What is “lock file”?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
0
down vote

favorite












Mark says at https://unix.stackexchange.com/a/467795/




One use for O_EXCL and O_CREAT with open() is to create a simple lock file. If multiple processes try to open the same file with the O_CREAT and O_EXCL flags, one will succeed and the rest will fail. Of course, if the file already exists, for example because a previous process exited without removing the file, none of the subsequent attempts will succeed, so this is not the most robust way to manage a lock.




What does "lock file" mean?



The quote seems to me that the program which creates a lock file should delete it before termination. If so, is a lock file not used for storing meaning data, but for some other purpose?



Thanks.






files io lock






share

























    up vote
    0
    down vote

    favorite












    Mark says at https://unix.stackexchange.com/a/467795/




    One use for O_EXCL and O_CREAT with open() is to create a simple lock file. If multiple processes try to open the same file with the O_CREAT and O_EXCL flags, one will succeed and the rest will fail. Of course, if the file already exists, for example because a previous process exited without removing the file, none of the subsequent attempts will succeed, so this is not the most robust way to manage a lock.




    What does "lock file" mean?



    The quote seems to me that the program which creates a lock file should delete it before termination. If so, is a lock file not used for storing meaning data, but for some other purpose?



    Thanks.






    files io lock






    share























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      Mark says at https://unix.stackexchange.com/a/467795/




      One use for O_EXCL and O_CREAT with open() is to create a simple lock file. If multiple processes try to open the same file with the O_CREAT and O_EXCL flags, one will succeed and the rest will fail. Of course, if the file already exists, for example because a previous process exited without removing the file, none of the subsequent attempts will succeed, so this is not the most robust way to manage a lock.




      What does "lock file" mean?



      The quote seems to me that the program which creates a lock file should delete it before termination. If so, is a lock file not used for storing meaning data, but for some other purpose?



      Thanks.






      files io lock






      share













      Mark says at https://unix.stackexchange.com/a/467795/




      One use for O_EXCL and O_CREAT with open() is to create a simple lock file. If multiple processes try to open the same file with the O_CREAT and O_EXCL flags, one will succeed and the rest will fail. Of course, if the file already exists, for example because a previous process exited without removing the file, none of the subsequent attempts will succeed, so this is not the most robust way to manage a lock.




      What does "lock file" mean?



      The quote seems to me that the program which creates a lock file should delete it before termination. If so, is a lock file not used for storing meaning data, but for some other purpose?



      Thanks.






      files io lock




      files io lock





      share












      share










      share



      share










      asked 2 mins ago









      Tim

      24.2k67233423




      24.2k67233423

























          active

          oldest

          votes











          Your Answer







          StackExchange.ready(function()
          var channelOptions =
          tags: "".split(" "),
          id: "106"
          ;
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function()
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled)
          StackExchange.using("snippets", function()
          createEditor();
          );

          else
          createEditor();

          );

          function createEditor()
          StackExchange.prepareEditor(
          heartbeatType: 'answer',
          convertImagesToLinks: false,
          noModals: false,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: null,
          bindNavPrevention: true,
          postfix: "",
          onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          );



          );













           

          draft saved


          draft discarded


















          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f476166%2fwhat-is-lock-file%23new-answer', 'question_page');

          );

          Post as a guest






















          active

          oldest

          votes













          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes















           

          draft saved


          draft discarded















































           


          draft saved


          draft discarded














          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f476166%2fwhat-is-lock-file%23new-answer', 'question_page');

          );

          Post as a guest
































































          -

          Popular posts from this blog

          How to check contact read email or not when send email to Individual?

          Image
          Clash Royale CLAN TAG #URR8PPP up vote 1 down vote favorite I'm using WordPress 4.9.8, CiviCRM to 5.5.1, I usually send email to contact by Search> Find contacts View contact details Action> Send email Send email ok, Contact received mail ok like picture But status only Email sent though contact read email or not. So, can CiviCRM can change status to Email read when contact read email? wordpress email share | improve this question asked Sep 26 at 0:12 ToanLuong 49 9 add a comment  |  up vote 1 down vote favorite I'm using WordPress 4.9.8, CiviCRM to 5.5.1, I usually send email to contact by Search> Find contacts View contact details Action> Send email Send email ok, Contact received mail ok like picture But status only Email sent though contact read email or not. So, can CiviCRM can change status to Email read when contact read email? wordpress email share | improve this question asked Se
          Read more

          Bahrain

          Image
          For other uses, see Bahrain (disambiguation). Sovereign island state in the Persian Gulf Kingdom of Bahrain مملكة البحرين   (Arabic) Mamlakat al-Baḥrayn Flag Coat of arms Anthem:  نشيد البحرين الوطني Bahrainona Our Bahrain Location of   Bahrain    (circled in red) Capital and largest city Manama 26°13′N 50°35′E  /  26.217°N 50.583°E  / 26.217; 50.583 Official languages Arabic Ethnic groups (2010 [1] ) 50.7% Arab (46% Bahrani, 4.7% other Arabs) 45.5% Asian 1% European 1.2% Others Religion Islam Demonym(s) Bahraini Government Unitary constitutional monarchy • King Hamad bin Isa Al Khalifa • Crown Prince Salman bin Hamad bin Isa Al Khalifa • Prime Minister Khalifa bin Salman Al Khalifa Legislature National Assembly • Upper house Consultative Council • Lower house Council of Representatives Independence • Declared Independence [2] 14 August 1971 • from United Kingdom [1] 15 August 1971 • Admitted to the United Nations 21 September 1971 • Kingdom of Bahrain 14 February 2002
          Read more

          Postfix configuration issue with fips on centos 7; mailgun relay

          Image
          Clash Royale CLAN TAG #URR8PPP up vote 0 down vote favorite I am trying to setup postfix to relay all mail generated on the local machine via SMTP to a mailgun relay. I have used the mailgun relay before with success on an ubuntu server, but I am migrating to a Centos 7 server which I will be running in FIPS mode. There error log is below, slightly sanitized. I have a small enough network that I choose to have each machine reach out to mailgun individually (this the loopback-only, 127.0.0.0/8 restrictions) and no firewall open port allowing smtp in to the machine. I assume the FIPS mode (and with it disabling of MD5) is causing problems, but I don't know how to overcome it or if it is even possible for tls_fprint to use some supported hash such as sha256 or sha512. However, the relay=none is slightly concerning since I have relayhost set, but perhaps that is because the smtp process is failing? Any help would be appreciated! postconf -n: alias_database = hash:/etc/alia
          Read more