awk - 当我在 awk 中使用 strftime 时，它​​会增加一小时。怎么修

Question

当我尝试将秒数转换为显示 H:M:S 时，awk 中的 strftime 增加了一小时。
为什么以及如何修复？
埃克斯

echo "3600" | awk '{print strftime("%T",$1)}'
02:00:00  # Here i would like to see 01:00:00

echo "60" | awk '{print strftime("%T",$1)}'
01:01:00  # Here i would like to see 00:01:00

这给出了正确的结果，但这正常吗？

echo "72" | awk '{print strftime("%T",int($1)-3600)}'
00:01:12

---

编辑:这是一个解决方法，但我现在仍然想知道为什么 strftime 没有给我正确的答案。

echo "3958" | awk '{h=int($0/3600);m=int(($0-h*3600)/60);s=($0-h*3600-m*60);printf "%02d:%02d:%02d\n",h,m,s}'
01:05:58

echo "64" | awk '{h=int($0/3600);m=int(($0-h*3600)/60);s=($0-h*3600-m*60);printf "%02d:%02d:%02d\n",h,m,s}'
00:01:04

Answer 1

在 GNU awk 中，您可以添加 utc 标志以使用世界时码。

来自手册页:

strftime([format [, timestamp[, utc-flag]]])
  Formats  timestamp  according  to  the  specification  in format.  If utc-flag is present and is non-zero or non-null, the result is in UTC, otherwise the
  result is in local time.  The timestamp should be of the same form as returned by systime().  If timestamp is missing, the current time of  day  is  used.
  If  format  is missing, a default format equivalent to the output of date(1) is used.  See the specification for the strftime() function in ANSI C for the
  format conversions that are guaranteed to be available.

例子:

echo "3600" | awk '{print strftime("%T",$1,1)}'
01:00:00