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Diffstat (limited to 'winsup/mingw/mingwex/dirname.c')
| -rwxr-xr-x | winsup/mingw/mingwex/dirname.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/winsup/mingw/mingwex/dirname.c b/winsup/mingw/mingwex/dirname.c new file mode 100755 index 000000000..44256b19c --- /dev/null +++ b/winsup/mingw/mingwex/dirname.c @@ -0,0 +1,174 @@ +/* dirname.c + * + * $Id$ + * + * Provides an implementation of the "dirname" function, conforming + * to SUSv3, with extensions to accommodate Win32 drive designators, + * and suitable for use on native Microsoft(R) Win32 platforms. + * + * Written by Keith Marshall <keithmarshall@users.sourceforge.net> + * + * This is free software. You may redistribute and/or modify it as you + * see fit, without restriction of copyright. + * + * This software is provided "as is", in the hope that it may be useful, + * but WITHOUT WARRANTY OF ANY KIND, not even any implied warranty of + * MERCHANTABILITY, nor of FITNESS FOR ANY PARTICULAR PURPOSE. At no + * time will the author accept any form of liability for any damages, + * however caused, resulting from the use of this software. + * + */ + +#include <stdio.h> +#include <string.h> +#include <libgen.h> + +#ifndef __cdecl /* If compiling on any non-Win32 platform ... */ +#define __cdecl /* this may not be defined. */ +#endif + +__cdecl char *dirname( char *path ) +{ + static char retfail[] = "?:."; + char *retname, *basename, *copyptr = retfail; + + if( path && *path ) + { + retname = path; + + /* SUSv3 identifies a special case, where path is exactly equal to "//"; + * (we will also accept "\\" in the Win32 context, but not "/\" or "\/", + * and neither will we consider paths with an initial drive designator). + * For this special case, SUSv3 allows the implementation to choose to + * return "/" or "//", (or "\" or "\\", since this is Win32); we will + * simply return the path unchanged, (i.e. "//" or "\\"). + */ + + if( (*path == '/') || (*path == '\\') ) + { + if( (path[1] == *retname) && (path[2] == '\0') ) + return retname; + } + + /* For all other cases ... + * step over the drive designator, if present, copying it to retfail ... + * (FIXME: maybe should confirm *path is a valid drive designator). + */ + + else if( *path && (path[1] == ':') ) + { + *copyptr++ = *path++; + *copyptr++ = *path++; + } + + if( *path ) + { + /* reproduce the scanning logic of the "basename" function + * to locate the basename component of the current path string, + * (but also remember where the dirname component starts). + */ + + for( retname = basename = path ; *path ; ++path ) + { + if( (*path == '/') || (*path == '\\') ) + { + /* we found a dir separator ... + * step over it, and any others which immediately follow it + */ + + while( (*path == '/') || (*path == '\\') ) + ++path; + + /* if we didn't reach the end of the path string ... */ + + if( *path ) + + /* then we have a new candidate for the base name */ + + basename = path; + + else + + /* we struck an early termination of the path string, + * with trailing dir separators following the base name, + * so break out of the for loop, to avoid overrun. + */ + + break; + } + } + + /* now check, + * to confirm that we have distinct dirname and basename components + */ + + if( basename > retname ) + { + /* and, when we do ... + * backtrack over all trailing separators on the dirname component, + * (but preserve exactly two initial dirname separators, if identical), + * and add a NULL terminator in their place. + */ + + --basename; + while( (basename > retname) && ((*basename == '/') || (*basename == '\\')) ) + --basename; + if( (basename == retname) && ((*retname == '/') || (*retname == '\\')) + && (retname[1] == *retname) && (retname[2] != '/') && (retname[2] != '\\') ) + ++basename; + *++basename = '\0'; + + /* adjust the start point of the dirname, + * to accommodate the Win32 drive designator, if it was present. + */ + + if( copyptr > retfail ) + retname -= 2; + + /* if the resultant dirname begins with EXACTLY two dir separators, + * AND both are identical, then we preserve them. + */ + + path = copyptr = retname; + while( ((*path == '/') || (*path == '\\')) ) + ++path; + if( ((path - retname) == 2) && (*++copyptr == *retname) ) + ++copyptr; + + /* and finally ... + * we remove any residual, redundantly duplicated separators from the dirname, + * reterminate, and return it. + */ + + path = copyptr; + while( *path ) + { + if( ((*copyptr++ = *path) == '/') || (*path++ == '\\') ) + { + while( (*path == '/') || (*path == '\\') ) + ++path; + } + } + *copyptr = '\0'; + return retname; + } + + else if( (*retname == '/') || (*retname == '\\') ) + { + *copyptr++ = *retname; + *copyptr = '\0'; + return retfail; + } + } + } + + /* path is NULL, or an empty string; default return value is "." ... + * return this in our own static buffer, but strcpy it, just in case + * the caller trashed it after a previous call. + */ + + strcpy( copyptr, "." ); + return retfail; +} + +/* $RCSfile$: end of file */ |