removing comments of c,c++, java styles

rohit83.ken 0 Tallied Votes 111 Views Share

hello frnds this is a snippet that removes comments of c, c++ , java files

// 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;
}