Question

char *c = strtok(a, "|"); // array for the different tokens in the command
char *d = strtok(NULL,"|");
pid_t cpid;
pipe(pfd);
cpid = fork();
if(cpid == 0){
/* child */
    cout << "you are in child";
    dup2(pfd[0], 0);
    close(pfd[0]);
    close(pfd[1]);  /* the child does not need this end of the pipe */
    cout << c;
    execString(c);
    //perror(cmd2[0]);
    cout << "error";
} else{
    cpid = fork();
    if(cpid == 0){
 /* parent */
    cout <<"you are in parent";
    cout << d;
    dup2(pfd[1], 1);
    close(pfd[0]);
    close(pfd[1]);  /* the parent does not need this end of the pipe */
    execString(d);
    //perror(cmd1[0]);
    cout << "error";
} else{
    int status;
    close(pfd[0]);
    close(pfd[1]);  
    waitpid(cpid, &status, 0);
    perror("fork");
    exit(1);

}


}

我通过输入ls -l |来测试这段代码wc -l，execstring方法将我的char数组分解为标记并执行它们。我知道这很糟糕，我很久没有做过任何C / C ++了。这很奇怪，因为子进程可以成功执行命令，我仍然可以看到ls -l的输出。我得到的错误来自wc -l，控制台打印回来＆＃34; wc：无效选项 - ＆＃39;＆＃39;。尝试使用wc - help获取更多信息。有任何想法吗？

void execString(char *b){
char *tokens = strtok(b, " ");
pid_t child_pid;
int child_status;
child_pid = fork();
vector<char *> commandVector;

while(tokens != NULL){

commandVector.push_back(tokens);
tokens = strtok(NULL," ");
}
cout << tokens << endl;
//cout<< "execString"<<endl;
commandVector.push_back(NULL);
char **args = &commandVector[0];
int status = execvp(args[0], args);



}

Answer 1

我修好了，管道索引被颠倒了。我将exec命令更改为常量字符串以测试它是否有效。它工作正常。要调整我的execString。

管道方法在父进程上保持失败

1 个答案: