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.
Related
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 tried to measure execution time and format it with this command:
time -f "%e" ./1 1000 1
-f: command not found
real 0m0.066s
user 0m0.044s
sys 0m0.023s
But such command works:
/usr/bin/time -f "%e" ./1 1000 1
31245 212 443
0.00
I tried to determine where another time is located, but all showes to /usr/bin/time
which time
/usr/bin/time
or
whereis time
time: /usr/bin/time /usr/bin/X11/time /usr/include/time.h /usr/share/man/man7/time.7.gz /usr/share/man/man2/time.2.gz /usr/share/man/man1/time.1.gz
or
type -a time
time is a shell keyword
time is /usr/bin/time
How to define where another time is located?
Users of the bash shell need to use an explicit path in order to run
the external time command and not the shell builtin variant. On system
where time is installed in /usr/bin, the first example would become
/usr/bin/time wc /etc/hosts
OR
Note: some shells (e.g., bash(1)) have a built-in time command that
provides less functionality than the command described here. To
access the real command, you may need to specify its pathname
(something like /usr/bin/time).
http://man7.org/linux/man-pages/man1/time.1.html
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
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