C ++ forksubprocess，请求subprocess列表，在Linux中杀死进程

我试图创build一个subprocess，发送subprocess命令“LISTALL”。 subprocess然后应该向系统发出命令ps并将该列表返回给父进程。父进程应该select一个进程并杀死它。这是我迄今为止，但我只是得到它运行麻烦。

#include <stdio.h> #include <unistd.h> #include <cstring> #include <stdlib.h> #include <iostream> #include <sys/wait.h> char* getlistOfProcesses(const char* cmd) { FILE* pipe = popen(cmd, "r"); if (!pipe) return (char*)"ERROR"; char buffer[128]; char *result = new char[1024]; while(!feof(pipe)) { if(fgets(buffer, 128, pipe) != NULL) strcat(result, buffer); } pclose(pipe); return result; } int spawnGEdit() { pid_t gPid = fork(); if(gPid == 0) { execl("gedit", "gedit", NULL); exit(-1); } else { } return 0; } int main(int argc, char **argv) { int P2C[2]; int C2P[2]; pipe(P2C); pipe(C2P); pid_t cPid = fork(); char cmd[50]; char* listOfProcesses = new char[1024]; spawnGEdit(); if (cPid == 0) { close(P2C[1]); close(C2P[0]); read(P2C[0], cmd, 10); if(strcmp(cmd,"LISTALL") == 0) { write(C2P[1], getlistOfProcesses("ps"), 1024); close(P2C[0]); close(C2P[1]); } } else if (cPid > 0) { close(C2P[1]); close(P2C[0]); write(P2C[1], "LISTALL", 10); wait(NULL); read(C2P[0], listOfProcesses,1024); printf("%s",listOfProcesses); //TODO //get user input of a PID //kill the PID close(C2P[0]); close(P2C[1]); } else { // fork failed printf("Forking failed!\n"); exit(1); } return 0; }

这些是我在尝试编译时遇到的错误：

 /tmp/cciTPIOZ.o: In function `getlistOfProcesses(char const*)': test.cpp:(.text+0x53): undefined reference to `operator new[](unsigned long)' /tmp/cciTPIOZ.o: In function `main': test.cpp:(.text+0x166): undefined reference to `operator new[](unsigned long)' /tmp/cciTPIOZ.o: In function `__static_initialization_and_destruction_0(int, int)': test.cpp:(.text+0x2c0): undefined reference to `std::ios_base::Init::Init()' test.cpp:(.text+0x2cf): undefined reference to `std::ios_base::Init::~Init()' collect2: error: ld returned 1 exit status

我正在编译：

 cc test.cpp -o test

编译错误行号：9,53,64可以通过使用这些解决：

第9行： FILE* pipe = popen(cmd.data(), "r");

第53行： write(C2P[1], getlistOfProcesses("ps").data(), 1024);

第64行： printf("%s",listOfProcesses.data());

原因：这些popen，write，printf需要char *作为它们的参数，但是你传递它们的std :: string。你必须使用std :: string.data（）函数，因为它返回指向由std::string对象表示的字符数组的指针。

对于你在第63行的错误，请参考这个。

PS： – 对于您所编辑的问题：

第10行： if (!pipe) return (char*)"ERROR";

第12行： char *result = new char[1024];

第53行:(在第7行中更改） char* getlistOfProcesses(const char* cmd)

有点建议：使用wait(NULL); 在读取listOfProcesses和exit(0);之前的父进程中exit(0); 在子进程结束时。

工作代码：

 #include <stdio.h> #include <unistd.h> #include <cstring> #include <stdlib.h> #include <iostream> #include <sys/wait.h> char* getlistOfProcesses(const char* cmd) { FILE* pipe = popen(cmd, "r"); if (!pipe) return (char*)"ERROR"; char buffer[128]; char *result = new char[1024]; while(!feof(pipe)) { if(fgets(buffer, 128, pipe) != NULL) strcat(result, buffer); } pclose(pipe); return result; } int spawnGEdit() { pid_t gPid = fork(); if(gPid == 0) { execl("gedit", "gedit", NULL); exit(-1); } else { } return 0; } int main(int argc, char **argv) { int P2C[2]; int C2P[2]; pipe(P2C); pipe(C2P); pid_t cPid = fork(); char cmd[50]; char* listOfProcesses = new char[1024]; spawnGEdit(); if (cPid == 0) { close(P2C[1]); close(C2P[0]); read(P2C[0], cmd, 10); if(strcmp(cmd,"LISTALL") == 0) { write(C2P[1], getlistOfProcesses("ps"), 1024); close(P2C[0]); close(C2P[1]); } exit(0); } else if (cPid > 0) { close(C2P[1]); close(P2C[0]); write(P2C[1], "LISTALL", 10); wait(NULL); read(C2P[0], listOfProcesses,1024); printf("%s",listOfProcesses); //TODO //get user input of a PID //kill the PID close(C2P[0]); close(P2C[1]); } else { // fork failed printf("Forking failed!\n"); exit(1); } return 0; }