Linux 调用系统命令并截获标准输出(stdout)和错误输出(stderr)

char ret[1024];
char *DoSysCmd(char * cmdline){
    FILE *fp;
    char line[32];
    char cmdtmp[256];
    memset(cmdtmp,0x00,256);
    sprintf(cmdtmp,"%s  2>&1",cmdline);//stderr是2，把2转向1
    memset(ret,0x00,sizeof(ret));
    fp = popen(cmdtmp, "r");
    while ( fgets( line, sizeof(line), fp))
    {
        sprintf(ret ,"%s%s",ret,line);
    }
    pclose(fp);
    return ret;
}

使用例子 

show_Info("检查是否存在可移动存储设备......");
result=DoSysCmd("cat /proc/scsi/scsi");
if (0==strcmp(result,"Attached devices: none\n"))
{
    show_Info("对不起，没有发现任何设备！");
    return;
}