我正在尝试执行以下命令并读取它的输出。
/usr/sbin/system_profiler SPHardwareDataType | grep 'Serial Number'
我必须execve直接使用（否popen）。我相信我在最后一步失败了，将第二个孩子的输出读入父母的缓冲区。我收到“阅读问题”消息。
char *cmd1[] = {"system_profiler", "SPHardwareDataType", 0};
char *cmd2[] = {"grep", "'Serial Number'", 0};
pid_t pid;
int pipe1[2];
int pipe2[2];
int ret;
pipe(pipe1);
// first child
pid = fork();
if (pid < 0) {
return;
}
if (pid == 0) {
close(pipe1[0]); // close read-end
dup2(pipe1[1], 1); // copy write-end over stdout
close(pipe1[1]); // close write-end
execve("/usr/sbin/system_profiler", cmd1, NULL);
exit(1);
}
pipe(pipe2);
// second child
pid = fork();
if (pid < 0) {
return;
}
if (pid == 0) {
// handle connection between first and second child
close(pipe1[1]); // close write-end
dup2(pipe1[0], 0); // copy read-end over stdin
close(pipe1[0]); // close read-end
// handle connection between second child and parent
close(pipe2[0]); // close read-end
dup2(pipe2[1], 1); // copy write-end over stdout
close(pipe2[1]); // close write-end
execve("/usr/bin/grep", cmd2, NULL);
exit(1);
}
close(pipe1[0]);
close(pipe1[1]);
close(pipe2[1]);
ret = read(pipe2[0], buffer, 128);
if (ret <= 0) {
printf("Reading problem!\n");
return;
}
buffer[ret] = '\0';
printf("Buffer: %s\n", buffer);