Linux 发送信号的时间域命令似乎不起作用

我一直在试验time命令（/usr/bin/time）。我使time命令如下所示运行

/usr/bin/time -v sleep 30

在另一个终端上，我做了一个

ps-a

并找到了

sleep

进程的PID。现在，我使用

kill-1PID

向睡眠发送一条消息，终止了进程睡眠。由于睡眠是按时间运行的，它列出了资源使用统计信息，如下所示

Command being timed: "sleep 30"
User time (seconds): 0.00
System time (seconds): 0.00
Percent of CPU this job got: 0%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:21.81
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 2160
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 180
Voluntary context switches: 2
Involuntary context switches: 2
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0

然而，令我惊讶的是，信号传递字段的值为0！这怎么可能

编辑：

我没有使用

sleep30

，而是尝试了以下脚本

trap "echo Hello" 1 2
sleep 30

---

现在我对上面的脚本进行计时，并向其发送信号1和2。在这种情况下，信号传递字段仍然为0。这使我得出结论，信号传递字段为0，这不是因为信号未被处理。

我正在使用此程序：

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <signal.h>

volatile unsigned int counter=0;

void exithandler(int signum)
{
_exit(1);
}

void ignorehandler(int signum)
{
counter += signum;
}

int main(int argc, char **argv)
{

int delay;

signal ( SIGHUP, ignorehandler );
signal ( SIGQUIT, exithandler );
for (delay = atoi(argv[1] ); delay > 0; ) {
        delay = sleep( delay);
        }

printf("Counter=%u\n", counter);
return 0;
}

---

时间利用了wait4系统调用。我发现structrusage的一些字段仍然没有维护。ru_nsignals是structrusage中的一个这样的字段。

---

有关详细信息，请参阅此问题的正确答案

我的猜测是，由于睡眠进程未安装处理程序，因此信号从未发送。由于有一个DFLT或IGN处理程序“set”，内核在传递信号之前终止进程。（向一个不存在处理程序的进程发送信号无论如何都是无用的。）@wildplasser我已经编辑了这个问题。我得出的结论是，不处理信号不是发送信号的0值的原因。我在问原因！我知道。我只是想避免您（或其他人）必须重新键入相同的内容。顺便说一句：即使在上面的程序中添加了getrusage（）之后，.ru_nsignals仍然是零。

Plasser@pisbak>$ Counter=11
Command being timed: "./mysleep 20"
User time (seconds): 0.00
System time (seconds): 0.00
Percent of CPU this job got: 0%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:22.56
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 1856
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 163
Voluntary context switches: 13
Involuntary context switches: 1
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
[1]+  Done                    /usr/bin/time -v ./mysleep 20
Plasser@pisbak>$ man getrusage