UNIX for Advanced & Expert Users

Hello, am not able to subtract timestamps in milliseconds.

I extract the timestamp as a string, and then try to subtract the two, but since it is a string, system just outputs 0

Code:

awk -F"," 'substr($1,0,13) - substr($2,0,013)' File

where $1 and $2 are the timestamps in the format HH:MM:SS.000

I have seen the usage of date -d command, but not sure how to pass it to the command line as arguments to awk.

Note the File contains 1000 rows

Try converting "HH:MM:SS" to seconds. Will the timestamps cross midnight? Month end? Year end?

How should I do that? With the date command? The timestamps wont cross midnight, it begins from midnight until 23:59:59.xxx

Now - how many minutes does an hour have? And how many seconds a minute? Do you know about awk's split command?


BTW, your attempt will print nothing if the hours are the same, and the input line if different.

You can calculate seconds from HH:MM:SS via seconds+(minutes*60)+(hours*60*60)