C ++：如何检查文件的类型，而扩展 [英] C++: How to check type of files without extension

问题描述

我使用boost ::文件系统中的目录搜索和处理文件。
但是，而不是处理的每一个文件我想只处理的文本文件（通过使用boost ::文件系统:: is_regular_file（）检查）（或至少忽略二进制文件）。

I am using boost::filesystem to search and process files in a directory. But instead of processing every file (checked by using boost::filesystem::is_regular_file()) I want to only process text files (or at least ignore binary files).

有没有一种方法，我怎么能做到这一点，即使文件的不具有扩展

Is there a way how I can achieve that even if files do not have an extension?

我会强烈AP preciate一个独立于平台的解决方案。

I would highly appreciate a platform independent solution.

推荐答案

使用 libmagic

Libmagic可在所有主要平台（和许多未成年人）。

Libmagic is available on all major platforms (and many minors).

#include <boost/filesystem.hpp>
#include <boost/range.hpp>
#include <iostream>
#include <magic.h>

using namespace boost;
namespace fs = filesystem;

int main() {
    auto handle = ::magic_open(MAGIC_NONE|MAGIC_COMPRESS);
    ::magic_load(handle, NULL);

    for (fs::directory_entry const& x : make_iterator_range(fs::directory_iterator("."), {})) {
        auto type = ::magic_file(handle, x.path().native().c_str());
        std::cout << x.path() << "\t" << (type? type : "UNKOWN") << "\n";
    }

    ::magic_close(handle);
}

打印，例如

sehe@desktop:~/custom/boost/status$ /tmp/test 
"./Jamfile.v2"  ASCII text
"./explicit-failures.xsd"   XML document text
"./expected_results.xml"    XML document text
"./explicit-failures-markup.xml"    XML document text

您可以使用该标志来控制分类的细节，例如MAGIC_MIME：

You can use the flags to control the detail of classification, e.g. MAGIC_MIME:

sehe@desktop:~/custom/boost/status$ /tmp/test 
"./Jamfile.v2"  text/plain; charset=us-ascii
"./explicit-failures.xsd"   application/xml; charset=us-ascii
"./expected_results.xml"    application/xml; charset=us-ascii
"./explicit-failures-markup.xml"    application/xml; charset=utf-8

或加载刚的/ etc /魔术：

sehe@desktop:~/custom/boost/status$ /tmp/test 
"./Jamfile.v2"  ASCII text
"./explicit-failures.xsd"   ASCII text
"./expected_results.xml"    ASCII text, with very long lines
"./explicit-failures-markup.xml"    UTF-8 Unicode text

这篇关于C ++：如何检查文件的类型，而扩展的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！