john-dev - basename portability 'fix'.

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Date: Mon, 18 Mar 2013 15:40:54 -0500
From: "jfoug" <jfoug@....net>
To: <john-dev@...ts.openwall.com>
Subject: basename portability 'fix'.

Here is a proper running basename.  I build both a 'normal' basename, and a
thread safe one.  The 'normal' one, simply has a static buffer that it
passes into the thread safe one.    the reason for the buffer, is I chose to
have the name param be a const char *.  Some basename's have only a char *,
and document that the function can mess with the param. BBAAADDDD, but they
do that.   Looking at many implementations of basename, it looks like about
50% of them have very bad side effects, or simply do not work properly.

Here is the function proto's  (I put these into misc.c/h

char *jtr_basename(const char *name)

char *jtr_basename_r(const char *name, char *buf)  (buf must be
strlen(name)+1, but PATH_BUFFER_SIZE+1 can also be used.

Here are the 'rules'

a null name, or name pointing to a length 0 string  returns "."

Both Win32 ('\\') and unix ('/') separator chars are handled.  In unix
builds, only the / is handled. In win32, 'both' are handled, since they
actually mean the same thing.

if string is only / or \ chars, then a single / or \ will be returned.

Win32/DOS drive letters are handled.  NOTE, a C: by itself, is treated like
a string of length 0, and returns "."

Trailing / or \ are removed from final basename, IIF there is a basename.

This is made against bleeding (since a code freeze is on, I think on the new
jumbo).  It likely will patch to the jumbo easily, IF someone wants to do
that also.

To use this, simply do this:

#include "misc.h"

char *p = jtr_basename(fullname);

To  use this IF there were in code that had to be thread safe, the
jtr_basename_r() function could be used.  I do not foresee that need
currently, but it is there, since this function needs either a static
buffer, OR needs the input parameter to be able to be destroyed.

Jim.

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