19.1. Pathname Components

19.1. Pathname Components
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19.1. Pathname Components [sec_19-2-1]

19.1.1. Directory canonicalization
19.1.2. Platform-specific issues

When a pathname is to be fully specified (no wildcards), that means that no :WILD, :WILD-INFERIORS is allowed, no wildcard characters are allowed in the strings, and name EQ NIL may not be allowed either.

19.1.1. Directory canonicalization

As permitted by the MAKE-PATHNAME specification, the PATHNAME directory component is canonicalized when the pathname is constructed:

"" and "." are removed
"..", "*", and "**" are converted to :UP, :WILD and :WILD-INFERIORS, respectively
patterns foo/../ are collapsed

19.1.2. Platform-specific issues

Platform Dependent: UNIX platform only.

Pathname components

host

always NIL

device

always NIL

directory = (startpoint . subdirs)

element	values	meaning
`startpoint`	`:RELATIVE` \| `:ABSOLUTE`
`subdirs`	`()` \| `(subdir . subdirs)`
`subdir`	`:WILD-INFERIORS`	`**` or `...`, all subdirectories
`subdir`	`SIMPLE-STRING`, may contain wildcard characters `"?"` and `"*"` (may also be specified as `:WILD`)

name type

NIL or SIMPLE-STRING, may contain wildcard characters "?" and "*" (may also be specified as :WILD)

version

NIL or :WILD or :NEWEST (after merging the defaults)

A UNIX filename is split into name and type.

External notation:	`"server:sub1.typ/sub2.typ/name.typ"`
using defaults:	`"sub1.typ/sub2.typ/name.typ"`
or	`"name.typ"`
or	`"sub1.typ/*/sub3.typ/x.lisp"`
or similar.

Platform Dependent: Win32 platform only.

Pathname components

host

NIL or SIMPLE-STRING, wildcard characters may occur but do not act as wildcards

device

NIL or :WILD or A|...|Z

directory = (startpoint . subdirs)

element	values	meaning
`startpoint`	`:RELATIVE` \| `:ABSOLUTE`
`subdirs`	`()` \| `(subdir . subdirs)`
`subdir`	`:WILD-INFERIORS`	`**` or `...`, all subdirectories
`subdir`	`SIMPLE-STRING`, may contain wildcard characters `"?"` and `"*"` (may also be specified as `:WILD`)

name type

NIL or SIMPLE-STRING, may contain wildcard characters "?" and "*" (may also be specified as :WILD)

version

NIL or :WILD or :NEWEST (after merging the defaults)

If host is non-NIL, device must be NIL.

A Win32 filename is split into name and type.

External notation:	`"A:\sub1.typ\sub2.typ\name.typ"`
using defaults:	`"\sub1.typ\sub2.typ\name.typ"`
or	`"name.typ"`
or	`":\sub1.typ\\sub3.typ\x.lisp"`
or similar.

Instead of "\" one may use "/", as usual for DOS calls.

If host is non-NIL and the directory's startpoint is not :ABSOLUTE, (PARSE-NAMESTRING (NAMESTRING pathname)) will not be the same as pathname.

Platform Dependent: UNIX, Win32 platforms only.: The wildcard characters: "*" matches any sequence of characters, "?" matches any one character.

Name/type namestring split.

Platform Dependent: UNIX, Win32 platforms only.

A filename is split into name and type according to the following rule:

if there is no "." in the filename, then the name is everything, type is NIL;
if there is a ".", then name is the part before and type the part after the last dot.
if the only "." is the first character, then the behavior depends on the value of the user variable CUSTOM:*PARSE-NAMESTRING-DOT-FILE* which can be either
:TYPE
NIL name, everything after the "." is the type; or
:NAME
NIL type, everything is the name

Note

Due to this name/type splitting rule, there are pathnames that cannot result from PARSE-NAMESTRING. To get a pathname whose type contains a dot or whose name contains a dot and whose type is NIL, MAKE-PATHNAME must be used. Example: (MAKE-PATHNAME :NAME "foo.bar").

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