);    /*    * For communication from @c operator () to the caller.  When   * @c operator () finds a option that takes a argument, the argument   * value is returned from this method, Otherwise it returns 0.    */ *opt_arg (voidconst;   

int operator () (void), used to traverse a parameter item

The opt_arg is used to remove the value of the parameter entry.

3: Sample Program

Command-line arguments: ACE_TEST.EXE-E 2000-i 1000

#include"ace/get_opt.h"#include"ace/os_ns_unistd.h"#include"ace/os_ns_sys_time.h"#include<iostream>ConstAce_time_value Max_interval ( -* -);intMainintargcChar**argv) {Ace_time_value Expiration=Ace_os::gettimeofday ();    Ace_time_value interval; Ace_get_opt Opt (ARGC,ARGV,"e:i:");  for(intc = (c = opt ())! =-1;) {        Switch(c) { Case 'e': Expiration + =Ace_time_value (Atoi (Opt.opt_arg ()));  Break;  Case 'I': Interval =Ace_time_value (Atoi (Opt.opt_arg ()));  Break; }    }    if(Interval >max_interval) {cout<<"interval must is less than"<<max_interval.sec () <<Endl; }    Else if(Expiration > (Ace_time_value::max_time-interval)) {cout<<"expiration + interval must is less than"<<ace_time_value::max_time.sec () <<Endl; }    return 0; }

Partially reproduced from http://www.cnblogs.com/hbccdf/p/use_acegetopt_parse_commandline.html.

Ace_get_opt parsing the command line