qt 调用linux系统命令修改系统时间
源码：
void MainWindow::pushButton_clicked()
{
QString str1 = "date -s 04/30/2012";
system(str1.toLatin1().data());
QString str2 = "date -s 10:00:00";
system(str2.toLatin1().data());
//强制写入到CMOS
system("clock -w");
}
运行结果：
date: 无法设置日期2012 04 30 ? 00:00:00 CST
: 不允许的操作
2012 04 29 10:00:00 CST
date: 无法设置日期: 不允许的操作
XView warning: Cannot load font '-b&h-lucida-medium-r-*-*-*-120-*-*-*-*-*-*' (Font package)
XView warning: Cannot load font '-b&h-lucida-medium-r-normal-sans-*-120-*-*-*-*-*-*' (Font package)
XView error: Cannot open connection to window server: :0.0 (Server package)
同步系统时钟与硬件时钟时间命令:
硬件时钟同步到系统时钟:hwclock --hctosys
如果：将system("clock -w"); 改为system("hwclock --hctosys");
则：
date: 无法设置日期2012 04 30 ? 00:00:00 CST
: 不允许的操作
2012 04 29 10:00:00 CST
date: 无法设置日期: 不允许的操作
Sorry, only the superuser can change the System Clock.
如果：将system("clock -w"); 改为system("hwclock -systohc");
则：
系统时钟同步到硬件时钟:hwclock -systohc
date: 无法设置日期: 不允许的操作
2012 04 30 ? 00:00:00 CST
2012 04 29 10:00:00 CST
date: 无法设置日期: 不允许的操作
hwclock：无效选项 -- y
hwclock - query and set the hardware clock (RTC)
Usage: hwclock [function] [options...]
Functions:
-h | --help show this help
-r | --show read hardware clock and print result
--set set the rtc to the time given with --date
-s | --hctosys set the system time from the hardware clock
-w | --systohc set the hardware clock to the current system time
--systz set the system time based on the current timezone
--adjust adjust the rtc to account for systematic drift since
the clock was last set or adjusted
--getepoch print out the kernel's hardware clock epoch value
--setepoch set the kernel's hardware clock epoch value to the
value given with --epoch
--predict predict rtc reading at time given with --date
-v | --version print out the version of hwclock to stdout
Options:
-u | --utc the hardware clock is kept in UTC
--localtime the hardware clock is kept in local time
-f | --rtc=path special /dev/... file to use instead of default
--directisa access the ISA bus directly instead of /dev/rtc
--badyear ignore rtc's year because the bios is broken
--date specifies the time to which to set the hardware clock
--epoch=year specifies the year which is the beginning of the
hardware clock's epoch value
--noadjfile do not access /etc/adjtime. Requires the use of
either --utc or --localtime
--adjfile=path specifies the path to the adjust file (default is
/etc/adjtime)
--test do everything except actually updating the hardware
clock or anything else
-D | --debug debug mode
这是怎么回事呢？我QT 不是以root权限运行的
qt 怎样切换到root权限呢？
[解决办法]
sudo ./yourapp
权限是对当前用户的限定，和程序本身无关。
