From: http://www.csdn.net/article/2013-08-07/2816477-6-source-code-search-engines-you-can-use-for-programming-projects
Next we will introduce 6 source code search engines to help you find the source code that is more suitable for you.
1. ohloh
Ohloh code is the largest and comprehensive source code search engine. According to the FOSS directory, it has more than 1 billion linesCodeIt is constantly updated. It is not only free, but also available throughCommunityFor free editing. All text files can be indexed by searching, and 43 typesProgramming LanguageAll have the syntax prompt function. In addition, the search syntax is flexible and you can find different types of classes. Search engines currently do not support regular expressions.
2. krugle
Krugle is an open-source search portal.Source codeAre included, such as Apache, javadocs, and SourceForge. You can also search for code written in C ++, Java, Perl, SQL, Ruby, XML, HTML, and other languages. Krugle also provides a very advanced search function to help you quickly locate the correct API, library, sample code, or documentation. On the search results page, you can directly browse the project source code.
3. searchcode
Searchcode filters nearly 16 billion lines of open source code from code repositories such as GitHub, Bitbucket, codeplex, SourceForge, and fedora. The code and documentation are maintained by a separate developer. You can use filters such as file extension, specific code library name, URL, regular expression, and special characters to filter the source code so that you can find the desired code. For more information, see the example.
4. nerdydata
Nerdydata.com is a search engine that can search the content in the source code of a webpage. It already has more than 1.4 million web code indexes. If you are a web developer, you can search for HTML Tag, JavaScript code, or CSS style code snippet. The goal of nerdydata is not only to build a simple source code search engine, but also to develop a series of functions around the web development process.
5. symbol hound
When it comes to searching for special symbols, Google and other search engines are not the best choice. For example, Google removes many punctuation marks and special symbols. If you want to search for variables and error codes containing special characters, using a common search engine may not return the expected results. The emergence of symbol hound solves this problem.
6. merobase
Unlike other search engines, merobase is not used to search for source code, but to search for and locate software components. It can search for components written in Java, C ++, C #, and other languages. Merobase can also search for simple text Interfaces Based on queries. You can also search for functions, object-oriented queries, names, and test-driven queries. This is also a highlight of merobase.