如何解决在 C++ 程序中嵌入 Perl 脚本
我已将 Perl 解释器嵌入到我的 C++ 程序中,因为我想运行 Perl 脚本。
到目前为止,以下是我的代码 - 它只运行一些虚拟脚本;我想运行 transferScript
脚本,它涉及将两个字符串参数传递给 Perl 脚本。
- 我可以通过解释器运行任意字符串吗?
- 如何将两个字符串参数传递给我的脚本?
谢谢!
#include <EXTERN.h> /* from the Perl distribution */
#include <perl.h> /* from the Perl distribution */
static PerlInterpreter *my_perl; /*** The Perl interpreter ***/
const char* transferScript =
"use Image::ExifTool qw(ImageInfo); \
$srcFile = $ARGV[0]; \
$outFile = $ARGV[1]; \
my $exifTool = new Image::ExifTool; \
my $info = $exifTool->SetNewValuesFromFile($srcFile,'all:all'); \
my $result = $exifTool->WriteInfo($outFile);";
void transferTags(std::string src,std::string dest){
STRLEN n_a;
const char* embedding[] = { "","-e","0" };
my_perl = perl_alloc();
perl_construct( my_perl );
perl_parse(my_perl,NULL,3,(char**)embedding,NULL);
perl_run(my_perl);
/** Treat $a as an integer **/
eval_pv("$a = 3; $a **= 2",TRUE);
printf("a = %d\n",SvIV(get_sv("a",FALSE)));
/** Treat $a as a float **/
eval_pv("$a = 3.14; $a **= 2",TRUE);
printf("a = %f\n",SvNV(get_sv("a",FALSE)));
/** Treat $a as a string **/
eval_pv("$a = 'relreP kcaH rehtonA tsuJ';
$a = reverse($a);",TRUE);
printf("a = %s\n",SvPV(get_sv("a",FALSE),n_a));
perl_destruct(my_perl);
perl_free(my_perl);
}
编辑:这是我的最终代码。
要修复 Debian 上的编译错误,我需要进行一些更改,如下所示:
https://perldoc.perl.org/perlguts#How-multiple-interpreters-and-concurrency-are-supported
#define PERL_NO_GET_CONTEXT
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
class PerlInterp {
public:
PerlInterp() : perlInterp(nullptr) {
dTHX;
std::string script {R"x(
use Image::ExifTool qw(ImageInfo);
use strict;
use warnings;
sub transfer {
my $srcFile = $_[0];
my $outFile = $_[1];
my $exifTool = new Image::ExifTool;
my $info = $exifTool->SetNewValuesFromFile($srcFile,'all:all');
my $result = $exifTool->WriteInfo($outFile);
}
)x"};
constexpr int NUM_ARGS = 3;
const char* embedding[NUM_ARGS] = { "","0" };
PERL_SYS_INIT3(NULL,NULL);
perlInterp = perl_alloc();
perl_construct( perlInterp );
int res = perl_parse(perlInterp,NUM_ARGS,NULL);
assert(!res);
(void)res;
perl_run(perlInterp);
eval_pv(script.c_str(),TRUE);
}
~PerlInterp(){
dTHX;
perl_destruct(perlInterp);
perl_free(perlInterp);
PERL_SYS_TERM();
}
PerlInterpreter *perlInterp;
};
class PerlScriptRunner{
public:
static PerlInterp *instance(void){
static PerlInterp interp;
return &interp;
}
};
void transferExifTags(std::string src,std::string dest){
dTHX;
PerlScriptRunner::instance();
char *args[] = {(char*)src.c_str(),(char*)dest.c_str(),NULL};
call_argv("transfer",G_DISCARD,args);
}
解决方法
以下是使用 @ARGV
和 eval_pv()
的示例:
#include <iostream>
#include <string>
#include <EXTERN.h>
#include <perl.h>
static PerlInterpreter *my_perl;
int main() {
std::string script {R"x(
use feature qw(say);
use strict;
use warnings;
say "Got argument 1 = $ARGV[0]";
say "Got argument 2 = $ARGV[1]";
)x"};
static constexpr int NUM_ARGS = 5;
const char* embedding[NUM_ARGS] = { "","-e","0","Hello","Bye" };
my_perl = perl_alloc();
perl_construct( my_perl );
perl_parse(my_perl,NULL,NUM_ARGS,(char**)embedding,NULL);
perl_run(my_perl);
eval_pv(script.c_str(),TRUE);
perl_destruct(my_perl);
perl_free(my_perl);
return 0;
}
输出:
Got argument 1 = Hello
Got argument 2 = Bye
注意:我使用的是 perl 版本 5.30.0,我编译了这个:
g++ -std=c++17 -o my_test test.cpp `perl -MExtUtils::Embed -e ccopts -e ldopts`
编辑
如果你想用参数多次调用一个子程序,你可以使用call_argv()
。例如:
int main(int argc,char **argv,char **env) {
std::string script {R"x(
use feature qw(say);
use strict;
use warnings;
sub foo {
say "Got argument 1 = $_[0]";
say "Got argument 2 = $_[1]";
}
)x"};
static constexpr int NUM_ARGS = 3;
const char* embedding[NUM_ARGS] = { "","0" };
PERL_SYS_INIT3(&argc,&argv,&env);
my_perl = perl_alloc();
perl_construct( my_perl );
int res1 = perl_parse(my_perl,TRUE);
char *args1[] = {"arg1","arg2",NULL};
call_argv("foo",G_DISCARD,args1);
char *args2[] = {"arg3","arg4",args2);
perl_destruct(my_perl);
perl_free(my_perl);
PERL_SYS_TERM();
return 0;
}
输出:
Got argument 1 = arg1
Got argument 2 = arg2
Got argument 1 = arg3
Got argument 2 = arg4
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。