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mirror of https://git.FreeBSD.org/src.git synced 2024-12-20 11:11:24 +00:00
freebsd/usr.sbin/sup/lib/path.c
Peter Wemm d14071a4b3 Import the unmodified version of the sup that we are using.
The heritage of this version is not clear.  It appears to be NetBSD
derived from some time ago.
1995-12-26 04:54:48 +00:00

97 lines
3.3 KiB
C

/*
* Copyright (c) 1991 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the rights
* to redistribute these changes.
*/
/* path -- break filename into directory and file
*
* path (filename,direc,file);
* char *filename,*direc,*file;
* filename is input; direc and file are output (user-supplied).
* file will not have any trailing /; direc might.
*
* Note these rules:
* 1. trailing / are ignored (except as first character)
* 2. x/y is x;y where y contains no / (x may contain /)
* 3. /y is /;y where y contains no /
* 4. y is .;y where y contains no /
* 5. is .;. (null filename)
* 6. / is /;. (the root directory)
*
* Algorithm is this:
* 1. delete trailing / except in first position
* 2. if any /, find last one; change to null; y++
* else y = x; (x is direc; y is file)
* 3. if y is null, y = .
* 4. if x equals y, x = .
* else if x is null, x = /
*
* HISTORY
* 20-Nov-79 Steven Shafer (sas) at Carnegie-Mellon University
* Copied verbatim from PDP-11. Still as messy as ever.
* Some people have asked for a modification (I think that's a better
* idea than a new routine) which will change the directory name
* into an absolute pathname if it isn't one already. The change
* involves doing a getwd() and prepending that if appropriate, with
* a "/" in between that and the directory part of the path.
* If you want to be cute, you can also resolve ".."s at that time.
*
*/
path (original,direc,file)
char *original,*direc,*file;
{
register char *y;
/* x is direc */
register char *p;
/* copy and note the end */
p = original;
y = direc;
while (*y++ = *p++) ; /* copy string */
/* y now points to first char after null */
--y; /* y now points to null */
--y; /* y now points to last char of string before null */
/* chop off trailing / except as first character */
while (y>direc && *y == '/') --y; /* backpedal past / */
/* y now points to char before first trailing / or null */
*(++y) = 0; /* chop off end of string */
/* y now points to null */
/* find last /, if any. If found, change to null and bump y */
while (y>direc && *y != '/') --y;
/* y now points to / or direc. Note *direc may be / */
if (*y == '/') {
*y++ = 0;
}
/* find file name part */
if (*y) strcpy (file,y);
else strcpy (file,".");
/* find directory part */
if (direc == y) strcpy (direc,".");
else if (*direc == 0) strcpy (direc,"/");
/* else direc already has proper value */
}