Technical data

C
How NFS Converts File Names
The NFS to OpenVMS file name translation rules in Table C–1 are based on the
character mapping scheme in Table C–2. The OpenVMS to NFS mapping rules
are the converse of these rules.
Table C–1 NFS Server to OpenVMS Client File Name Conversion Rules
Rule What Happens to File Names from NFS to OpenVMS
1 Lowercase characters become uppercase (unless Rule 2 applies). For example,
file becomes FILE.;1
2 Initial uppercase characters or a sequence of case-shifted characters are
prefixed with the "$" escape character. For example,
CaseShiftedFile
becomes $C$ASE$S$HIFTED$F$ILE.;1
3 A file without a version gets a version number preceded by a semicolon. For
example,
file becomes FILE.;1
4 If a file name does not include a dot (.), a dot is added before the version
number semicolon. For example,
file becomes FILE.;1
5 After its name is converted, a file will not appear in an OpenVMS directory
listing if any one of the following criteria are met:
• The file name is more than 39 characters long.
• The file extension is more than 39 characters long.
• The version number is greater than 32767.
6 If the file name has a dot, the dot is preserved unless the resulting file name
fails one of the tests in Rule 5; if so, the dot becomes "$5N" and the same
rule applies to each subsequent dot found. For example,
more.file.text
becomes MORE.FILE$5NTEXT;1
7 If the file name is a directory, each dot becomes "$5N" and the file name
gets the ".DIR" extension. For example,
dot.directory.list becomes
DOT$5NDIRECTORY$5NLIST.DIR;1
8 Invalid OpenVMS characters become the escape character sequences in the
second column of Table C–2 ("$" followed by a digit and a letter). For example,
special#character&file becomes SPECIAL$5CCHARACTER$5FFILE.;1
("#" becomes "$5C" and "&" becomes "$5F")
9 Any existing "$" becomes "$$" (plus any "$" added due to Rule
2 or 8 above). For example,
dollar$Sign$5cfile becomes
DOLLAR$$$S$IGN$$5CFILE.;1
Table C–2 provides a complete list of OpenVMS character sequences,
corresponding server characters, and octal values used for NFS name
conversion.
How NFS Converts File Names C–1