lua使用ffi调用c程序的函数

朱雀 2021-11-01 08:12 378阅读 0赞

参考： [https://blog.csdn.net/weiwangchao\_/article/details/16880401][https_blog.csdn.net_weiwangchao_article_details_16880401]

[http://luajit.org/ext\_c\_api.html][http_luajit.org_ext_c_api.html]

[https://www.cnblogs.com/darkknightzh/p/5812763.html][https_www.cnblogs.com_darkknightzh_p_5812763.html]

lua 调用 C，需要用到 lua 的 ffi 库，它允许从纯Lua代码调用外部C函数，使用C数据结构，但是C的数据类型并不一定都能转化成lua的数据类型。

\#include <unistd.h>  
\#include <sys/time.h>  
\#include <sys/resource.h>  
\#include <stdio.h>  
\#include <dirent.h>

struct rlimit rlmt;

char\* get\_size()  
\{   
 　　if (getrlimit(RLIMIT\_CORE, &rlmt) == -1) \{   
 　　return -1;  
 　　\}  
 　　return (char\*)rlmt.rlim\_cur;

\};

char\* set\_size(double CORE\_SIZE)  
\{   
 　　rlmt.rlim\_cur = (rlim\_t)CORE\_SIZE;  
 　　rlmt.rlim\_max = (rlim\_t)CORE\_SIZE;

if (setrlimit(RLIMIT\_CORE, &rlmt) == -1) \{   
 　　return -1;  
 　　\}

return (char\*)rlmt.rlim\_cur;

\};

int cd\_chdir(const char \*dirname)  
\{   
 　　int a=chdir(dirname);  
 　　return a;

\};

【g++ 编译一下，变成 \*.so 文件 】

下面为 Makefile  文件， 在目录下 make  能直接生成 \*.so  文件 ，修改里面的  \*.so   \*.o  文件

\#\# Linux/BSD

LDFLAGS += -shared

CFLAGS ?= -g -O -Wall  
override CFLAGS += -fpic

\#CC = gcc  
RM = rm -f

COPY = cp

all: my\_corefile.so

my\_corefile.o: my\_corefile.c

my\_corefile.so: my\_corefile.o  
 $(CC) $(LDFLAGS) $^ -o $@

clean:  
 $(RM) \*.so \*.o

lua  文件

local ffi = require 'ffi'  
\--local ffi\_string = ffi.string  
\--local ffi\_new = ffi.new  
\--local C = ffi.C

ffi.cdef\[\[  
 　　int get\_size();  
 　　int set\_size(long CORE\_SIZE);  
 　　int cd\_chdir(const char \*dirname);  
\]\]

set\_get\_core = ffi.load('/home/chentao/c\_test/c\_lua/qq/mycorefile/my\_corefile.so')--直接导入绝对路径

local a = set\_get\_core.get\_size()  
print(a)

local b = set\_get\_core.set\_size(524280)  
print(b)

print("hass set")  
local a = set\_get\_core.get\_size()  
print(a)

print(os.getenv("PWD"))

print(" cd ",set\_get\_core.cd\_chdir("/home"))

导入路径为 绝对路径

转载于:https://www.cnblogs.com/chenpython123/p/11042042.html

[https_blog.csdn.net_weiwangchao_article_details_16880401]: https://blog.csdn.net/weiwangchao_/article/details/16880401
[http_luajit.org_ext_c_api.html]: http://luajit.org/ext_c_api.html
[https_www.cnblogs.com_darkknightzh_p_5812763.html]: https://www.cnblogs.com/darkknightzh/p/5812763.html