/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include "sh.h"#include "ksh_stat.h" /* *	Contains a routine to search a : separated list of *	paths (a la CDPATH) and make appropiate file names. *	Also contains a routine to simplify .'s and ..'s out of *	a path name. * *	Larry Bouzane (larry@cs.mun.ca) */ /* * $Log: path.c,v $ * Revision 1.2  1994/05/19  18:32:40  michael * Merge complete, stdio replaced, various fixes. (pre autoconf) * * Revision 1.1  1994/04/06  13:14:03  michael * Initial revision * * Revision 4.2  1990/12/06  18:05:24  larry * Updated test code to reflect parameter change. * Fixed problem with /a/./.dir being simplified to /a and not /a/.dir due * to *(cur+2) == *f test instead of the correct cur+2 == f * * Revision 4.1  90/10/29  14:42:19  larry * base MUN version *  * Revision 3.1.0.4  89/02/16  20:28:36  larry * Forgot to set *pathlist to NULL when last changed make_path(). *  * Revision 3.1.0.3  89/02/13  20:29:55  larry * Fixed up cd so that it knew when a node from CDPATH was used and would * print a message only when really necessary. *  * Revision 3.1.0.2  89/02/13  17:51:22  larry * Merged with Eric Gisin's version. *  * Revision 3.1.0.1  89/02/13  17:50:58  larry * *** empty log message *** *  * Revision 3.1  89/02/13  17:49:28  larry * *** empty log message *** *  */ #ifdef S_ISLNKstatic char	*do_phys_path ARGS((XString *xsp, char *xp, const char *path));#endif /* S_ISLNK */ /* *	Makes a filename into result using the following algorithm. *	- make result NULL *	- if file starts with '/', append file to result & set cdpathp to NULL *	- if file starts with ./ or ../ append cwd and file to result *	  and set cdpathp to NULL *	- if the first element of cdpathp doesnt start with a '/' xx or '.' xx *	  then cwd is appended to result. *	- the first element of cdpathp is appended to result *	- file is appended to result *	- cdpathp is set to the start of the next element in cdpathp (or NULL *	  if there are no more elements. *	The return value indicates whether a non-null element from cdpathp *	was appened to result. */intmake_path(cwd, file, cdpathp, xsp, phys_pathp)	const char *cwd;	const char *file;	char	**cdpathp;	/* & of : separated list */	XString	*xsp;	int	*phys_pathp;{	int	rval = 0;	int	use_cdpath = 1;	char	*plist;	int	len;	int	plen = 0;	char	*xp = Xstring(*xsp, xp); 	if (!file)		file = null; 	if (!ISRELPATH(file)) {		*phys_pathp = 0;		use_cdpath = 0;	} else {		if (file[0] == '.') {			char c = file[1]; 			if (c == '.')				c = file[2];			if (ISDIRSEP(c) || c == '\0')				use_cdpath = 0;		} 		plist = *cdpathp;		if (!plist)			use_cdpath = 0;		else if (use_cdpath) {			char *pend; 			for (pend = plist; *pend && *pend != PATHSEP; pend++)				;			plen = pend - plist;			*cdpathp = *pend ? ++pend : (char *) 0;		} 		if ((use_cdpath == 0 || !plen || ISRELPATH(plist))		    && (cwd && *cwd))		{			len = strlen(cwd);			XcheckN(*xsp, xp, len);			memcpy(xp, cwd, len);			xp += len;			if (!ISDIRSEP(cwd[len - 1]))				Xput(*xsp, xp, DIRSEP);		}		*phys_pathp = Xlength(*xsp, xp);		if (use_cdpath && plen) {			XcheckN(*xsp, xp, plen);			memcpy(xp, plist, plen);			xp += plen;			if (!ISDIRSEP(plist[plen - 1]))				Xput(*xsp, xp, DIRSEP);			rval = 1;		}	} 	len = strlen(file) + 1;	XcheckN(*xsp, xp, len);	memcpy(xp, file, len); 	if (!use_cdpath)		*cdpathp = (char *) 0; 	return rval;} /* * Simplify pathnames containing "." and ".." entries. * ie, simplify_path("/a/b/c/./../d/..") returns "/a/b" */voidsimplify_path(path)	char	*path;{	char	*cur;	char	*t;	int	isrooted;	char	*very_start = path;	char	*start; 	if (!*path)		return; 	if ((isrooted = ISROOTEDPATH(path)))		very_start++;#if defined (OS2) || defined (__CYGWIN__)	if (path[0] && path[1] == ':')	/* skip a: */		very_start += 2;#endif /* OS2 || __CYGWIN__ */ 	/* Before			After	 *  /foo/			/foo	 *  /foo/../../bar		/bar	 *  /foo/./blah/..		/foo	 *  .				.	 *  ..				..	 *  ./foo			foo	 *  foo/../../../bar		../../bar	 * OS2 and CYGWIN:	 *  a:/foo/../..		a:/	 *  a:.				a:	 *  a:..			a:..	 *  a:foo/../../blah		a:../blah	 */ #ifdef __CYGWIN__       /* preserve leading double-slash on pathnames (for UNC paths) */       if (path[0] && ISDIRSEP(path[0]) && path[1] && ISDIRSEP(path[1]))               very_start++;#endif /* __CYGWIN__ */ 	for (cur = t = start = very_start; ; ) {		/* treat multiple '/'s as one '/' */		while (ISDIRSEP(*t))			t++; 		if (*t == '\0') {			if (cur == path)				/* convert empty path to dot */				*cur++ = '.';			*cur = '\0';			break;		} 		if (t[0] == '.') {			if (!t[1] || ISDIRSEP(t[1])) {				t += 1;				continue;			} else if (t[1] == '.' && (!t[2] || ISDIRSEP(t[2]))) {				if (!isrooted && cur == start) {					if (cur != very_start)						*cur++ = DIRSEP;					*cur++ = '.';					*cur++ = '.';					start = cur;				} else if (cur != start)					while (--cur > start && !ISDIRSEP(*cur))						;				t += 2;				continue;			}		} 		if (cur != very_start)			*cur++ = DIRSEP; 		/* find/copy next component of pathname */		while (*t && !ISDIRSEP(*t))			*cur++ = *t++;	}}  voidset_current_wd(path)	char *path;{	int len;	char *p = path; 	if (!p && !(p = ksh_get_wd((char *) 0, 0)))		p = null; 	len = strlen(p) + 1; 	if (len > current_wd_size)		current_wd = aresize(current_wd, current_wd_size = len, APERM);	memcpy(current_wd, p, len);	if (p != path && p != null)		afree(p, ATEMP);} #ifdef S_ISLNKchar *get_phys_path(path)	const char *path;{	XString xs;	char *xp; 	Xinit(xs, xp, strlen(path) + 1, ATEMP); 	xp = do_phys_path(&xs, xp, path); 	if (!xp)		return (char *) 0; 	if (Xlength(xs, xp) == 0)		Xput(xs, xp, DIRSEP);	Xput(xs, xp, '\0'); 	return Xclose(xs, xp);} static char *do_phys_path(xsp, xp, path)	XString *xsp;	char *xp;	const char *path;{	const char *p, *q;	int len, llen;	int savepos;	char lbuf[PATH]; 	Xcheck(*xsp, xp);	for (p = path; p; p = q) {		while (ISDIRSEP(*p))			p++;		if (!*p)			break;		len = (q = ksh_strchr_dirsep(p)) ? q - p : strlen(p);		if (len == 1 && p[0] == '.')			continue;		if (len == 2 && p[0] == '.' && p[1] == '.') {			while (xp > Xstring(*xsp, xp)) {				xp--;				if (ISDIRSEP(*xp))					break;			}			continue;		} 		savepos = Xsavepos(*xsp, xp);		Xput(*xsp, xp, DIRSEP);		XcheckN(*xsp, xp, len + 1);		memcpy(xp, p, len);		xp += len;		*xp = '\0'; 		llen = readlink(Xstring(*xsp, xp), lbuf, sizeof(lbuf) - 1);		if (llen < 0) {			/* EINVAL means it wasn't a symlink... */			if (errno != EINVAL)				return (char *) 0;			continue;		}		lbuf[llen] = '\0'; 		/* If absolute path, start from scratch.. */		xp = ISABSPATH(lbuf) ? Xstring(*xsp, xp)				     : Xrestpos(*xsp, xp, savepos);		if (!(xp = do_phys_path(xsp, xp, lbuf)))			return (char *) 0;	}	return xp;}#endif /* S_ISLNK */ #ifdef	TEST main(argc, argv){	int	rv;	char	*cp, cdpath[256], pwd[256], file[256], result[256]; 	printf("enter CDPATH: "); gets(cdpath);	printf("enter PWD: "); gets(pwd);	while (1) {		if (printf("Enter file: "), gets(file) == 0)			return 0;		cp = cdpath;		do {			rv = make_path(pwd, file, &cp, result, sizeof(result));			printf("make_path returns (%d), \"%s\" ", rv, result);			simplify_path(result);			printf("(simpifies to \"%s\")\n", result);		} while (cp);	}}#endif	/* TEST */