`time` is a command line utility for running another program and summarizing resource usage

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12
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How to average time commands?

I am timeing some of my commands. Now to average the measures, I'd like to run and time my commands a specified number of times, and get the results with a calculated mean and standard deviation. The ...
13
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1answer
3k views

Why would the “real” time be much higher than the “user” and “sys” times combined?

I execute and time many commands (i.e. nslookup) through SSH and I collect the total time needed for the implied service to complete (i.e. DNS). So I collect the user and sys time as the real time ...
15
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2answers
797 views

Is there something like `time` that also records I/O and CPU?

I can pretty quickly monitor the running time of a process with time: x@y ~ $ time foo real 0m14.299s user 0m4.770s sys 0m0.440s Is there a way I can get the same data for ...
0
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0answers
21 views

Must set CMOS clock to localtime (due to DOS dual boot), timedatectl or hwclock seems to keep setting CMOS (hardware) clock to UTC!

This is beyond crazy. I have a dual-boot system, one OS is FreeDOS (which has NO ability to deal with CMOS clock being anything other than local time), and the other is Linux Mint 17. The way this ...
3
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3answers
323 views

How to sleep until a given date & time?

I want to write a shell where given a date (day-hour-min) e.g. 10:00 AM Sun 2:30 PM Mon ... It sleeps until that exact date & time. I thought one way of doing it is, I could get the current ...
27
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5answers
65k views

How to measure time of program execution and store that inside a variable

In order to find out how long certain operations within a Bash (v4+) script take, I would like to parse the output from the time command "separately" and (ultimately) capture it within a Bash variable ...
0
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1answer
18 views

What service executes that sets up the real time clock

I'm looking for the service that runs that sets up the correct time on my system. Does anyone know what service does this?
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21 views

System time in Minix with best precision

I'm working on a project to modify the scheduler in MINIX 3. So to test it I need to analyse the wait time and turnaround time. To calculate the wait time I'm storing the system time when the process ...
4
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1answer
4k views

Find last shutdown time

This is the command I am using: last -x|grep shutdown | head -1 but it's giving me the duration with +2 hours: shutdown system down 3.14-1-amd64 Mon Jul 21 08:43 - 22:19 (13:36) the last ...
0
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0answers
22 views

Incorrect file creation/modification time

So I run a backup script on a home server running Fedora 23. I also run a prune script that removes files older than 30 days. This fresh backup file keeps getting deleted because it's creation or ...
0
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0answers
31 views

dd process real vs. sys time

I have two quad core workstations. One is based on Intel Atom x86_64 architecture (WS1). Another one is based on armv7l architecture (WS2). Both are running 3.10 kernel version. Identical busybox dd ...
0
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1answer
29 views

Deleting a file after X days does not work [duplicate]

Ive tried multiple ways of writing this and im executing the script myself so it isnt the crontab that isnt working. These are examples of what ive tried : find /home/backups -mtime +1 -exec rm {} \; ...
5
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3answers
382 views

How to measure Firefox's startup time?

I would like to measure how much time it takes for some softwares to start. I know the command time but in the case of firefox (iceweasel for me on Debian), this command prints only the time I let ...
4
votes
2answers
40 views

log of open and close time of a program

I want to get the total time a program was run daily for personal logging (from start to close even if it is in the background). For example: Firefox. Is there a system log that keeps track of open ...
0
votes
2answers
37 views

Resource usage (% CPU) for given command on OS X

The time -v command outputs % CPU utilization for a given command on Linux. How do I do this on OS X? The Linux/OS X difference is illustrated here. I would like to measure multi-core utilization ...
8
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3answers
1k views

Measuring time within a script

This thread shows how to measure the time it takes to run a script. In my case, I am interested in measuring time between two points within a script. Here is an example of how I would like to use ...
10
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3answers
5k views

Why is my EC2 server's time off by ~10 seconds every day?

I have what I believe is a system file, /etc/cron.daily/ntpupdate which runs ntpdate ntp.ubuntu.com daily to sync with the network time. Every day it generates output very similar to this: ...
0
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1answer
42 views

Setting time and date without using NTP

I have a "windriver" linux based Wimax ASN, and when ever I login, I find the date and time is wrong (example: "15 jul 2010"). Whenever I set both the date and time with the date command, or the ...
2
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1answer
58 views

Time synchronization, use NTP or just socket?

I am using a PC and a raspberry pi(both run Linux) to gather sensor data, raspberry pi gathers laser scan data, PC gathers image captured by camera. I must synchronize time for these two machines. I ...
0
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1answer
16 views

Using corrected time in the “attribution” variable of mutt?

I receive quite a few email messages displaying UTC time within the "Date:" header. I found the following perl script by user hyperair, very useful to display a new header "Local-Date" for incoming ...
7
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2answers
14k views

Good method to compare time?

I need to check for the current time and abort the script if it is not proper time of day I am supposed to run it. Also, if anyone else runs it, it should abort. For example: I need my script to only ...
1
vote
1answer
28 views

date: Getting next certain hour

I want to get a date-time string in the future, for example I always want to get the next time of 9:00 am. I know the string formats like "tomorrow" or "next day" to get a certain date-time string. ...
0
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1answer
41 views

Issues with storing an echo of a date conversion into a string variable inunix

Apologies but this question comes from a question previously raised: How can I convert a local date-time into UTC date-time? Toby has been absolutely great helping me with some conversion string-->BST ...
11
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4answers
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Why is scp so slow and how to make it faster?

I'm trying to copy a batch of files with scp but it is very slow. This is an example with 10 files: $ time scp cap_* user@host:~/dir cap_20151023T113018_704979707.png 100% 413KB 413.2KB/s 00:00 ...
5
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3answers
331 views

Unix epoch in milliseconds

I'm prepending the Unix epoch with "nanosecond" precision into output of my command as below: $ command | while read line; do d=`date +%s%N`; echo $d $line; done > file I looked around to find ...
2
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1answer
96 views

Time is not synchronized in Linux VM

I am using one Linux VM through VNC viewer from my Windows machine. What I am seeing is that time between two is not synchronized. It seems that the VM is about 5 minutes delayed from Windows (windows ...
2
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0answers
40 views

What hardware support is needed for linux to do `gettimeofday` / `clock_gettime` in userspace using `hped`?

On reasonably modern systems Linux can service "system" calls like gettimeofday and clock_gettime entirely in userspace through the linux-vdso.so (or linux-gate.so) virtual library, so it does not ...
4
votes
1answer
260 views

CPU is free, yet bash script not utilizing all CPU resources

I ran a simple script to generate a large (10000000 lines) csv file with 6 fields in which some fields changed in each line/row, using a while loop. The machine had all (32) CPUs free, lot of RAM (~31 ...
1
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2answers
52 views

Embedded Debian-Linux, no Timezone

We have a platform with Embedded-Debian-Linux as OS which will be distributed worldwide. We have a Battery-Backed RTC which should be used as system time. We do not want to have any timezone or any ...
0
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2answers
63 views

Does ntpd have a default driftfile?

I have an embedded Linux with busybox's ntpd. My ntpd.conf is tinker panic 0 server pool.ntp.org iburst server 0.pool.ntp.org iburst server 1.pool.ntp.org iburst restrict default kod nomodify notrap ...
0
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0answers
38 views

issues with acpi-cpufreq and frequency scaling

I am using the Ubuntu distribution on Intel(R) Core(TM) i7-2760QM CPU @ 2.40GHz with Kernel version: 3.14.5. I deactivated the intel_pstate driver and activated the acpi-cpufreq driver with userspace ...
2
votes
1answer
728 views

RTC clock time sync with the Linux time on Startup

The RTC remembers its time set, and how does the linux kernel gets this time from dev/rtc and set it as the linux time. In other words on boot up - when does kernel reads the rtc and updates its linux ...
6
votes
1answer
47 views

GNU find -[cma]time option and daylight saving time

In the GNU find man, you can read this about the -atime option: -atime n File was last accessed n*24 hours ago. When find figures out how many 24-hour periods ago the file was last ...
6
votes
3answers
4k views

Sleep until next occurrence of specific time

I need a series of commands or a single command that sleeps until the next occurrence of a specific time like "4:00" occurs. How would I do that? The at command or a cronjob is not a option because ...
1
vote
1answer
153 views

Checking how long a user has been logged in

Is it possible to check for how long a user has been logged in? Or when the user logged in on an Unix/Linux system? I logged in as another user on my system a while ago and I would like to now how ...
2
votes
3answers
47 views

Different 'time's called in similar environments in bash

I was told that people using bash will have to differentiate between the shell-builtin time and /usr/bin/time ( time(1) ). I had to time a program and also had to find ways to automate input, using ...
0
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2answers
38 views

Why I can't use the time command in verbose mode without specifying the whole command path?

Given that... ~$ which time time is a shell keyword time is /usr/bin/time Why this works? ~$ /usr/bin/time --verbose ./some_script.sh Command being timed: "./some_script.sh" User time (seconds): ...
0
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1answer
207 views

How do I run a batch file at a specific time?

I have tried using the batch and at commands with no luck. I have a batch file in a location, lets say "$DD/batchfile.batch". Here is what I have tried. batch -f $DD/batchfile.batch 10:00 today at -f ...
5
votes
1answer
207 views

Using the built-in “time” command in bash rather than the external command

Working with the time command, I came across a situation where I should use the built-in time rather than the external GNU time command /usr/bin/time. So, how can I do this? I saw somewhere that ...
2
votes
1answer
101 views

Is it possible to read PVclock from user space?

Is it possible to read clocksource xen or kvmclock using some user space tool? Referring to /sys/devices/system/clocksource/clocksource0/current_clocksource. Reading the actual value of the pvclock. ...
1
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1answer
231 views

/usr/bin/time command -v not working

I know many questions have been asked/answered about the time command, but mine still seems to be not working. I have been doing like everyone suggests, and using /usr/bin/time, which seems to work, ...
32
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3answers
142k views

Timezone setting in Linux [closed]

I'm setting the timezone to GMT+6 on my Linux machine by copying the zoneinfo file to /etc/localtime, but the date command is still showing the time as UTCtime-6. Can any one explain to me this ...
0
votes
2answers
373 views

How to find out last run time of shell script?

I am trying to find out at what time the shell script ran last time within the shell script. I tried: ls -laru ls -lart but all these commands give me the last modified time and last accessed ...
1
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0answers
36 views

date/time setting does not work after unplugging power adapter or sudden power cut

For some reason, I want to configure the date/time in my Linux (CentOS 6.5) to be different from the REAL date/time, but the setting won't work if I turn my computer(desktop not laptop if this ...
0
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2answers
45 views

Timing start up time for app launched via terminal command

I'd like to see how long it takes a certain app to fully start. Is there a way to do this launching the app via terminal using some command?
28
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3answers
17k views

Why does Unix time start at 1970-01-01

Why does Unix time start at 1970-01-01? Why not 1971-01-01 or any other date?
1
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1answer
77 views

Why is the localtime reset to the default timezone?

I use the following commands to set the timezone on our Amazon Linux (Centos) server: ls -al /etc/localtime -rw-r--r-- 1 root root 118 25 dec 2012 /etc/localtime sudo mv /etc/localtime ...
2
votes
1answer
81 views

Stable timing for shell scripts?

The run times of scripts vary quite much. I would like to find similar time -function as Matlab's timeit, described here. For instance, I am evaluating these commands here about counting quickly ...
14
votes
8answers
47k views

How to check if NTPD updates machine's time successfully using shell?

I'm trying to use NTPD to update my Linux machine's time to a specified NTP server. Here is the scenario: Each time the Linux machine starts up, I want to update the time from NTP server and if ...
7
votes
1answer
163 views

NTP and NTPD Nanokernel

I had a couple of questions about the NTP Nanokernel as explained here: http://www.eecis.udel.edu/~mills/database/brief/nano/nano.pdf The big question is how does this Nanokernel manage to deliver an ...