C++編寫的用于去除C、C++、Java等語言的注釋的代碼片段

// author :Rohith Gowda
// - remove C/C++ comments
// - assume no nested block comments

// Modifications
include<iostream>
include<fstream>
using namespace std;
void parse(ifstream &fin , ofstream &fout)
{
    char curr, prev = '\0';
    bool comment = false;
    bool charLiteral = false;
    bool stringLiteral = false;

while (fin.get(curr)) {
    if (charLiteral) {
        fout << curr;
        if (curr == '\'' && prev != '\\') { // 'a' ends
            charLiteral = false;
        }
        prev = (prev == '\\' && curr == '\\') ? '\0' : curr;
    } else if (stringLiteral) {
        fout << curr;
        if (curr == '\"' && prev != '\\') { // "string" ends
            stringLiteral = false;
        }
        prev = (prev == '\\' && curr == '\\') ? '\0' : curr;
    } else if (comment) {
        if (curr == '/' && prev == '*') { /* comment ends */
            prev = '\0';
            comment = false;
        } else { /* comment text */
            prev = curr;
        }
    } else if (prev == '/') {
        if (curr == '/') { // end of line comment
            fout << '\n';
            prev = '\0';
            while (fin.get() != '\n');
        } else if (curr == '*') { /* comment starts */
            prev = '\0';
            comment = true;
        } else { // normal code
            fout << prev << curr;
            prev = curr;
        }
    } else {
        if (curr != '/') {
            fout << curr;
        }
        charLiteral = (prev != '\\' && curr == '\'');
        stringLiteral = (prev != '\\' && curr == '\"');
        prev = (prev == '\\' && curr == '\\') ? '\0' : curr;
    }
}

}
int main(int argc, char *argv[])
{
    if (argc != 3) {
        cerr << "Usage:\t" << argv[0] << " <input_file> <output_file>\n";
        return 1;
    }

ifstream fin(argv[1]);
ofstream fout(argv[2]);

if (!fin) {
    cerr << "Error:\t\"" << argv[1] << "\" - no such file\n";
    return 1;
}

parse(fin, fout);

fin.close();
fout.close();

return 0;

}</pre>