Re: Looking into C-include files on VMS

Joerg Schilling wrote:
In article <fb6670fc-aac0-4d28-abf1-e7c3c51fcddc@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
Steven Schweda <sms.antinode@xxxxxxxxx> wrote:
John E. Malmberg wrote:

[...]
As long as you are doing an update:

mkiosf is assuming that the host system has the "." and ".." special
directories and exits with an error if they are not present.
[...]
As usual, a _useful_ problem report would include data like
the program version, its origin, and how it was used. The
notes in my latest kit, for example, say:

It seems that he misinterprets the POSIX standard.

- POSIX does not require that a readdir() operation will return entries for "." and "..".

I was referring to the X/Open documentation, not POSIX. VMS does not return entries for "." and ".." from readdir().

But that does not conflict with what I originally posted.

- POSIX however requires that "." and ".." are "understood" by the filesystem in case that there are no explicit entries for "." and
".." in the directories of that filesystem.

The VMS CRTL will accept "." and ".." as expected when calling a routine that knows it is dealing with a directory specification.

If it is dealing with a file specification that could not be a directory it will treat them as files named "." and "..". So it is possible on VMS to create files and directories that in UNIX syntax have the same name.

Again, this does not conflict with what I originally posted.

- The ISO 9660 standard definitely does require directory entries
for "." and "..". ISO 9660 defines the name to be used internally
for "." to be the NULL character with the file name length set to 1.
ISO 9660 defines the name to be used internally for ".." to be
the character '\001' (CONTROL-A) with the file name length set to 1.

When I looked at the ISO 9660 standard, I did not see that. I was paying more attention to what was needed for making a dual format ISO 9660 / ODS-2 volume.

Cleanly written software usually skips the entries for "." and ".." in case they apear as a return from readdir(). Mkisofs was not clean in former times but has been fixed for this problem a long time ago (IIRC in August 2006).

It was about 2005 that I needed a more current port of mkiosf for Alpha/VMS for an internal project.

-John
wb8tyw@xxxxxxxxxxx
Personal Opinion Only
.

Relevant Pages

  • Re: Looking into C-include files on VMS
    ... to be the NULL character with the file name length set to 1. ... When I looked at the ISO 9660 standard, ... Mkisofs was not clean in former times ... Mkisofs did apparently work ...
    (comp.os.vms)
  • Re: Why (or not) use single letter variable names?
    ... But BCPL did use ASCII, ... The 1963 CCITT report on adopting the ISO 7-bit code lists commercial- ... along with up- and left-arrow as a "soft" character in the ISO set ... (Note this document was written by Ritchie and Thompson.) ...
    (comp.lang.c)
  • Re: Ligatures [was: Re: The -s plural in English nouns]
    ... news supports ISO 8859-1 character encoding ... In my original post, ISO 8859-1 and its prevalence in modern computing was discussed. ... Essentially, you're advocating an ASCII-only world - based on a character set that was created only with American needs in mind, 40 years ago. ... XP or Windows 2000, while for 4,384 accesses the operating system ...
    (alt.usage.english)
  • Re: Truncation of fractions in floating-point literals
    ... I will refer to the ISO C which is the same as the ISO C++ in the ... the string is in 932 DBCS and the backslash is a trailing char - not a leading one. ... Each source character ... converted to the corresponding member of the execution character set; ...
    (microsoft.public.dotnet.languages.vc)
  • Re: Matilda SCHRAUMANN
    ... But what does the receiver read on his ... The correct codes are generated and are in the ISO 8859-1 character set. ... but wish to convey the fact that the character has an umlaut. ...
    (soc.genealogy.german)