GNU argp "too few arguments"
GNU argp "too few arguments"
我的程序应该接受两个必需的参数和三个可选参数,如下
ATE <input file> <output file> [--threads] [--bass] [--treble]
(注意,我还没有弄清楚如何使用<required>
参数,所以输入和输出文件在代码中定义为-I input_file和-o output_file)
我使用GNU库argp来解析命令行参数,我的文件基于第三个示例。
我使用以下命令运行程序
$ ./ATE -i input_file.pcm -o output_file.pcm
Too few arguments!
Usage: ATE [OPTION...]
-p AMOUNT_OF_THREADS -b BASS_INTENSITY -t TREBLE_INTENSITY
input_file.pcm output_file.pcm
Try `ATE --help' or `ATE --usage' for more information.
threads: 2, bass: 4, treble: 4
opening file input.pcm
RUNNING!
done, saving to out.pcm
当运行我的程序时,我得到了"太少的参数",即使argp成功地解析了输入和输出选项,正如你在输出中看到的那样。
cout << state->arg_num << endl;
打印出parse_opt中的参数数量,在每次调用时给我0。
代码有点长,但它是完全自包含的,所以您可以编译它来自己查看。
commands.cpp使用命名空间std;
#include <stdlib.h>
#include <argp.h>
#include <iostream>
#include <string>
#include <errno.h>
struct arguments {
string input_file;
string output_file;
int threads;
int bass;
int treble;
};
static char doc[] = "Parallequaliser - a multithreaded equaliser application written in c++";
static char args_doc[] = "-p AMOUNT_OF_THREADS -b BASS_INTENSITY -t TREBLE_INTENSITY input_file.pcm output_file.pcm";
static struct argp_option options[] = {
{"input_file", 'i', "IN_FILE", 0, "an input file in pcm format"},
{"output_file", 'o', "OUT_FILE", 0, "an output file in pcm format"},
{"threads", 'p', "AMOUNT_OF_THREADS", OPTION_ARG_OPTIONAL, "amount of threads, min 2"},
{"bass", 'b', "BASS_INTENSITY", OPTION_ARG_OPTIONAL, "bass intensity, from 0 to 7"},
{"treble", 't', "TREBLE_INTENSITY", OPTION_ARG_OPTIONAL, "treble intensity, from 0 to 7"},
{0}
};
static error_t parse_opt (int key, char *arg, struct argp_state *state) {
struct arguments *arguments = (struct arguments *) state->input;
switch (key) {
case 'p':
if (arg == NULL) {
arguments->threads = 4;
} else {
arguments->threads = strtol(arg, NULL, 10);
}
break;
case 'b':
if (arg == NULL) {
arguments->bass = 4;
} else {
arguments->bass = strtol(arg, NULL, 10);
}
break;
case 't':
if (arg == NULL) {
arguments->treble = 4;
} else {
arguments->treble = strtol(arg, NULL, 10);
}
break;
case 'i':
if (arg == NULL) {
cout << "You forgot to specify the input file using the -i input_file.pcm option" << endl;
} else {
arguments->input_file = (string) arg;
}
break;
case 'o':
if (arg == NULL) {
cout << "You forgot to specify the out file using the -i output_file.pcm option" << endl;
} else {
arguments->output_file = (string) arg;
}
break;
case ARGP_KEY_ARG:
cout << "Key arg... " << key << endl;
if (state->arg_num > 5){
cout << "Too many arguments!" << endl;
argp_usage(state);
}
break;
case ARGP_KEY_END:
if (state->arg_num < 2){
cout << "Too few arguments!" << endl;
argp_usage(state);
}
break;
default:
return ARGP_ERR_UNKNOWN;
}
return 0;
}
static struct argp argp = { options, parse_opt, args_doc, doc };
int main (int argc, char **argv) {
struct arguments arguments;
arguments.threads = 2;
arguments.bass = 4;
arguments.treble = 4;
argp_parse(&argp, argc, argv, ARGP_NO_EXIT, 0, &arguments);
cout << "threads: " << arguments.threads << ", bass: " << arguments.bass << ", treble: " << arguments.treble << endl;
cout << "opening file " << arguments.input_file << endl;
cout << "RUNNING!" << endl;
cout << "done, saving to " << arguments.output_file << endl;
return 0;
}
这些选项不算作argp解析器上下文的"参数"。
当运行./ATE -i input_file.pcm -o output_file.pcm
时,您的参数"太少",因为您到达了参数的末尾ARGP_KEY_END
,而没有留下任何参数。arg_num
表示"独立"参数:已处理的ARGP_KEY_ARG
参数的数量。你没有。
为了确保您拥有最初想要的两个必需参数,请检查您是否在没有看到两个参数的情况下到达ARGP_KEY_END
(就像您已经在做的那样:参数太少意味着您没有两个文件名)。case ARGP_KEY_ARG
是获取参数值的地方。
相关文章:
- 具有变量Number of Arguments的std::函数的矢量
- 如何修复"too few arguments to function"?
- 开放CV垫"Sizes of input arguments do not match"的问题
- 有没有办法在初始化字符串时避免来自 clang-tidy(fuchsia-default-arguments)的警告?
- glGenVertexArrays and glGenBuffers arguments
- 'type_alias<char[N]>{}' VS 'char[N]{}' in function's arguments
- Command Line Arguments wxCmdLineArgsArray in wxWidgets
- OpenCV std::vector for cv::Mat arguments
- map.insert:"Invalid arguments"错误与 pair<enum,vector<*>>
- VS说"Too few arguments...",但其他编译器给了我正确的输出?
- Win32 CreateThread() Arguments Zero'ed?
- Eclipse CDT - 使用模板默认值时的"Invalid arguments"
- "All arguments to functions are passed by value" C 中的,C++ 中对引用传递的混淆
- std::result_of for lvalue/rvalue arguments
- RPC:xdr_bytes "Can't encode arguments"当阵列太大时
- 是“ Gnu-Zero-variadic-Macro-arguments”可靠地忽略
- 如何修复("too few arguments in function call")?
- GNU argp "too few arguments"
- 提升线程中的"too few arguments to function"
- SQL Server 连接字符串"To few arguments"