The time Command on Arch Linux

Okay so I don’t really understand how the time command appears to be both installed and not installed at the same time but I thought I’d post it here in case it save someone some time.

So it appears to be working in so far as you can time how long a command takes to execute. Below I use it to see the ls execution time:

 
andy@home-pc:~$ time ls   

real	0m0.001s
user	0m0.000s
sys	0m0.000s

I only noticed there was an issue because I wanted to see more detailed information, like the Page size but could see that it wasn’t recognising the --verbose parameter.

andy@home-pc:~$ time -v ls
-bash: -v: command not found

real	0m0.001s
user	0m0.000s
sys	0m0.000s

I checked the man page and sure enough – no -v. Weird! So then I thought I’d run the command using the full path just in case. To check where it was located a used which.

[home-pc ~]# which time
which: no time in (/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl)

Hummm, so I looked for the file using the find command and the below is all I found.

[home-pc ~]# find / -name time -type f 
/sys/devices/pnp0/00:01/rtc/rtc0/time
/sys/module/printk/parameters/time
find: ‘/run/user/1000/gvfs’: Permission denied
[home-pc ~]#

So I then decided to try “reinstalling” it only to then find it wasn’t installed at all!

[home-pc ~]# pacman -Sy time

And now everything works as expected!

[home-pc ~]# which time
/usr/bin/time

And now at last I can see the Page size.

[homepc ~]# /usr/bin/time -v ls
vms
	Command being timed: "ls"
	User time (seconds): 0.00
	System time (seconds): 0.00
	Percent of CPU this job got: 100%
	Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.00
	Average shared text size (kbytes): 0
	Average unshared data size (kbytes): 0
	Average stack size (kbytes): 0
	Average total size (kbytes): 0
	Maximum resident set size (kbytes): 1920
	Average resident set size (kbytes): 0
	Major (requiring I/O) page faults: 0
	Minor (reclaiming a frame) page faults: 86
	Voluntary context switches: 1
	Involuntary context switches: 0
	Swaps: 0
	File system inputs: 0
	File system outputs: 0
	Socket messages sent: 0
	Socket messages received: 0
	Signals delivered: 0
	Page size (bytes): 4096

Weird……..and kind of annoying to be honest!

I think the original time command must be a striped-down version included in the kernel. After a bit of researching, seems its a built-in (shell) command of the GNU/Linux Core Utilities.