Welcome!

Linux Containers Authors: Liz McMillan, Carmen Gonzalez, Elizabeth White, Yeshim Deniz, Automic Blog

Related Topics: Linux Containers, Open Source Cloud

Linux Containers: Blog Feed Post

Things You May or May Not Know About Linux “find” Command

How to utilize find in a less common but very useful way

In the first part of our series we described how to use find (and locate) to search for files using their names. Today we are going to review how to utilize find in a less common but very useful way. But first a few words on testing (okay, this might not be necessary for everyone, but bear with me!).

1. How to test
It is very important to remember that the find command allows you to create a list of objects having the value of a property the same, greater or smaller then given “n” — which stands for a number of days defined as 24 hours periods, with any frictional part ignored:

  • +n – value of file property grater than n,
  • n – value of file property the same as n,
  • -n – value of file property smaller than n.

2. Search using time related information.
One of the most useful features of find is the ability to separate files based on the time of their creation, access and modification. This is done by the family of “time” tests. In “n” language, 47 hours will be given the same value as 25 hours (n=1). This behaviour can be changed by adding the option “-daystart” (measure time from beginning of today, so “n” for yesterday equals 1 in front of a test. Have a look at these time definitions below:

  • -mtime n (Modification TIME) – probably the most useful from time-related tests, allowing to search files based on their modification time. If you want to have a list of all log files modified 2 days ago (or to be precise between 48 and 72 hours ago) you can run:
    find /var/log -mtime 2
  • -atime n (Access TIME) – the results based on a file’s last access time. If you want to see all logs accessed today you can run:
    find /var/log -atime 0

    Please remember it might be misleading if you check the file system mounted with option -noatime (which improves performance).

  • -ctime n ([status] Change TIME) – this test searches files based on change of status (It means ownership, access privileges or type). For example you want to find which (or any at all) of the files in your home directory have changed status in the last 48 hours (which might indicate problems) you can run:
    find ~ -ctime -1

Measuring time in days is not always very handy. Sometimes it is necessary to find more recent changes. To make it possible, the above test has minuets-base equivalents:

  • -mmin n – test modification time but in minutes rather than days;
  • -amin n – test access time but in minutes rather than days;
  • -cmin n – test status change time but in minutes rather than days.

Imagine the following situation: You have downloaded a file under five minutes ago, but you are not sure where you have saved it. You can try the following command:

find ~ -mmin -5

In this scenario mmin can be change to amin or cmin, because all “three times” have the same initial value.

Lastly, there are tests allow you to search files in relation to a property of another file. For example:

  • -newer file – returns files modified more recently than the given file,
  • -anewer file – return files accessed more recently than the given file,
  • -cnewer file – return files with the status changed more recently than for the given file.

For example, the following command will list all files accessed later than file DSCF1002.avi in directory /home/movies:

find /home/movies -anewer DSCF1002.avi

There is also a fourth ‘newer’ test:

  • -newerXY reference – which compares timestamp with the given timestamp of the reference file. XY has to be substituted by one or two from the following timestamp type:
    • a – access time,
    • B – birth (creation) time,
    • c – inode status change time,
    • m – modification time,
    • t – reference is interpreted directly as a time.

Please remember that not all combinations are supported (notable X cannot equal t) and B is not supported on all systems. For example, to get the list of all files accessed in /var/cache later than (in BST) July 20th 10:45:32  2011:

find /var/cache -newerat ‘Jul 20 10:45:32 BST 2011’

To create another list with files modified later than the last access to your .profile file:

find /var/cache -newerma ~/.profile

There is one more test that allows you to search based on a time-related parameter:

  • -used n – creates the list of files accessed “n” days after its status was last changed. To find not very often accessed files (let say one month) in /var directory, use this command:
    find /var/ -used +30

Appendix. ls and time
You can try to create similar lists with a little help from the ls command. There are three ls commands that correspond to the above find test. They allow you to sort files according to:

  • -t – modification time (mtime);
  • -u – access time (atime);
  • -c – status change time (ctime).

Option -t simply sorts by modification time, but option -u and -c behave different in connection with other options:

  • ls -u – sorts by access time (receptively ls -c sorts by status change time);
  • ls -ul – shows access time but sorts by name (ls -cl – shows status change time but sorts by name);
  • ls -ult – shows and sorts by access time (ls -clt – shows and sorts by status change time).

Read the original blog entry...

More Stories By Hovhannes Avoyan

Hovhannes Avoyan is the CEO of PicsArt, Inc.,

@ThingsExpo Stories
@GonzalezCarmen has been ranked the Number One Influencer and @ThingsExpo has been named the Number One Brand in the “M2M 2016: Top 100 Influencers and Brands” by Analytic. Onalytica analyzed tweets over the last 6 months mentioning the keywords M2M OR “Machine to Machine.” They then identified the top 100 most influential brands and individuals leading the discussion on Twitter.
The Internet of Things is clearly many things: data collection and analytics, wearables, Smart Grids and Smart Cities, the Industrial Internet, and more. Cool platforms like Arduino, Raspberry Pi, Intel's Galileo and Edison, and a diverse world of sensors are making the IoT a great toy box for developers in all these areas. In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists discussed what things are the most important, which will have the most profound e...
Five years ago development was seen as a dead-end career, now it’s anything but – with an explosion in mobile and IoT initiatives increasing the demand for skilled engineers. But apart from having a ready supply of great coders, what constitutes true ‘DevOps Royalty’? It’ll be the ability to craft resilient architectures, supportability, security everywhere across the software lifecycle. In his keynote at @DevOpsSummit at 20th Cloud Expo, Jeffrey Scheaffer, GM and SVP, Continuous Delivery Busin...
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
@ThingsExpo has been named the Most Influential ‘Smart Cities - IIoT' Account and @BigDataExpo has been named fourteenth by Right Relevance (RR), which provides curated information and intelligence on approximately 50,000 topics. In addition, Right Relevance provides an Insights offering that combines the above Topics and Influencers information with real time conversations to provide actionable intelligence with visualizations to enable decision making. The Insights service is applicable to eve...
SYS-CON Events announced today that Grape Up will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct. 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Grape Up is a software company specializing in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market across the U.S. and Europe, Grape Up works with a variety of customers from emergi...
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place June 6-8, 2017, at the Javits Center in New York City, New York, is co-located with 20th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry p...
Bert Loomis was a visionary. This general session will highlight how Bert Loomis and people like him inspire us to build great things with small inventions. In their general session at 19th Cloud Expo, Harold Hannon, Architect at IBM Bluemix, and Michael O'Neill, Strategic Business Development at Nvidia, discussed the accelerating pace of AI development and how IBM Cloud and NVIDIA are partnering to bring AI capabilities to "every day," on-demand. They also reviewed two "free infrastructure" pr...
New competitors, disruptive technologies, and growing expectations are pushing every business to both adopt and deliver new digital services. This ‘Digital Transformation’ demands rapid delivery and continuous iteration of new competitive services via multiple channels, which in turn demands new service delivery techniques – including DevOps. In this power panel at @DevOpsSummit 20th Cloud Expo, moderated by DevOps Conference Co-Chair Andi Mann, panelists will examine how DevOps helps to meet th...
SYS-CON Events announced today that Hitachi, the leading provider the Internet of Things and Digital Transformation, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Hitachi Data Systems, a wholly owned subsidiary of Hitachi, Ltd., offers an integrated portfolio of services and solutions that enable digital transformation through enhanced data management, governance, mobility and analytics. We help globa...
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal ...
Multiple data types are pouring into IoT deployments. Data is coming in small packages as well as enormous files and data streams of many sizes. Widespread use of mobile devices adds to the total. In this power panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists will look at the tools and environments that are being put to use in IoT deployments, as well as the team skills a modern enterprise IT shop needs to keep things running, get a handle on all this data, and deli...
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend @CloudExpo | @ThingsExpo, June 6-8, 2017, at the Javits Center in New York City, NY and October 31 - November 2, 2017, Santa Clara Convention Center, CA. Learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
SYS-CON Events announced today that SoftLayer, an IBM Company, has been named “Gold Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. SoftLayer, an IBM Company, provides cloud infrastructure as a service from a growing number of data centers and network points of presence around the world. SoftLayer’s customers range from Web startups to global enterprises.
SYS-CON Events announced today that Juniper Networks (NYSE: JNPR), an industry leader in automated, scalable and secure networks, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Juniper Networks challenges the status quo with products, solutions and services that transform the economics of networking. The company co-innovates with customers and partners to deliver automated, scalable and secure network...
The buzz continues for cloud, data analytics and the Internet of Things (IoT) and their collective impact across all industries. But a new conversation is emerging - how do companies use industry disruption and technology enablers to lead in markets undergoing change, uncertainty and ambiguity? Organizations of all sizes need to evolve and transform, often under massive pressure, as industry lines blur and merge and traditional business models are assaulted and turned upside down. In this new da...
SYS-CON Events announced today that Hitachi, the leading provider the Internet of Things and Digital Transformation, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Hitachi Data Systems, a wholly owned subsidiary of Hitachi, Ltd., offers an integrated portfolio of services and solutions that enable digital transformation through enhanced data management, governance, mobility and analytics. We help globa...
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy.
SYS-CON Events announced today that Super Micro Computer, Inc., a global leader in compute, storage and networking technologies, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Supermicro (NASDAQ: SMCI), the leading innovator in high-performance, high-efficiency server technology, is a premier provider of advanced server Building Block Solutions® for Data Center, Cloud Computing, Enterprise IT, Hadoop/...