Miscellaneous skills for C, C++11/14/17/20, Python2/3, ECMAScript5/6 and Shell Script.
Given a byte count, converts it to human-readable format and returns a string consisting of a value and a units indicator.
Depending on the size of the value, the units part is bytes, KB (kibibytes), MB (mebibytes), GB (gibibytes), TB (tebibytes), or PB (pebibytes)...
Function Prototype
template<typename CharT, typename ByteT> CharT const* format_bytes(std::basic_string<CharT>& repr // (1) , ByteT const bytes , std::size_t const decimal=2u , std::size_t const reduced_unit=1024u); template<typename CharT, typename ByteT, typename IndicatorT , typename = typename std::enable_if<!std::is_integral<IndicatorT>::value>::type> CharT const* format_bytes(std::basic_string<CharT>& repr // (2) , ByteT const bytes , IndicatorT&& indicator , std::size_t const decimal=2u , std::size_t const reduced_unit=1024u); template<typename CharT, typename ByteT, typename InputIt> CharT const* format_bytes(std::basic_string<CharT>& repr // (3) , ByteT const bytes , InputIt first, InputIt last , std::size_t const decimal=2u , std::size_t const reduced_unit=1024u); template<typename CharT, typename ByteT , typename InputIt, typename IndicatorT> CharT const* format_bytes(std::basic_string<CharT>& repr // (4) , ByteT const bytes , InputIt first, InputIt last , IndicatorT&& indicator , std::size_t const decimal=2u , std::size_t const reduced_unit=1024u);Usage
using namespace ymh::misc; std::string s; std::cout << format_bytes(s, 18446640) << std::endl;equal to:
std::wstring wcs; // unicode auto indicators = { "Bytes", "KB", "MB", "GB" }; format_bytes(s, 18446640 , std::begin(indicators), std::end(indicators) , "MB", 2u, 1024u);Output
17.60 MBSave std::error_code, boost.system, GetLastError(), user custom error code and error message to class [w]error_t.
Query error information by dump() or dump_backtrace() from class [w]error_t, it can query error domain, value, message by the numbers of [w]error_t.
Function Prototype
(1) User Custom Error
SET_ERROR_CUSTOM[W](error_t&, domain, value, format_string, ...); SET_ERROR_MESSAGE[W](error_t&, value, format_string, ...); SET_ERROR_STRING[W](error_t&, format_string, ...);(2) std::error_code or boost.system
SET_ERROR_CODE[W](error_t&, error_code); MAKE_ERROR_CODE[W](error_t&, errc_t);(3) System Error
SET_SYSTEM_ERROR[W](error_t&, ::GetLastError()); // errno(4) Catch Exception
ERROR_TRY[W] { // throw exception } ERROR_CATCH[W](error_t&)(5) Print Error Message to Stream
void error_t::dump(std::basic_ostream<charT>&); void error_t::dump_backtrace(std::basic_ostream<charT>&);Usage
using namespace ymh; error_t err; SET_ERROR_STRING(err, "Open file %s failed", "error.log"); if (err) // return true if error occur { SET_SYSTEM_ERROR(err, ::GetLastError()); }Output
File "xxx.cpp", line ?, in <function>: Open file error.log failed File "xxx.cpp", line ?, in <function>: SuccessUnicode and ANSI (byte string) conversion is supported by class codec.
Convert wide char to multi bytes by encode<codepage::cp_xxx, bom::nobomb> and reverse it by decode<codepage::cp_xxx, bom::nobomb>. It can convert one multi bytes to another multi bytes by convert<...>.
Others, it will try convert to local codepage if you use file_text to read file's contents. You can save multi bytes to file by save_file_text<...>.
Attention : may throw std::system_error exception if failed.
Function Prototype
(1) Multi Bytes to Wide Char
std::wstring wtext = decode<codepage::cp_utf8>(u8"utf-8 string"); wtext = UTF8ToUnicode<bom::nobomb>(u8"utf-8 string");"(2) Wide Char to Multi Bytes
std::string text = encode<codepage::cp_utf8>(L"wide string"); text = UnicodeToUTF8<bom::bomb>(L"wide string");(3) Convert between Multi Bytes
std::string ntext = convert<codepage::cp_utf8>("ansi string");(4) Read/Save File Text
std::wstring wtext = read_file_text(L"demo.txt"); save_file_text<codepage::cp_utf8, bom::bomb>("demo.txt", "bingo");Usage
using namespace ymh; try { auto text = file_text("demo.txt"); auto wtext = decode(text); } catch (std::system_error const& e) { }Measure compression ratio. zlib, gzip, bz2, lzma is supported.
Usage
usage: mcr.py [-h] [--verbose] [--chunk-size {4,8,16,32,64,128,256,512}] [--name {gzip,all,zlib,bz2}] [--level {-2,-1,0,1,2,3,4,5,6,7,8,9}] file Measure compression ratio. positional arguments: file file or directory optional arguments: -h, --help show this help message and exit --verbose print progress status (default: None) --chunk-size {4,8,16,32,64,128,256,512} data chunk's size (metric: KB) (default: 16) --name {gzip,all,zlib,bz2} compression algorithm's name (default: all) --level {-2,-1,0,1,2,3,4,5,6,7,8,9} controlling the level of compression, all = -2, default = -1 (default: -2)Example
$ python3 mcr.py --level=-1 /dev/vda File: /dev/vda, Length: 40.0 GB, Chunk Size: 16.0 KB NAME LVL OUTSIZE EXPIRED %SAV IN/ps OUT/ps RATIO %PROG REMAIN bz2 9 6.61 GB 1.1 h 83.48 10.33 MBps 1.71 MBps 6.05 100.0 0.0 s zlib -1 8.74 GB 14.93 m 78.15 45.72 MBps 9.99 MBps 4.58 100.0 0.0 s gzip 9 8.75 GB 50.93 m 78.13 13.4 MBps 2.93 MBps 4.57 100.0 0.0 s lzma 0 4.43 GB 3.03 h 88.93 3.75 MBps 425.55 KBps 9.03 100.0 0.0 s