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 formatand 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>CharTconst*format_bytes(std::basic_string<CharT>& repr// (1) , ByteTconst bytes , std::size_tconst decimal=2u , std::size_tconst reduced_unit=1024u);template<typename CharT,typename ByteT,typename IndicatorT ,typename =typename std::enable_if<!std::is_integral<IndicatorT>::value>::type>CharTconst*format_bytes(std::basic_string<CharT>& repr// (2) , ByteTconst bytes , IndicatorT&& indicator , std::size_tconst decimal=2u , std::size_tconst reduced_unit=1024u);template<typename CharT,typename ByteT,typename InputIt>CharTconst*format_bytes(std::basic_string<CharT>& repr// (3) , ByteTconst bytes , InputIt first, InputIt last , std::size_tconst decimal=2u , std::size_tconst reduced_unit=1024u);template<typename CharT,typename ByteT ,typename InputIt,typename IndicatorT>CharTconst*format_bytes(std::basic_string<CharT>& repr// (4) , ByteTconst bytes , InputIt first, InputIt last , IndicatorT&& indicator , std::size_tconst decimal=2u , std::size_tconst reduced_unit=1024u);
Usage
usingnamespaceymh::misc;std::string s;std::cout << format_bytes(s,18446640) << std::endl;
equal to:
std::wstring wcs;// unicodeauto indicators = {"Bytes","KB","MB","GB" };format_bytes(s,18446640 , std::begin(indicators), std::end(indicators) , "MB", 2u, 1024u);Output
Save std::error_code, boost.system, GetLastError(), user custom error codeand 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
voiderror_t::dump(std::basic_ostream<charT>&);voiderror_t::dump_backtrace(std::basic_ostream<charT>&);
Usage
usingnamespaceymh;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 failedFile"xxx.cpp", line?,in<function>: Success
Unicode and ANSI (byte string) conversion is supported by classcodec.
Convert wide char to multi bytes byencode<codepage::cp_xxx, bom::nobomb>and reverse it bydecode<codepage::cp_xxx, bom::nobomb>. It can convert onemulti bytes to another multi bytes byconvert<...>.
Others, it will try convert to local codepage if you usefile_text to readfile's contents. You can save multi bytes to file bysave_file_text<...>.
Attention : may throwstd::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
usingnamespaceymh;try{auto text =file_text("demo.txt");auto wtext =decode(text);}catch (std::system_errorconst& 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}] fileMeasure compression ratio.positional arguments: file file or directoryoptional arguments: -h, --help show thishelp message andexit --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/vdaFile: /dev/vda, Length: 40.0 GB, Chunk Size: 16.0 KBNAME 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 szlib -1 8.74 GB 14.93 m 78.15 45.72 MBps 9.99 MBps 4.58 100.0 0.0 sgzip 9 8.75 GB 50.93 m 78.13 13.4 MBps 2.93 MBps 4.57 100.0 0.0 slzma 0 4.43 GB 3.03 h 88.93 3.75 MBps 425.55 KBps 9.03 100.0 0.0 s