grep - filter twice?

kdar · 2012-05-18 14:26:56

I want to be able to filter time output so that I would only output numbers for real time.

Typical output of time is :

user@user-VirtualBox:~$ time gzip -fc -1 rafale.bmp > rafale.bmp.gz

real	0m0.331s
user	0m0.156s
sys	0m0.060s

By using grep, to filter for "real", I get this:

armen@armen-VirtualBox:~$ (time gzip -fc -1 rafale.bmp > rafale.bmp.gz) 2>&1 | grep real
real	0m0.280s

How can I get only the 0.280? without "real"

Last edited by kdar (2012-05-18 14:27:28)

firecat53 · 2012-05-18 14:35:59

4th item for this google search.

Scott

Trilby · 2012-05-18 14:38:16

 <your command> | awk '/real/ {print $2}'

Or if you want to also drop the minutes, the 'm' and the 's':

<your command> | awk '/real/ {gsub(/0m/,"",$2);gsub(/s/,"",$2);print $2}'

Last edited by Trilby (2012-05-18 14:40:14)

roentgen · 2012-05-18 14:42:33

firecat53 wrote:

4th item for this google search.

It's second item for me . Google isn't as reliable as you try to imply.

skanky · 2012-05-18 14:48:42

This'll cut the 0m0 but not the 's' - you'll need gsub as shown by Trilby for that (I think).

<your command> | awk -Fm '/real/ {print $2}'

Last edited by skanky (2012-05-18 14:49:14)

kdar · 2012-05-18 14:53:53

Thanks everyone.

Does anyone know if I should avoid using time -p? Will it give different results than time?
help time states that -p prints the timing summary in the portable Posix format, however, will the result differ from those of time (without using -p)?

Trilby · 2012-05-18 16:10:10

I don't know much about time ... just ask anyone who's scheduled meetings I'm supposed to show up to! ... ;o)

But you could try both. It seems to me the '-p' drops the minutes, the 'm' and the 's'. So if you just want a clean number, use the '-p' options and use the simpler awk command.

kdar · 2012-05-18 20:07:31

well, if it just for reformatting output, I guess this is ok. But I worry if it calculates real time somehow different with -p.

Arch Linux

#1 2012-05-18 14:26:56

grep - filter twice?

#2 2012-05-18 14:35:59

Re: grep - filter twice?

#3 2012-05-18 14:38:16

Re: grep - filter twice?

#4 2012-05-18 14:42:33

Re: grep - filter twice?

#5 2012-05-18 14:48:42

Re: grep - filter twice?

#6 2012-05-18 14:53:53

Re: grep - filter twice?

#7 2012-05-18 16:10:10

Re: grep - filter twice?

#8 2012-05-18 20:07:31

Re: grep - filter twice?

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