Стандартные операции с файлами Опции

[Andrew Selivanov]

Вообщем то не открою Америки...
Удалить файлик стандартно можно так: std::remove("path");
Переименовать файлик: std::rename("from","to");

А вот копирование можно сделать ну не менее чем 30-ю разными способами И самый быстрый способ будет Си-шный. Если кому интересно скину.

[Andrew Selivanov]

скинь коль уж начал

Дык не вопрос, совершенно не вопрос...
По ссылке можно найти и результаты тестирования в том числе, в этом сообщении сами исходники
http://groups.google.com/group/perfo/brows...4466f69541c2e63

===================== 4. Methods of copying : BEGIN ===================== 

FILE*         ifp;  // input  file pointer 
FILE*         ofp;  // output file pointer 

int           ifd;  // input  file descriptor; UNIX 
int           ofd;  // output file descriptor; UNIX 

ifstream      ifs;  // input  file stream 
ofstream      ofs;  // output file stream 

// ----- 
// Note. Files are tested in both modes text and binary 
// ----- 

char          ch; 
int           ich; 
const int     newline_int_symbol (int ('\n')); 

size_t        nread; 
streamsize    len; 
size_t        no_of_file_bytes;  // File size (number of bytes) 
size_t        no_of_file_lines;  // Number of file lines 
// ----- 
// Note. 'no_of_file_bytes' doesn't contain number of '\r' in '\r\n' 
// ----- 

char          const_buf [4096]; 
char*         max_buf = new char [no_of_file_bytes + no_of_file_lines + 1]; 

string        line; 
string        str; 
ostringstream oss; 

struct char_identity { char operator()(char ch) const { return ch; } }; 

    ### C-01: C-Functions getc() and putc() 
    ------------------------------------------------ 
    while ((ich = getc(ifp)) != EOF) putc(ich, ofp); 
    ------------------------------------------------ 

    ### C-02: C-Functions fgetc() and fputc() 
    ------------------------------------------------ 
    while ((ich = fgetc(ifp)) != EOF) fputc(ich, ofp); 
    ------------------------------------------------ 

    ### C-03: C-Functions fread() and fwrite() - with const size buffer 
    ------------------------------------------------ 
    while ((nread = fread(const_buf, sizeof(char), sizeof(const_buf), ifp)) > 0) 
    { 
      fwrite(const_buf, sizeof(char), nread, ofp); 
    } 
    ------------------------------------------------ 

    ### C-04: C-Functions fread() and fwrite() - with max size buffer 
    ------------------------------------------------ 
    while ((nread = fread(max_buf, sizeof(char), sizeof(max_buf), ifp)) > 0) 
    { 
      fwrite(max_buf, sizeof(char), nread, ofp); 
    } 
    ------------------------------------------------ 

    ### Unix-C-05: UNIX system call mmap() 
    ------------------------------------------------ 
    size_t actual_file_size = no_of_file_bytes + ((text-mode) ? no_of_file_lines : 0) 
    char* ptr = (char*)mmap(0, actual_file_size, PROT_READ, MAP_SHARED, ifd, 0); 
    write(ofd, ptr, actual_file_size); 
    munmap(ptr, actual_file_size); 
    ------------------------------------------------ 

    ### CPP-01: istream::operator>> and ostream::operator<< 
    ------------------------------------------------ 
    ifs.unsetf(ios::skipws); 
    while (ifs >> ch) ofs << ch; 
    ------------------------------------------------ 

    ### CPP-02: streambuf::sbumpc() and streambuf::sputc() 
    ------------------------------------------------ 
    while ((ch = ifs.rdbuf()->sbumpc()) != EOF) ofs.rdbuf()->sputc(ch); 
    ------------------------------------------------ 

    ### CPP-03: streambuf::sbumpc() and ostream::operator<< 
    ------------------------------------------------ 
    ch = ifs.rdbuf()->sbumpc(); 
    ofs << ch; 
    while (ch != EOF) 
    { 
      ofs << ifs.rdbuf(); 
      ch = ifs.rdbuf()->sbumpc(); 
    } 
    ------------------------------------------------ 

    ### CPP-04: ifstream::rdbuf() and ostream::operator<< 
    ------------------------------------------------ 
    ofs << ifs.rdbuf(); 
    ------------------------------------------------ 

    ### CPP-05: istream::read() and ostream::write() - with const size buffer 
    ------------------------------------------------ 
    while (!ifs.eof()) 
    { 
      ifs.read (const_buf, sizeof(const_buf)); 
      ofs.write (const_buf, ifs.gcount()); 
    } 
    ------------------------------------------------ 

    ### CPP-06: istream::read() and ostream::write(), std::ostringstream, ostream::operator<< - with const buffer 
    ------------------------------------------------ 
    while (!ifs.eof()) 
    { 
      ifs.read (const_buf, sizeof(const_buf)); 
      oss.write (const_buf, ifs.gcount()); 
    } 
    ofs << oss.str(); 
    ------------------------------------------------ 

    ### CPP-07: istream::readsome() and ostream::write() - with const size buffer 
    ------------------------------------------------ 
    do 
    { 
      len = ifs.readsome (const_buf, sizeof(const_buf)); 
      ofs.write (const_buf, len); 
    } while (len); 
    ------------------------------------------------ 

    ### CPP-08: istream::read() and ostream::write() - with max size buffer 
    ------------------------------------------------ 
    while (!ifs.eof()) 
    { 
      ifs.read (max_buf, no_of_file_bytes + no_of_file_lines); 
      ofs.write (max_buf, ifs.gcount()); 
    } 
    ------------------------------------------------ 

    ### CPP-09: std::getline, std::ostringstream, ostream::operator<< 
    ------------------------------------------------ 
    while (getline (ifs, line)) oss << line << '\n'; 
    string tmp(oss.str()); 
    if (!tmp.empty()) 
    { 
      ifs.rdbuf()->sungetc (); 
      if (ifs.rdbuf()->sgetc() != '\n') tmp.erase(tmp.size() - 1); 
    } 
    ofs << tmp; 
    ------------------------------------------------ 

    ### CPP-10: std::getline, std::string, ostream::operator<< 
    ------------------------------------------------ 
    while (getline (ifs, line)) 
    { 
      str +=line; 
      str +='\n'; 
    } 
    if (!str.empty()) 
    { 
      ifs.rdbuf()->sungetc (); 
      if (ifs.rdbuf()->sgetc() != '\n') str.erase(str.size() - 1); 
    } 
    ofs << str; 
    ------------------------------------------------ 

    ### CPP-11: istream::getline, std::ostringstream, ostream::operator<< 
    ------------------------------------------------ 
    while (ifs.getline (const_buf, sizeof(const_buf)).gcount()) 
    { 
      oss << const_buf; 
      if (ifs.fail()) ifs.clear (~(ios_base::failbit | ~ifs.rdstate ())); 
      else            oss << '\n'; 
    } 
    string tmp(oss.str()); 
    if (!tmp.empty()) 
    { 
      ifs.rdbuf()->sungetc (); 
      if (ifs.rdbuf()->sgetc() != '\n') tmp.erase(tmp.size() - 1); 
    } 
    ofs << tmp; 
    ------------------------------------------------ 

    ### CPP-12: istream::get(char) and ostream::put 
    ------------------------------------------------ 
    while (ifs.get(ch)) ofs.put(ch); 
    ------------------------------------------------ 

    ### CPP-13: istream::get(char) 
    ------------------------------------------------ 
    for (unsigned long i = 0; ifs.get (ch); i++) str[i] = ch; 
    str.erase (i); 
    ofs << str; 
    ------------------------------------------------ 

    ### CPP-14: istream::get(char*, streamsize), ostream::operator<< - with const size buffer 
    ------------------------------------------------ 
    while (ifs.get (const_buf, sizeof(const_buf))) 
    { 
      ofs << const_buf; 
      if (ifs.peek() == newline_int_symbol) ofs << char(ifs.get()); 
    } 
    ------------------------------------------------ 

    ### CPP-15: istream::get(streambuf&)  and std::streambuf, ostream::operator<< 
    ------------------------------------------------ 
    while (ifs.get (*ofs.rdbuf())) 
    { 
      if (ifs.peek() == newline_int_symbol) ofs << char(ifs.get()); 
    } 
    ------------------------------------------------ 

    ### CPP-16: std::istream_iterator, std::ostream_iterator and std::copy 
    ------------------------------------------------ 
    ifs >> noskipws; 
    istream_iterator<char> in(ifs), eos; 
    ostream_iterator<char> out(ofs); 
    copy (in, eos, out); 
    ------------------------------------------------ 

    ### CPP-17: std::istream_iterator, std::string 
    ------------------------------------------------ 
    ifs >> noskipws; 
    istream_iterator<char> in(ifs), eos; 
    ofs << string(in, eos); 
    ------------------------------------------------ 

    ### CPP-18: std::istreambuf_iterator, std::ostreambuf_iterator and std::copy 
    ------------------------------------------------ 
    ifs >> noskipws; 
    istreambuf_iterator<char> in(ifs), eos; 
    ostreambuf_iterator<char> out(ofs); 
    copy (in, eos, out); 
    ------------------------------------------------ 

    ### CPP-19: std::istreambuf_iterator, std::ostreambuf_iterator and std::transform 
    ------------------------------------------------ 
    ifs >> noskipws; 
    istreambuf_iterator<char> in(ifs), eos; 
    ostreambuf_iterator<char> out(ofs); 
    transform(in, eos, out, char_identity()); 
    ------------------------------------------------ 

    ### CPP-20: std::istreambuf_iterator and std::string 
    ------------------------------------------------ 
    ifs >> noskipws; 
    istreambuf_iterator<char> in(ifs), eos; 
    ofs << string(in, eos); 
    ------------------------------------------------ 

    ### CPP-21: std::vector and std::copy 
    ------------------------------------------------ 
    vector<char> v (no_of_file_bytes); 
    ifs.read(&v[0], no_of_file_bytes); 
    ostream_iterator<char> out(ofs); 
    copy (&v[0], &v[v.size()], out); 
    ------------------------------------------------ 

    ### CPP-22: std::vector and push_back() 
    ------------------------------------------------ 
    vector<char> v; 
    v.reserve(no_of_file_bytes); 
    while (ifs.get(ch)) v.push_back(ch); 
    ofs << (v.empty() ? string() : string (v.begin(), v.end())); 
    ------------------------------------------------ 

    ### CPP-23: std::vector and istream::read() 
    ------------------------------------------------ 
    vector<char> v (no_of_file_bytes); 
    ifs.read(&v[0], no_of_file_bytes); 
    ofs << (v.empty() ? string() : string (v.begin(), v.end())); 
    ------------------------------------------------ 

    ### CPP-24: std::string and istream::read() 
    ------------------------------------------------ 
    string tmp (no_of_file_bytes, '0'); 
    ifs.read(&tmp[0], no_of_file_bytes); 
    ofs << tmp; 
    ------------------------------------------------ 

===================== 4. Methods of copying : END =======================