info/why-linux-is-better
1
0
Fork 0
mirror of https://github.com/nbeaver/why-linux-is-better.git synced 2025-08-26 15:24:25 +02:00
Code Issues Releases Wiki Activity

Move to a footnote with more discussion.

Browse Source
This commit is contained in:
Nathaniel Beaver
2016-02-11 19:40:17 -06:00
parent a18a1f6e83
commit 29387026de
1 changed files with 32 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
readme.rst
View File

@@ -611,15 +611,13 @@ Filename restrictions.
---------------------- ----------------------
In Linux and other Unix-derived operating systems, In Linux and other Unix-derived operating systems,
the only `characters that cannot appear`_ the only characters that may not appear
in the name of a file or directory in the name of a file or directory [#forbidden_characters]_
are the slash ``/``, are the slash ``/``,
which is used to delimit paths, which is used to delimit paths,
and the ASCII null ``\0``, and the ASCII null ``\0``,
which is used to terminate strings in C. [#C_strings]_ which is used to terminate strings in C. [#C_strings]_
.. _characters that cannot appear: https://stackoverflow.com/questions/1976007/what-characters-are-forbidden-in-windows-and-linux-directory-names
Windows has the same restrictions, Windows has the same restrictions,
as well as many other `restrictions which are considerably more complex`_ as well as many other `restrictions which are considerably more complex`_
and are partly the result and are partly the result
@@ -670,6 +668,36 @@ but such restrictions do not apply to filenames.)
.. [#] https://programmers.stackexchange.com/questions/61683/standard-format-for-using-a-timestamp-as-part-of-a-filename .. [#] https://programmers.stackexchange.com/questions/61683/standard-format-for-using-a-timestamp-as-part-of-a-filename
.. [#colons_in_PATH] https://stackoverflow.com/questions/14661373/how-to-escape-colon-in-path-on-unix .. [#colons_in_PATH] https://stackoverflow.com/questions/14661373/how-to-escape-colon-in-path-on-unix
.. [#forbidden_characters]
As discussed in this StackOverflow question:
https://stackoverflow.com/questions/1976007/what-characters-are-forbidden-in-windows-and-linux-directory-names
When Steve Bourne was writing his Unix shell (which came to be known as the
Bourne shell), he made a directory of 254 files with one-character names, one for each
byte value except ``'\0'`` and slash, the two characters that cannot appear in Unix file
names. He used that directory for all manner of tests of pattern-matching and tok-
enization. (The test directory was of course created by a program.) For years after-
wards, that directory was the bane of file-tree-walking programs; it tested them to
destruction.
--- Brian W. Kernighan and Rob Pike, "The Practice of Programming", Chapter 6: Testing, p. 158
https://books.google.com/books?id=j9T6AgAAQBAJ&lpg=PP1&dq=the%20practice%20of%20programming&pg=PA158#v=onepage&q=When%20Steve%20Bourne
This is also explicitly stated in the POSIX standard.
The characters composing the name may be selected from the set of all
character values excluding the slash character and the null byte.
http://pubs.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap03.html
The bytes composing the name shall not contain the <NUL> or <slash>
characters.
http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_170
.. [#C_strings] The wisdom of this decision is a matter of some debate. .. [#C_strings] The wisdom of this decision is a matter of some debate.
Dennis Ritchie has explained the `rationale for using a null-terminator`_: Dennis Ritchie has explained the `rationale for using a null-terminator`_: