php - How to append a timestamp to each line as it comes out of grep?

Question

I have an infinite stream of data coming out of a logger, which I am piping to grep. I would like to save the output of the grep to a file, but also include a timestamp at the beginning of each line (the time at which the line appeared). Is there an easy way to accomplish this? Assume I cannot change the output of the logger process.

Answer 1

您可以使用and附加静态时间戳：seddate

... | sed "s/^/$(date) /" >> output.txt

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或者，如果您需要实时时间戳gawk，请使用strftime 函数：

... | gawk '{ print strftime(), $0 }'

您可以定义自己喜欢的格式：

... | gawk '{ print strftime("%Y-%m-%d %H:%M:%S"), $0 }'

如果缓冲是一个问题，不要忘记刷新每一行：

... | awk '{ print strftime("%Y-%m-%d %H:%M:%S"), $0; fflush() }'

或者，使用unbuffer：

unbuffer ... | awk '{ print strftime("%Y-%m-%d %H:%M:%S"), $0 }'

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如果你没有gawk，你有几个其他的选择：

(a) 安装ts（来自moreutils）：

... | ts '%F %T'

(b) 使用perl：

... | perl -pe 's/^/localtime . " "/e'

或格式：

... | perl -MPOSIX -pe 's/^/strftime("%Y-%m-%d %H:%M:%S", localtime) . " "/e'

不要忘记，如果您需要将 GMT 格式化为您的语言环境，您可以使用gmtime而不是。localtime

(c)问一个问题。