Re: how to handle open() of ifs file and checking if busy

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

Jim,

There are flags named O_SHARE_xxx (where xxx refers to a particular 
sharing style) that can be used to 'lock' the file.  However, since you 
aren't using them in your example, this code will not tell you if a file 
is "busy".  The way you've coded it it will be perfectly happy to use a 
file that's in use, or even deleted, by other jobs.

Here are some suggestions:

1) Please consider using O_CCSID instead of O_CODEPAGE.

2) You are opening/creating a new file, but telling it that the code 
page is 819.  Is the data in your RPG program really already in ASCII? 
Assuming this file contains text, please consider using O_TEXTDATA, 
O_TEXT_CREAT, and giving it both the program and file CCSID.

3) Instead of hard-coding the file's "mode" (authorities) please 
consider using O_INHERITMODE to inherit the authorities. It makes it so 
much easier for an administrator to control authorities when they aren't 
hard-coded in individual programs!

4) You are giving everyone execute access to the file, which means 
someone can try to /run/ it.  That might make sense if you're writing 
something like a shell script to be run in QShell or PASE, but it could 
also be a mistake, so I thought I'd point it out.

-SK



On 6/16/2016 8:21 AM, Jim Franz wrote:
> c                   eval      fd = open(%trim(filename):
> c                                  O_CREAT+O_WRONLY+O_CODEPAGE:
> c                                  S_IRWXO+S_IRWXU+S_IRWXG:
> c                                  819)
> c                   if        fd < 0
> c                   callp     die('open(): ' + %str(strerror(errno)))
> c                   eval      @errflag='Y'
> c                   endif
>
> Where can I find the list of values returned from open() so I can code for
> a busy issue?
> (This is early 2000's code copied from Scott's samples.
>
> Jim Franz