1 /* Arg_parser - POSIX/GNU command line argument parser. (C++ version) 2 Copyright (C) 2006-2021 Antonio Diaz Diaz. 3 4 This library is free software. Redistribution and use in source and 5 binary forms, with or without modification, are permitted provided 6 that the following conditions are met: 7 8 1. Redistributions of source code must retain the above copyright 9 notice, this list of conditions, and the following disclaimer. 10 11 2. Redistributions in binary form must reproduce the above copyright 12 notice, this list of conditions, and the following disclaimer in the 13 documentation and/or other materials provided with the distribution. 14 15 This library is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 18 */ 19 20 /* Arg_parser reads the arguments in 'argv' and creates a number of 21 option codes, option arguments, and non-option arguments. 22 23 In case of error, 'error' returns a non-empty error message. 24 25 'options' is an array of 'struct Option' terminated by an element 26 containing a code which is zero. A null name means a short-only 27 option. A code value outside the unsigned char range means a 28 long-only option. 29 30 Arg_parser normally makes it appear as if all the option arguments 31 were specified before all the non-option arguments for the purposes 32 of parsing, even if the user of your program intermixed option and 33 non-option arguments. If you want the arguments in the exact order 34 the user typed them, call 'Arg_parser' with 'in_order' = true. 35 36 The argument '--' terminates all options; any following arguments are 37 treated as non-option arguments, even if they begin with a hyphen. 38 39 The syntax for optional option arguments is '-<short_option><argument>' 40 (without whitespace), or '--<long_option>=<argument>'. 41 */ 42 43 class Arg_parser 44 { 45 public: 46 enum Has_arg { no, yes, maybe }; 47 48 struct Option 49 { 50 int code; // Short option letter or code ( code != 0 ) 51 const char * name; // Long option name (maybe null) 52 Has_arg has_arg; 53 }; 54 55 private: 56 struct Record 57 { 58 int code; 59 std::string argument; RecordRecord60 explicit Record( const int c ) : code( c ) {} RecordRecord61 explicit Record( const char * const arg ) : code( 0 ), argument( arg ) {} 62 }; 63 64 const std::string empty_arg; 65 std::string error_; 66 std::vector< Record > data; 67 68 bool parse_long_option( const char * const opt, const char * const arg, 69 const Option options[], int & argind ); 70 bool parse_short_option( const char * const opt, const char * const arg, 71 const Option options[], int & argind ); 72 73 public: 74 Arg_parser( const int argc, const char * const argv[], 75 const Option options[], const bool in_order = false ); 76 77 // Restricted constructor. Parses a single token and argument (if any). 78 Arg_parser( const char * const opt, const char * const arg, 79 const Option options[] ); 80 error()81 const std::string & error() const { return error_; } 82 83 // The number of arguments parsed. May be different from argc. arguments()84 int arguments() const { return data.size(); } 85 86 /* If code( i ) is 0, argument( i ) is a non-option. 87 Else argument( i ) is the option's argument (or empty). */ code(const int i)88 int code( const int i ) const 89 { 90 if( i >= 0 && i < arguments() ) return data[i].code; 91 else return 0; 92 } 93 argument(const int i)94 const std::string & argument( const int i ) const 95 { 96 if( i >= 0 && i < arguments() ) return data[i].argument; 97 else return empty_arg; 98 } 99 }; 100