I want to find just how long my program takes to run from start to finish in order to compare it with a past version.
How would I go about finding the time it takes for both of these versions? I'm running ubuntu 12.04LTS
Use the time command:
time yourprogram
By default it will output something similar to this:
real 0m0.020s
user 0m0.004s
sys 0m0.000s
real means the total time your program runs. user means the time your program spent in user land code and sys is the time your program spent in kernel calls.
Run time myprogram
The time command will display all the details you need to know.
Example:
rh63-build(greg)~>time ls >/dev/null
real 0m0.003s
user 0m0.001s
sys 0m0.002s
Here is more about the time command: http://linux.die.net/man/1/time
Linux comes with the 'time' program.
$time ./myapp
real 0m0.002s
user 0m0.000s
sys 0m0.000s
Related
system:macos 10.13.6
shell: zsh or bash
node: 10.12.0
In my terminal run : time node -v
real 0m10.197s
user 0m0.006s
sys 0m0.007s
I use time /Users/luxueyan/.nvm/versions/node/v10.12.0/bin/node -v,the result is the same. The real time is 10s.
How can I use a linux command to get the wall time in seconds spent for executing a program. In the example below,I expected to get "0.005".
$ time ls >/dev/null
real 0m0.005s
user 0m0.001s
sys 0m0.003s
Depending on your path:
/usr/bin/time -f "%e"
The normal time is given by bash's (if you happen to use bash) intern time command
type time
while you need the one,
which time
will find.
So in context of your command:
/usr/bin/time -f "%e" ls > /dev/null
But to store it in a variable, you can't use
a=$(/usr/bin/time -f "%e" ls > /dev/null)
because the output of time is written to the error stream, to not inflict with the programs output (in this example ls). See the manpage of time for further details.
When i take my console i get (as the most trivial thing i can invent to execute in Wine)
ubuntu#ip-172-31-15-113:~$ time wine cmd /C echo hello
hello
real 0m0.024s
user 0m0.020s
sys 0m0.000s
which is about as expected, but when i do same from Node subprocess, it takes 4000-5000ms!
var wine=cp.spawn('wine',['cmd', '/C', 'echo','hello'])
i suspect this is because the environment is somehow different for that child process and my command line. what can be the fix?
I have a process I am running via dtach. I would like to measure it's time and write it to a file. let's call the process ls -l.
I've tried several things I saw around but couldn't make it work..
Can anyone help?
time command may help you:
time dtach -c /tmp/foofoo -Ez ls -l
output:
...
...
[EOF - dtach terminating]
real 0m0.005s
user 0m0.000s
sys 0m0.000s
The problem is when I use time in shell I get output like that:
1.350u 0.038s 0:01.45 95.1% 0+0k 0+72io 1pf+0w
And when Im using it in script I get:
real 0m1.253s
user 0m1.143s
sys 0m0.047s
I mean why? And in shell script at the beginning I write:
#!/bin/bash
Bash has a built-in command time, and your system should also have a separate binary at /usr/bin/time:
$ help time
time: time [-p] pipeline
Report time consumed by pipeline's execution.
Execute PIPELINE and print a summary of the real time, user CPU time,
...
$ which time
/usr/bin/time
The two commands produce different outputs:
$ time echo hi
hi
real 0m0.000s
user 0m0.000s
sys 0m0.000s
$ /usr/bin/time echo hi
hi
0.00user 0.00system 0:00.00elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+199minor)pagefaults 0swaps