CODEWITHSUNDEEP
linuxbashshellcommand-line
ViniciusArruda
ViniciusArruda

Reputation: 990

set bash variable from two nested programs

I need to run many times an aplication and get some statistcs using some commands. A simple exemple of what I'm traying to do is:

/usr/bin/time --format="%U" date

This line will print:

Seg Nov  2 22:15:28 BRST 2015
0.00

I need to format this output, and I want to do this using bash, like this:

echo "$usertime & $date"

where $usertime is the result from /usr/bin/time --format="%U" and $date the result of date

I know that the below works, but I don't know how to separate the values into two variables:

OUTPUT=`/usr/bin/time --format="%U" date`
echo "$OUTPUT"

the output from above is:

0.00
Seg Nov  2 22:23:50 BRST 2015

(in reverse order)

Upvotes: 1

Views: 63

Answers (2)

John1024
John1024

Reputation: 113924

Using awk

Here, awk is used to reverse the line order and format the output:

$ /usr/bin/time --format="%U" date 2>&1 | awk 'NR==1{d=$0;next} {print $0 " & " d}'
0.00 & Mon Nov  2 16:58:40 PST 2015

Using sed

$ /usr/bin/time --format="%U" date 2>&1 | sed -E 'N; s/([^\n]*)\n(.*)/\2 \& \1/'
0.00 & Mon Nov  2 17:01:15 PST 2015

Using shell

$ /usr/bin/time --format="%U" date 2>&1 | ( read d; read t; echo "$t & $d" )
0.00 & Mon Nov  2 17:04:40 PST 2015

Upvotes: 1

Alec
Alec

Reputation: 653

/usr/bin/time is writing the time to standard error, whereas the output of date is going to standard output. If you want them in separate variables, you can write the output of time to a file with the -o flag, then read it back in to another variable:

OUTPUT=`/usr/bin/time -o timefile --format="%U" date`
TIME=$(<timefile)

Upvotes: 0

Related Questions