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-rw-r--r-- | arg_parser.h | 110 |
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diff --git a/arg_parser.h b/arg_parser.h new file mode 100644 index 0000000..1eeec9a --- /dev/null +++ b/arg_parser.h @@ -0,0 +1,110 @@ +/* Arg_parser - POSIX/GNU command-line argument parser. (C++ version) + Copyright (C) 2006-2024 Antonio Diaz Diaz. + + This library is free software. Redistribution and use in source and + binary forms, with or without modification, are permitted provided + that the following conditions are met: + + 1. Redistributions of source code must retain the above copyright + notice, this list of conditions, and the following disclaimer. + + 2. Redistributions in binary form must reproduce the above copyright + notice, this list of conditions, and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. +*/ + +/* Arg_parser reads the arguments in 'argv' and creates a number of + option codes, option arguments, and non-option arguments. + + In case of error, 'error' returns a non-empty error message. + + 'options' is an array of 'struct Option' terminated by an element + containing a code which is zero. A null long_name means a short-only + option. A code value outside the unsigned char range means a long-only + option. + + Arg_parser normally makes it appear as if all the option arguments + were specified before all the non-option arguments for the purposes + of parsing, even if the user of your program intermixed option and + non-option arguments. If you want the arguments in the exact order + the user typed them, call 'Arg_parser' with 'in_order' = true. + + The argument '--' terminates all options; any following arguments are + treated as non-option arguments, even if they begin with a hyphen. + + The syntax for optional option arguments is '-<short_option><argument>' + (without whitespace), or '--<long_option>=<argument>'. +*/ + +class Arg_parser + { +public: + enum Has_arg { no, yes, maybe }; + + struct Option + { + int code; // Short option letter or code ( code != 0 ) + const char * long_name; // Long option name (maybe null) + Has_arg has_arg; + }; + +private: + struct Record + { + int code; + std::string parsed_name; + std::string argument; + explicit Record( const unsigned char c ) + : code( c ), parsed_name( "-" ) { parsed_name += c; } + Record( const int c, const char * const long_name ) + : code( c ), parsed_name( "--" ) { parsed_name += long_name; } + explicit Record( const char * const arg ) : code( 0 ), argument( arg ) {} + }; + + const std::string empty_arg; + std::string error_; + std::vector< Record > data; + + bool parse_long_option( const char * const opt, const char * const arg, + const Option options[], int & argind ); + bool parse_short_option( const char * const opt, const char * const arg, + const Option options[], int & argind ); + +public: + Arg_parser( const int argc, const char * const argv[], + const Option options[], const bool in_order = false ); + + // Restricted constructor. Parses a single token and argument (if any). + Arg_parser( const char * const opt, const char * const arg, + const Option options[] ); + + const std::string & error() const { return error_; } + + // The number of arguments parsed. May be different from argc. + int arguments() const { return data.size(); } + + /* If code( i ) is 0, argument( i ) is a non-option. + Else argument( i ) is the option's argument (or empty). */ + int code( const int i ) const + { + if( i >= 0 && i < arguments() ) return data[i].code; + else return 0; + } + + // Full name of the option parsed (short or long). + const std::string & parsed_name( const int i ) const + { + if( i >= 0 && i < arguments() ) return data[i].parsed_name; + else return empty_arg; + } + + const std::string & argument( const int i ) const + { + if( i >= 0 && i < arguments() ) return data[i].argument; + else return empty_arg; + } + }; |