Paul, I think you are comparing apples to oranges. DISP= can be specified in JCL, the program isn't coded using DISP=OLD, it is inherited. In addition, as DISP=OLD is the default, if the JCL coder omits the DISP clause on the JCL, OLD is assumed. And then if there isn't a shell interface to flock() (I don't know if there is one or not), that is a major difference between UNIX and z/OS.
=============================================== Wayne Driscoll OMEGAMON DB2 L3 Support/Development wdrisco(AT)us.ibm.com =============================================== From: Paul Gilmartin <[email protected]> To: [email protected] Date: 07/02/2010 09:01 AM Subject: Re: Unix systems and Serialization mechanism Sent by: IBM Mainframe Discussion List <[email protected]> On Fri, 2 Jul 2010 07:19:24 -0500, McKown, John wrote: > >No. UNIX does not have that functionality. I've looked for it. The closest is called an "advisory lock". This is the flock() function in UNIX. But all programs which access the file must code the flock() themselves. > Even as all z/OS programs desiring serialization must code DISP=OLD themselves. The UNIX kernel provides internal serialization sufficient to prevent directory corruption (as z/OS protects VTOCs). Neither UNIX nor z/OS protects against data corruption except by various elective mechanisms. >http://linux.about.com/library/cmd/blcmdl2_flock.htm > Is there a shell interface to flock()? Is the lock automatically freed when the requesting process terminates, for whatever cause? -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
