shell c 混合编程 system 输出数据到变量【转】

爱被打了一巴掌 2021-11-02 03:16 282阅读 0赞

# 转自:[http://www.cnblogs.com/wangkangluo1/archive/2012/02/08/2342597.html][http_www.cnblogs.com_wangkangluo1_archive_2012_02_08_2342597.html] #

# [shell c 混合编程 system 输出数据到变量][http_www.cnblogs.com_wangkangluo1_archive_2012_02_08_2342597.html] #

shell c 混合编程 system 输出数据到变量

方法一： （popen）

[![复制代码][copycode.gif]][copycode.gif 1]

#include <stdio.h>
    #include <stdlib.h>
    
    
    int main( int argc, char *argv[] )
    {
          
    
      FILE *fp;
    int status;
    char path[1035];
    
    /* Open the command for reading. */
      fp = popen("/bin/ls /etc/", "r");
    if (fp == NULL) {
          
        printf("Failed to run command\n" );
        exit;
      }
    
    /* Read the output a line at a time - output it. */
    while (fgets(path, sizeof(path)-1, fp) != NULL) {
          
        printf("%s", path);
      }
    
    /* close */
      pclose(fp);
    
    return 0;
    }

[![复制代码][copycode.gif]][copycode.gif 1]

方法二：

[![复制代码][copycode.gif]][copycode.gif 1]

#include <stdio.h>
    #include <stdlib.h>
    
    
    
    static int my_system(const char* pCmd, char* pResult, int size)
    {
          
    int fd[2];
    int pid;
    int count;
    int left;
    char* p = 0;
    int maxlen = size - 1;
        memset(pResult, 0, size);
    if(pipe(fd))
            {
          
                printf("pipe error\n");
    return -1;
            }
    if((pid = fork()) == 0)
            {
          // chile process
                int fd2[2];
    if(pipe(fd2))
                    {
          
                        printf("pipe2 error\n");
    return -1;
                    }
                close(1);
                dup2(fd2[1],1);
                close(fd[0]);
                close(fd2[1]);
                system(pCmd);
                read(fd2[0], pResult, maxlen);
                pResult[strlen(pResult)-1] = 0;
                write(fd[1], pResult, strlen(pResult));
                close(fd2[0]);
                exit(0);
            }
    // parent process
        close(fd[1]);
        p = pResult;
        left = maxlen;
    while((count = read(fd[0], p, left))) {
          
            p = count;
            left -= count;
    if(left == 0)
    break;
        }
        close(fd[0]);
    return 0;
    }
    int main(void)
    {
          
    char result[1025];
        my_system("LC_ALL=C ifconfig", result, 1025);
        printf("the result is\n\n%s\n", result);
    return 0;
    }

[![复制代码][copycode.gif]][copycode.gif 1]

完

转载于:https://www.cnblogs.com/Leo-Forest/archive/2012/06/24/2560464.html

[http_www.cnblogs.com_wangkangluo1_archive_2012_02_08_2342597.html]: http://www.cnblogs.com/wangkangluo1/archive/2012/02/08/2342597.html
[copycode.gif]: https://common.cnblogs.com/images/copycode.gif
[copycode.gif 1]: /images/20211102/f6dd2d797b0449eb9f10b6d10d5b372b.png