如何在Mac上用Ruby封装C/C++接口
最近在codecademy上学习了下Ruby，顺便分享下如何在Mac上用Ruby封装Dynamsoft C/C++ barcode API 。
参考原文：How to Make Ruby Barcode Reader with C++ Barcode SDK on Mac OS X
作者：Xiao Ling
翻译：yushulx
下载SDK
http://www.dynamsoft.com/Downloads/Dynamic-Barcode-Reader-Download.aspx
创建Ruby Barcode工程
创建extconf.rb：
require 'mkmf' extension_name = 'dynamsoftbarcode' dir_config(extension_name) create_makefile(extension_name)
自动生成Makefile：
ruby extconf .rb
打开Makefile，修改配置。
添加头文件路径
dbrdir = /Applications/Dynamsoft/Barcode\ Reader\ 3.0\ Trial/Include INCFLAGS = -I. -I$(arch_hdrdir) -I$(hdrdir)/ruby/backward -I$(hdrdir) -I$(srcdir) -I$(dbrdir)
添加库路径
LIBS = $(LIBRUBYARG_SHARED) -lpthread -ldl -lobjc -lDynamsoftBarcodeReader
打开dynamsoftbarcode.c，添加入口和方法：
VALUE BarcodeReader = Qnil;
void Init_dynamsoftbarcode();
VALUE method_decodeFile(VALUE self, VALUE path);
void Init_dynamsoftbarcode() {
BarcodeReader = rb_define_module("BarcodeReader");
rb_define_method(BarcodeReader, "decodeFile", method_decodeFile, 1);
}
VALUE method_decodeFile(VALUE self, VALUE path) {
char *pszPath = StringValueCStr(path);
VALUE ary = decode(pszPath);
return ary;
}
使用Dynamsoft Barcode SDK提供的代码：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <If_DBR.h>
#define strcmpi(dst, src) strcasecmp(dst, src)
__int64 GetFormat(const char * pstr)
{
__int64 llFormat = 0;
const char * pszFormat = pstr;
if (strcasestr(pszFormat, "code_39") != NULL)
llFormat |= CODE_39;
if (strcasestr(pszFormat, "code_128") != NULL)
llFormat |= CODE_128;
if (strcasestr(pszFormat, "code_93") != NULL)
llFormat |= CODE_93;
if (strcasestr(pszFormat, "codabar") != NULL)
llFormat |= CODABAR;
if (strcasestr(pszFormat, "itf") != NULL)
llFormat |= ITF;
if (strcasestr(pszFormat, "upc_a") != NULL)
llFormat |= UPC_A;
if (strcasestr(pszFormat, "upc_e") != NULL)
llFormat |= UPC_E;
if (strcasestr(pszFormat, "ean_13") != NULL)
llFormat |= EAN_13;
if (strcasestr(pszFormat, "ean_8") != NULL)
llFormat |= EAN_8;
if (strcasestr(pszFormat, "industrial_25") != NULL)
llFormat |= INDUSTRIAL_25;
if (strcasestr(pszFormat, "oned") != NULL)
llFormat = OneD;
if (strcasestr(pszFormat, "qr_code") != NULL)
llFormat |= QR_CODE;
return llFormat;
}
const char * GetFormatStr(__int64 format)
{
if (format == CODE_39)
return "CODE_39";
if (format == CODE_128)
return "CODE_128";
if (format == CODE_93)
return "CODE_93";
if (format == CODABAR)
return "CODABAR";
if (format == ITF)
return "ITF";
if (format == UPC_A)
return "UPC_A";
if (format == UPC_E)
return "UPC_E";
if (format == EAN_13)
return "EAN_13";
if (format == EAN_8)
return "EAN_8";
if (format == INDUSTRIAL_25)
return "INDUSTRIAL_25";
if (format == QR_CODE)
return "QR_CODE";
return "UNKNOWN";
}
int decode(const char *pszImageFile)
{
__int64 llFormat = (OneD |QR_CODE);
int iMaxCount = 0x7FFFFFFF;
int iIndex = 0;
ReaderOptions ro = {0};
pBarcodeResultArray paryResult = NULL;
int iRet = -1;
char * pszTemp = NULL;
char * pszTemp1 = NULL;
struct timeval begin, end;
if (NULL == pszImageFile)
{
printf("The syntax of the command is incorrect.\n");
return 1;
}
// Set license
DBR_InitLicense("B8DF4560D0953299D5454C71A38D1FEB");
// Read barcode
gettimeofday(&begin, NULL);
ro.llBarcodeFormat = llFormat;
ro.iMaxBarcodesNumPerPage = iMaxCount;
iRet = DBR_DecodeFile(pszImageFile, &ro, &paryResult);
gettimeofday(&end, NULL);
// Output barcode result
pszTemp = (char*)malloc(4096);
if (iRet != DBR_OK)
{
sprintf(pszTemp, "Failed to read barcode: %s\r\n", DBR_GetErrorString(iRet));
printf("%s", pszTemp);
free(pszTemp);
return 1;
}
if (paryResult->iBarcodeCount == 0)
{
sprintf(pszTemp, "No barcode found. Total time spent: %.3f seconds.\r\n",
((float)((end.tv_sec * 1000 * 1000 + end.tv_usec) - (begin.tv_sec * 1000 * 1000 + begin.tv_usec))/(1000 * 1000)));
printf("%s", pszTemp);
DBR_FreeBarcodeResults(&paryResult);
return 0;
}
sprintf(pszTemp, "Total barcode(s) found: %d. Total time spent: %.3f seconds\r\n\r\n", paryResult->iBarcodeCount,
((float)((end.tv_sec * 1000 * 1000 + end.tv_usec) - (begin.tv_sec * 1000 * 1000 + begin.tv_usec))/(1000 * 1000)));
printf("%s", pszTemp);
for (iIndex = 0; iIndex < paryResult->iBarcodeCount; iIndex++)
{
sprintf(pszTemp, "Barcode %d:\r\n", iIndex + 1);
// printf("%s", pszTemp);
sprintf(pszTemp, "%s Page: %d\r\n", pszTemp, paryResult->ppBarcodes[iIndex]->iPageNum);
// printf("%s", pszTemp);
sprintf(pszTemp, "%s Type: %s\r\n", pszTemp, GetFormatStr(paryResult->ppBarcodes[iIndex]->llFormat));
// printf("%s", pszTemp);
pszTemp1 = (char*)malloc(paryResult->ppBarcodes[iIndex]->iBarcodeDataLength + 1);
memset(pszTemp1, 0, paryResult->ppBarcodes[iIndex]->iBarcodeDataLength + 1);
memcpy(pszTemp1, paryResult->ppBarcodes[iIndex]->pBarcodeData, paryResult->ppBarcodes[iIndex]->iBarcodeDataLength);
sprintf(pszTemp, "%s Value: %s\r\n", pszTemp, pszTemp1);
// printf("%s", pszTemp);
free(pszTemp1);
}
free(pszTemp);
DBR_FreeBarcodeResults(&paryResult);
return iRet;
}
把C String转换成 VALUE（VALUE表示Ruby对象）。
VALUE ary = rb_ary_new(); rb_ary_push(ary, rb_str_new_cstr(pszTemp));
创建Ruby脚本barcode_reader.rb调用接口：
require 'dynamsoftbarcode'
include BarcodeReader
if ARGV.length == 0
puts "Please add a barcode file path!"
else
$filePath = ARGV[0]
$results = decodeFile($filePath)
$results.each do |i|
puts "#{i}"
end
puts "Game Over!"
end
执行make。如果看到下面的警告：
ld: warning: directory not found for option '-L/usr/local/lib'
打开Makefile ，把
ldflags = -L. -L/usr/local/lib
改成
ldflags = -L. -L/usr/lib.
再make一次就好了：
linking shared-object dynamsoftbarcode.bundle
运行sudo make install安装。
执行脚本测试：
ruby barcode_reader.rb barcode_file
截图：
参考
http://docs.ruby-lang.org/en/2.1.0/README_EXT.html
https://silverhammermba.github.io/emberb/c/
源码
https://github.com/dynamsoftsamples/ruby-barcode-reader