Chapter 2. MSS Pathnames
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Chapter 2. MSS Pathnames

Table of Contents

Name Description
Directory Behavior
POSIX Shell Pattern Support

Name Description

Each MSS file has a name (also known as the pathname) of 1 to 128 characters associated with it. The name is similar to, but does not have exactly the same semantics as, a POSIX (Unix) pathname. The name has the following components:

  1. A slash (/) character.

  2. A top-level directory, whose value is an uppercase version of an user's UCAR Central Authentication Services (UCAS) account name.

  3. A slash (/) character.

  4. Zero or more directory names, each followed by a slash (/) character.

  5. The basename. The path prefix is the portion of the pathname that is not the basename.

The following restrictions apply:

  1. Names are case sensitive. All printable 7-bit ASCII characters in the range from the space (hex 0x20) to the tilde (~, hex 0x7e) are valid. Use of certain characters, including the space, will require quoting to prevent interpretation by the user's local shell.

  2. Trailing space characters are not allowed.

  3. Trailing slash characters are not allowed, except when used to disambiguate a collided trash file from a collided trash directory.

  4. Multiple consecutive slash characters are not allowed.

  5. The strings consisting of a single period (.) or two periods (..) are not allowed as a directory or basename component.

  6. Only valid UCAS account names of users authorized to access the MSS are permitted as the first directory component.

  7. The path prefix (including the separating slash characters) can only contain a maximum of 126 characters. This means a MSS file name must contain at least one valid character.

  8. The MSS top directory level (also known as the MSS root directory) is not accessible to users. All MSS file or directory names must include a valid UCAS account name as the first component.

Here are some example MSS file names:

Name Comment
/USER/file Only the UCAS account name and basename.
/USER/dir/file UCAS account name, a single directory name, basename.
/USER/a/b/c/file UCAS account name, three subdirectory names, basename.

When MSS files have either been removed or purged, they become trash MSS files. In this case, their names are prefixed with /trash. The trash prefix does not count towards the name length. See Chapter 5, MSS File Life Cycles for more details.

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