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dir.c revision 1.17
      1 /* $NetBSD: dir.c,v 1.17 2001/09/14 14:03:59 wiz Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 1980, 1991, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 #if 0
     39 static char sccsid[] = "@(#)dir.c	8.1 (Berkeley) 5/31/93";
     40 #else
     41 __RCSID("$NetBSD: dir.c,v 1.17 2001/09/14 14:03:59 wiz Exp $");
     42 #endif
     43 #endif /* not lint */
     44 
     45 #include <sys/param.h>
     46 #include <sys/stat.h>
     47 
     48 #include <errno.h>
     49 #include <stdlib.h>
     50 #include <string.h>
     51 #include <unistd.h>
     52 
     53 #if __STDC__
     54 # include <stdarg.h>
     55 #else
     56 # include <varargs.h>
     57 #endif
     58 
     59 #include "csh.h"
     60 #include "dir.h"
     61 #include "extern.h"
     62 
     63 /* Directory management. */
     64 
     65 static struct directory *dfind(Char *);
     66 static Char *dfollow(Char *);
     67 static void printdirs(void);
     68 static Char *dgoto(Char *);
     69 static void skipargs(Char ***, char *);
     70 static void dnewcwd(struct directory *);
     71 static void dset(Char *);
     72 
     73 struct directory dhead;		/* "head" of loop */
     74 int printd;			/* force name to be printed */
     75 
     76 static int dirflag = 0;
     77 
     78 /*
     79  * dinit - initialize current working directory
     80  */
     81 void
     82 dinit(Char *hp)
     83 {
     84     static const char emsg[] = "csh: Trying to start from \"%s\"\n";
     85     char path[MAXPATHLEN];
     86     struct directory *dp;
     87     const char *ecp;
     88     Char *cp;
     89 
     90     /* Don't believe the login shell home, because it may be a symlink */
     91     ecp = getcwd(path, MAXPATHLEN);
     92     if (ecp == NULL || *ecp == '\0') {
     93 	(void)fprintf(csherr, "csh: %s\n", strerror(errno));
     94 	if (hp && *hp) {
     95 	    ecp = short2str(hp);
     96 	    if (chdir(ecp) == -1)
     97 		cp = NULL;
     98 	    else
     99 		cp = hp;
    100 	    (void)fprintf(csherr, emsg, vis_str(hp));
    101 	}
    102 	else
    103 	    cp = NULL;
    104 	if (cp == NULL) {
    105 	    (void)fprintf(csherr, emsg, "/");
    106 	    if (chdir("/") == -1) {
    107 		/* I am not even try to print an error message! */
    108 		xexit(1);
    109 	    }
    110 	    cp = SAVE("/");
    111 	}
    112     }
    113     else {
    114 	struct stat swd, shp;
    115 
    116 	/*
    117 	 * See if $HOME is the working directory we got and use that
    118 	 */
    119 	if (hp && *hp &&
    120 	    stat(ecp, &swd) != -1 && stat(short2str(hp), &shp) != -1 &&
    121 	    swd.st_dev == shp.st_dev && swd.st_ino == shp.st_ino)
    122 	    cp = hp;
    123 	else {
    124 	    const char *cwd;
    125 
    126 	    /*
    127 	     * use PWD if we have it (for subshells)
    128 	     */
    129 	    if ((cwd = getenv("PWD")) != NULL) {
    130 		if (stat(cwd, &shp) != -1 && swd.st_dev == shp.st_dev &&
    131 		    swd.st_ino == shp.st_ino)
    132 		    ecp = cwd;
    133 	    }
    134 	    cp = dcanon(SAVE(ecp), STRNULL);
    135 	}
    136     }
    137 
    138     dp = (struct directory *)xcalloc(sizeof(struct directory), 1);
    139     dp->di_name = Strsave(cp);
    140     dp->di_count = 0;
    141     dhead.di_next = dhead.di_prev = dp;
    142     dp->di_next = dp->di_prev = &dhead;
    143     printd = 0;
    144     dnewcwd(dp);
    145 }
    146 
    147 static void
    148 dset(Char *dp)
    149 {
    150     Char **vec;
    151 
    152     /*
    153      * Don't call set() directly cause if the directory contains ` or
    154      * other junk characters glob will fail.
    155      */
    156 
    157     vec = (Char **)xmalloc((size_t)(2 * sizeof(Char **)));
    158     vec[0] = Strsave(dp);
    159     vec[1] = 0;
    160     setq(STRcwd, vec, &shvhed);
    161     Setenv(STRPWD, dp);
    162 }
    163 
    164 #define DIR_LONG 1
    165 #define DIR_VERT 2
    166 #define DIR_LINE 4
    167 
    168 static void
    169 skipargs(Char ***v, char *str)
    170 {
    171     Char  **n, *s;
    172 
    173     n = *v;
    174     dirflag = 0;
    175     for (n++; *n != NULL && (*n)[0] == '-'; n++)
    176 	for (s = &((*n)[1]); *s; s++)
    177 	    switch (*s) {
    178 	    case 'l':
    179 		dirflag |= DIR_LONG;
    180 		break;
    181 	    case 'n':
    182 		dirflag |= DIR_LINE;
    183 		break;
    184 	    case 'v':
    185 		dirflag |= DIR_VERT;
    186 		break;
    187 	    default:
    188 		stderror(ERR_DIRUS, vis_str(**v), str);
    189 		/* NOTREACHED */
    190 	    }
    191     *v = n;
    192 }
    193 
    194 /*
    195  * dodirs - list all directories in directory loop
    196  */
    197 void
    198 /*ARGSUSED*/
    199 dodirs(Char **v, struct command *t)
    200 {
    201     skipargs(&v, "");
    202 
    203     if (*v != NULL)
    204 	stderror(ERR_DIRUS, "dirs", "");
    205     printdirs();
    206 }
    207 
    208 static void
    209 printdirs(void)
    210 {
    211     struct directory *dp;
    212     Char *hp, *s;
    213     int cur, idx, len;
    214 
    215     hp = value(STRhome);
    216     if (*hp == '\0')
    217 	hp = NULL;
    218     dp = dcwd;
    219     idx = 0;
    220     cur = 0;
    221     do {
    222 	if (dp == &dhead)
    223 	    continue;
    224 	if (dirflag & DIR_VERT) {
    225 	    (void)fprintf(cshout, "%d\t", idx++);
    226 	    cur = 0;
    227 	}
    228 	if (!(dirflag & DIR_LONG) && hp != NULL && !eq(hp, STRslash) &&
    229 	    (len = Strlen(hp), Strncmp(hp, dp->di_name, len) == 0) &&
    230 	    (dp->di_name[len] == '\0' || dp->di_name[len] == '/'))
    231 	    len = Strlen(s = (dp->di_name + len)) + 2;
    232 	else
    233 	    len = Strlen(s = dp->di_name) + 1;
    234 
    235 	cur += len;
    236 	if ((dirflag & DIR_LINE) && cur >= 80 - 1 && len < 80) {
    237 	    (void)fprintf(cshout, "\n");
    238 	    cur = len;
    239 	}
    240 	(void) fprintf(cshout, "%s%s%c", (s != dp->di_name)? "~" : "",
    241 	    vis_str(s), (dirflag & DIR_VERT) ? '\n' : ' ');
    242     } while ((dp = dp->di_prev) != dcwd);
    243     if (!(dirflag & DIR_VERT))
    244 	(void)fprintf(cshout, "\n");
    245 }
    246 
    247 void
    248 dtildepr(Char *home, Char *dir)
    249 {
    250     if (!eq(home, STRslash) && prefix(home, dir))
    251 	(void)fprintf(cshout, "~%s", vis_str(dir + Strlen(home)));
    252     else
    253 	(void)fprintf(cshout, "%s", vis_str(dir));
    254 }
    255 
    256 void
    257 dtilde(void)
    258 {
    259     struct directory *d;
    260 
    261     d = dcwd;
    262     do {
    263 	if (d == &dhead)
    264 	    continue;
    265 	d->di_name = dcanon(d->di_name, STRNULL);
    266     } while ((d = d->di_prev) != dcwd);
    267 
    268     dset(dcwd->di_name);
    269 }
    270 
    271 
    272 /* dnormalize():
    273  *	If the name starts with . or .. then we might need to normalize
    274  *	it depending on the symbolic link flags
    275  */
    276 Char *
    277 dnormalize(Char *cp)
    278 {
    279 #define UC (unsigned char)
    280 #define ISDOT(c) (UC(c)[0] == '.' && ((UC(c)[1] == '\0') || (UC(c)[1] == '/')))
    281 #define ISDOTDOT(c) (UC(c)[0] == '.' && ISDOT(&((c)[1])))
    282     if ((unsigned char) cp[0] == '/')
    283 	return (Strsave(cp));
    284 
    285     if (adrof(STRignore_symlinks)) {
    286 	int     dotdot = 0;
    287 	Char   *dp, *cwd;
    288 
    289 	cwd = (Char *)xmalloc((size_t)((Strlen(dcwd->di_name) + 3) *
    290 	    sizeof(Char)));
    291 	(void)Strcpy(cwd, dcwd->di_name);
    292 
    293 	/*
    294 	 * Ignore . and count ..'s
    295 	 */
    296 	while (*cp) {
    297 	    if (ISDOT(cp)) {
    298 		if (*++cp)
    299 		    cp++;
    300 	    }
    301 	    else if (ISDOTDOT(cp)) {
    302 		dotdot++;
    303 		cp += 2;
    304 		if (*cp)
    305 		    cp++;
    306 	    }
    307 	    else
    308 		break;
    309 	}
    310 	while (dotdot > 0) {
    311 	    dp = Strrchr(cwd, '/');
    312 	    if (dp) {
    313 		*dp = '\0';
    314 		dotdot--;
    315 	    }
    316 	    else
    317 		break;
    318 	}
    319 
    320 	if (*cp) {
    321 	    cwd[dotdot = Strlen(cwd)] = '/';
    322 	    cwd[dotdot + 1] = '\0';
    323 	    dp = Strspl(cwd, cp);
    324 	    xfree((ptr_t) cwd);
    325 	    return dp;
    326 	}
    327 	else {
    328 	    if (!*cwd) {
    329 		cwd[0] = '/';
    330 		cwd[1] = '\0';
    331 	    }
    332 	    return cwd;
    333 	}
    334     }
    335     return Strsave(cp);
    336 }
    337 
    338 /*
    339  * dochngd - implement chdir command.
    340  */
    341 void
    342 /*ARGSUSED*/
    343 dochngd(Char **v, struct command *t)
    344 {
    345     struct directory *dp;
    346     Char *cp;
    347 
    348     skipargs(&v, " [<dir>]");
    349     printd = 0;
    350     if (*v == NULL) {
    351 	if ((cp = value(STRhome)) == NULL || *cp == 0)
    352 	    stderror(ERR_NAME | ERR_NOHOMEDIR);
    353 	if (chdir(short2str(cp)) < 0)
    354 	    stderror(ERR_NAME | ERR_CANTCHANGE);
    355 	cp = Strsave(cp);
    356     }
    357     else if (v[1] != NULL)
    358 	stderror(ERR_NAME | ERR_TOOMANY);
    359     else if ((dp = dfind(*v)) != 0) {
    360 	char   *tmp;
    361 
    362 	printd = 1;
    363 	if (chdir(tmp = short2str(dp->di_name)) < 0)
    364 	    stderror(ERR_SYSTEM, tmp, strerror(errno));
    365 	dcwd->di_prev->di_next = dcwd->di_next;
    366 	dcwd->di_next->di_prev = dcwd->di_prev;
    367 	dfree(dcwd);
    368 	dnewcwd(dp);
    369 	return;
    370     }
    371     else
    372 	cp = dfollow(*v);
    373     dp = (struct directory *)xcalloc(sizeof(struct directory), 1);
    374     dp->di_name = cp;
    375     dp->di_count = 0;
    376     dp->di_next = dcwd->di_next;
    377     dp->di_prev = dcwd->di_prev;
    378     dp->di_prev->di_next = dp;
    379     dp->di_next->di_prev = dp;
    380     dfree(dcwd);
    381     dnewcwd(dp);
    382 }
    383 
    384 static Char *
    385 dgoto(Char *cp)
    386 {
    387     Char *dp;
    388 
    389     if (*cp != '/') {
    390 	Char *p, *q;
    391 	int cwdlen;
    392 
    393 	for (p = dcwd->di_name; *p++;)
    394 	    continue;
    395 	if ((cwdlen = p - dcwd->di_name - 1) == 1)	/* root */
    396 	    cwdlen = 0;
    397 	for (p = cp; *p++;)
    398 	    continue;
    399 	dp = (Char *)xmalloc((size_t)((cwdlen + (p - cp) + 1) * sizeof(Char)));
    400 	for (p = dp, q = dcwd->di_name; (*p++ = *q++) != '\0';)
    401 	    continue;
    402 	if (cwdlen)
    403 	    p[-1] = '/';
    404 	else
    405 	    p--;		/* don't add a / after root */
    406 	for (q = cp; (*p++ = *q++) != '\0';)
    407 	    continue;
    408 	xfree((ptr_t) cp);
    409 	cp = dp;
    410 	dp += cwdlen;
    411     }
    412     else
    413 	dp = cp;
    414 
    415     cp = dcanon(cp, dp);
    416     return cp;
    417 }
    418 
    419 /*
    420  * dfollow - change to arg directory; fall back on cdpath if not valid
    421  */
    422 static Char *
    423 dfollow(Char *cp)
    424 {
    425     char ebuf[MAXPATHLEN];
    426     struct varent *c;
    427     Char *dp;
    428     int serrno;
    429 
    430     cp = globone(cp, G_ERROR);
    431     /*
    432      * if we are ignoring symlinks, try to fix relatives now.
    433      */
    434     dp = dnormalize(cp);
    435     if (chdir(short2str(dp)) >= 0) {
    436 	xfree((ptr_t) cp);
    437 	return dgoto(dp);
    438     }
    439     else {
    440 	xfree((ptr_t) dp);
    441 	if (chdir(short2str(cp)) >= 0)
    442 	    return dgoto(cp);
    443 	serrno = errno;
    444     }
    445 
    446     if (cp[0] != '/' && !prefix(STRdotsl, cp) && !prefix(STRdotdotsl, cp)
    447 	&& (c = adrof(STRcdpath))) {
    448 	Char  **cdp;
    449 	Char *p;
    450 	Char    buf[MAXPATHLEN];
    451 
    452 	for (cdp = c->vec; *cdp; cdp++) {
    453 	    for (dp = buf, p = *cdp; (*dp++ = *p++) != '\0';)
    454 		continue;
    455 	    dp[-1] = '/';
    456 	    for (p = cp; (*dp++ = *p++) != '\0';)
    457 		continue;
    458 	    if (chdir(short2str(buf)) >= 0) {
    459 		printd = 1;
    460 		xfree((ptr_t) cp);
    461 		cp = Strsave(buf);
    462 		return dgoto(cp);
    463 	    }
    464 	}
    465     }
    466     dp = value(cp);
    467     if ((dp[0] == '/' || dp[0] == '.') && chdir(short2str(dp)) >= 0) {
    468 	xfree((ptr_t) cp);
    469 	cp = Strsave(dp);
    470 	printd = 1;
    471 	return dgoto(cp);
    472     }
    473     (void)strcpy(ebuf, short2str(cp));
    474     xfree((ptr_t) cp);
    475     stderror(ERR_SYSTEM, ebuf, strerror(serrno));
    476     /* NOTREACHED */
    477 }
    478 
    479 /*
    480  * dopushd - push new directory onto directory stack.
    481  *	with no arguments exchange top and second.
    482  *	with numeric argument (+n) bring it to top.
    483  */
    484 void
    485 /*ARGSUSED*/
    486 dopushd(Char **v, struct command *t)
    487 {
    488     struct directory *dp;
    489 
    490     skipargs(&v, " [<dir>|+<n>]");
    491     printd = 1;
    492     if (*v == NULL) {
    493 	char   *tmp;
    494 
    495 	if ((dp = dcwd->di_prev) == &dhead)
    496 	    dp = dhead.di_prev;
    497 	if (dp == dcwd)
    498 	    stderror(ERR_NAME | ERR_NODIR);
    499 	if (chdir(tmp = short2str(dp->di_name)) < 0)
    500 	    stderror(ERR_SYSTEM, tmp, strerror(errno));
    501 	dp->di_prev->di_next = dp->di_next;
    502 	dp->di_next->di_prev = dp->di_prev;
    503 	dp->di_next = dcwd->di_next;
    504 	dp->di_prev = dcwd;
    505 	dcwd->di_next->di_prev = dp;
    506 	dcwd->di_next = dp;
    507     }
    508     else if (v[1] != NULL)
    509 	stderror(ERR_NAME | ERR_TOOMANY);
    510     else if ((dp = dfind(*v)) != NULL) {
    511 	char   *tmp;
    512 
    513 	if (chdir(tmp = short2str(dp->di_name)) < 0)
    514 	    stderror(ERR_SYSTEM, tmp, strerror(errno));
    515     }
    516     else {
    517 	Char *ccp;
    518 
    519 	ccp = dfollow(*v);
    520 	dp = (struct directory *)xcalloc(sizeof(struct directory), 1);
    521 	dp->di_name = ccp;
    522 	dp->di_count = 0;
    523 	dp->di_prev = dcwd;
    524 	dp->di_next = dcwd->di_next;
    525 	dcwd->di_next = dp;
    526 	dp->di_next->di_prev = dp;
    527     }
    528     dnewcwd(dp);
    529 }
    530 
    531 /*
    532  * dfind - find a directory if specified by numeric (+n) argument
    533  */
    534 static struct directory *
    535 dfind(Char *cp)
    536 {
    537     struct directory *dp;
    538     Char *ep;
    539     int i;
    540 
    541     if (*cp++ != '+')
    542 	return (0);
    543     for (ep = cp; Isdigit(*ep); ep++)
    544 	continue;
    545     if (*ep)
    546 	return (0);
    547     i = getn(cp);
    548     if (i <= 0)
    549 	return (0);
    550     for (dp = dcwd; i != 0; i--) {
    551 	if ((dp = dp->di_prev) == &dhead)
    552 	    dp = dp->di_prev;
    553 	if (dp == dcwd)
    554 	    stderror(ERR_NAME | ERR_DEEP);
    555     }
    556     return (dp);
    557 }
    558 
    559 /*
    560  * dopopd - pop a directory out of the directory stack
    561  *	with a numeric argument just discard it.
    562  */
    563 void
    564 /*ARGSUSED*/
    565 dopopd(Char **v, struct command *t)
    566 {
    567     struct directory *dp, *p = NULL;
    568 
    569     skipargs(&v, " [+<n>]");
    570     printd = 1;
    571     if (*v == NULL)
    572 	dp = dcwd;
    573     else if (v[1] != NULL)
    574 	stderror(ERR_NAME | ERR_TOOMANY);
    575     else if ((dp = dfind(*v)) == 0)
    576 	stderror(ERR_NAME | ERR_BADDIR);
    577     if (dp->di_prev == &dhead && dp->di_next == &dhead)
    578 	stderror(ERR_NAME | ERR_EMPTY);
    579     if (dp == dcwd) {
    580 	char *tmp;
    581 
    582 	if ((p = dp->di_prev) == &dhead)
    583 	    p = dhead.di_prev;
    584 	if (chdir(tmp = short2str(p->di_name)) < 0)
    585 	    stderror(ERR_SYSTEM, tmp, strerror(errno));
    586     }
    587     dp->di_prev->di_next = dp->di_next;
    588     dp->di_next->di_prev = dp->di_prev;
    589     if (dp == dcwd)
    590 	dnewcwd(p);
    591     else {
    592 	printdirs();
    593     }
    594     dfree(dp);
    595 }
    596 
    597 /*
    598  * dfree - free the directory (or keep it if it still has ref count)
    599  */
    600 void
    601 dfree(struct directory *dp)
    602 {
    603 
    604     if (dp->di_count != 0) {
    605 	dp->di_next = dp->di_prev = 0;
    606     }
    607     else {
    608 	xfree((char *) dp->di_name);
    609 	xfree((ptr_t) dp);
    610     }
    611 }
    612 
    613 /*
    614  * dcanon - canonicalize the pathname, removing excess ./ and ../ etc.
    615  *	we are of course assuming that the file system is standardly
    616  *	constructed (always have ..'s, directories have links)
    617  */
    618 Char *
    619 dcanon(Char *cp, Char *p)
    620 {
    621     Char link[MAXPATHLEN];
    622     char tlink[MAXPATHLEN];
    623     Char *newcp, *sp;
    624     Char *p1, *p2;	/* general purpose */
    625     int cc;
    626     bool slash;
    627 
    628     /*
    629      * christos: if the path given does not start with a slash prepend cwd. If
    630      * cwd does not start with a path or the result would be too long abort().
    631      */
    632     if (*cp != '/') {
    633 	Char tmpdir[MAXPATHLEN];
    634 
    635 	p1 = value(STRcwd);
    636 	if (p1 == NULL || *p1 != '/')
    637 	    abort();
    638 	if (Strlen(p1) + Strlen(cp) + 1 >= MAXPATHLEN)
    639 	    abort();
    640 	(void)Strcpy(tmpdir, p1);
    641 	(void)Strcat(tmpdir, STRslash);
    642 	(void)Strcat(tmpdir, cp);
    643 	xfree((ptr_t) cp);
    644 	cp = p = Strsave(tmpdir);
    645     }
    646 
    647     while (*p) {		/* for each component */
    648 	sp = p;			/* save slash address */
    649 	while (*++p == '/')	/* flush extra slashes */
    650 	    continue;
    651 	if (p != ++sp)
    652 	    for (p1 = sp, p2 = p; (*p1++ = *p2++) != '\0';)
    653 		continue;
    654 	p = sp;			/* save start of component */
    655 	slash = 0;
    656 	while (*++p)		/* find next slash or end of path */
    657 	    if (*p == '/') {
    658 		slash = 1;
    659 		*p = 0;
    660 		break;
    661 	    }
    662 
    663 	if (*sp == '\0') {	/* if component is null */
    664 	    if (--sp == cp)	/* if path is one char (i.e. /) */
    665 		break;
    666 	    else
    667 		*sp = '\0';
    668 	} else if (sp[0] == '.' && sp[1] == 0) {
    669 	    if (slash) {
    670 		for (p1 = sp, p2 = p + 1; (*p1++ = *p2++) != '\0';)
    671 		    continue;
    672 		p = --sp;
    673 	    }
    674 	    else if (--sp != cp)
    675 		*sp = '\0';
    676 	}
    677 	else if (sp[0] == '.' && sp[1] == '.' && sp[2] == 0) {
    678 	    /*
    679 	     * We have something like "yyy/xxx/..", where "yyy" can be null or
    680 	     * a path starting at /, and "xxx" is a single component. Before
    681 	     * compressing "xxx/..", we want to expand "yyy/xxx", if it is a
    682 	     * symbolic link.
    683 	     */
    684 	    *--sp = 0;		/* form the pathname for readlink */
    685 	    if (sp != cp && !adrof(STRignore_symlinks) &&
    686 		(cc = readlink(short2str(cp), tlink,
    687 			       sizeof tlink)) >= 0) {
    688 		(void)Strcpy(link, str2short(tlink));
    689 		link[cc] = '\0';
    690 
    691 		if (slash)
    692 		    *p = '/';
    693 		/*
    694 		 * Point p to the '/' in "/..", and restore the '/'.
    695 		 */
    696 		*(p = sp) = '/';
    697 		/*
    698 		 * find length of p
    699 		 */
    700 		for (p1 = p; *p1++;)
    701 		    continue;
    702 		if (*link != '/') {
    703 		    /*
    704 		     * Relative path, expand it between the "yyy/" and the
    705 		     * "/..". First, back sp up to the character past "yyy/".
    706 		     */
    707 		    while (*--sp != '/')
    708 			continue;
    709 		    sp++;
    710 		    *sp = 0;
    711 		    /*
    712 		     * New length is "yyy/" + link + "/.." and rest
    713 		     */
    714 		    p1 = newcp = (Char *)xmalloc(
    715 		        (size_t)(((sp - cp) + cc + (p1 - p)) * sizeof(Char)));
    716 		    /*
    717 		     * Copy new path into newcp
    718 		     */
    719 		    for (p2 = cp; (*p1++ = *p2++) != '\0';)
    720 			continue;
    721 		    for (p1--, p2 = link; (*p1++ = *p2++) != '\0';)
    722 			continue;
    723 		    for (p1--, p2 = p; (*p1++ = *p2++) != '\0';)
    724 			continue;
    725 		    /*
    726 		     * Restart canonicalization at expanded "/xxx".
    727 		     */
    728 		    p = sp - cp - 1 + newcp;
    729 		}
    730 		else {
    731 		    /*
    732 		     * New length is link + "/.." and rest
    733 		     */
    734 		    p1 = newcp = (Char *)xmalloc(
    735 		        (size_t)((cc + (p1 - p)) * sizeof(Char)));
    736 		    /*
    737 		     * Copy new path into newcp
    738 		     */
    739 		    for (p2 = link; (*p1++ = *p2++) != '\0';)
    740 			continue;
    741 		    for (p1--, p2 = p; (*p1++ = *p2++) != '\0';)
    742 			continue;
    743 		    /*
    744 		     * Restart canonicalization at beginning
    745 		     */
    746 		    p = newcp;
    747 		}
    748 		xfree((ptr_t) cp);
    749 		cp = newcp;
    750 		continue;	/* canonicalize the link */
    751 	    }
    752 	    *sp = '/';
    753 	    if (sp != cp)
    754 		while (*--sp != '/')
    755 		    continue;
    756 	    if (slash) {
    757 		for (p1 = sp + 1, p2 = p + 1; (*p1++ = *p2++) != '\0';)
    758 		    continue;
    759 		p = sp;
    760 	    }
    761 	    else if (cp == sp)
    762 		*++sp = '\0';
    763 	    else
    764 		*sp = '\0';
    765 	}
    766 	else {			/* normal dir name (not . or .. or nothing) */
    767 
    768 	    if (sp != cp && adrof(STRchase_symlinks) &&
    769 		!adrof(STRignore_symlinks) &&
    770 		(cc = readlink(short2str(cp), tlink, sizeof(tlink))) >= 0) {
    771 		(void)Strcpy(link, str2short(tlink));
    772 		link[cc] = '\0';
    773 
    774 		/*
    775 		 * restore the '/'.
    776 		 */
    777 		if (slash)
    778 		    *p = '/';
    779 
    780 		/*
    781 		 * point sp to p (rather than backing up).
    782 		 */
    783 		sp = p;
    784 
    785 		/*
    786 		 * find length of p
    787 		 */
    788 		for (p1 = p; *p1++;)
    789 		    continue;
    790 		if (*link != '/') {
    791 		    /*
    792 		     * Relative path, expand it between the "yyy/" and the
    793 		     * remainder. First, back sp up to the character past
    794 		     * "yyy/".
    795 		     */
    796 		    while (*--sp != '/')
    797 			continue;
    798 		    sp++;
    799 		    *sp = 0;
    800 		    /*
    801 		     * New length is "yyy/" + link + "/.." and rest
    802 		     */
    803 		    p1 = newcp = (Char *)xmalloc(
    804 		        (size_t)(((sp - cp) + cc + (p1 - p)) * sizeof(Char)));
    805 		    /*
    806 		     * Copy new path into newcp
    807 		     */
    808 		    for (p2 = cp; (*p1++ = *p2++) != '\0';)
    809 			continue;
    810 		    for (p1--, p2 = link; (*p1++ = *p2++) != '\0';)
    811 			continue;
    812 		    for (p1--, p2 = p; (*p1++ = *p2++) != '\0';)
    813 			continue;
    814 		    /*
    815 		     * Restart canonicalization at expanded "/xxx".
    816 		     */
    817 		    p = sp - cp - 1 + newcp;
    818 		}
    819 		else {
    820 		    /*
    821 		     * New length is link + the rest
    822 		     */
    823 		    p1 = newcp = (Char *)xmalloc(
    824 		        (size_t)((cc + (p1 - p)) * sizeof(Char)));
    825 		    /*
    826 		     * Copy new path into newcp
    827 		     */
    828 		    for (p2 = link; (*p1++ = *p2++) != '\0';)
    829 			continue;
    830 		    for (p1--, p2 = p; (*p1++ = *p2++) != '\0';)
    831 			continue;
    832 		    /*
    833 		     * Restart canonicalization at beginning
    834 		     */
    835 		    p = newcp;
    836 		}
    837 		xfree((ptr_t) cp);
    838 		cp = newcp;
    839 		continue;	/* canonicalize the link */
    840 	    }
    841 	    if (slash)
    842 		*p = '/';
    843 	}
    844     }
    845 
    846     /*
    847      * fix home...
    848      */
    849     p1 = value(STRhome);
    850     cc = Strlen(p1);
    851     /*
    852      * See if we're not in a subdir of STRhome
    853      */
    854     if (p1 && *p1 == '/' &&
    855 	(Strncmp(p1, cp, cc) != 0 || (cp[cc] != '/' && cp[cc] != '\0'))) {
    856 	static ino_t home_ino;
    857 	static dev_t home_dev = NODEV;
    858 	static Char *home_ptr = NULL;
    859 	struct stat statbuf;
    860 
    861 	/*
    862 	 * Get dev and ino of STRhome
    863 	 */
    864 	if (home_ptr != p1 &&
    865 	    stat(short2str(p1), &statbuf) != -1) {
    866 	    home_dev = statbuf.st_dev;
    867 	    home_ino = statbuf.st_ino;
    868 	    home_ptr = p1;
    869 	}
    870 	/*
    871 	 * Start comparing dev & ino backwards
    872 	 */
    873 	p2 = Strcpy(link, cp);
    874 	for (sp = NULL; *p2 && stat(short2str(p2), &statbuf) != -1;) {
    875 	    if (statbuf.st_dev == home_dev &&
    876 		statbuf.st_ino == home_ino) {
    877 		sp = (Char *) - 1;
    878 		break;
    879 	    }
    880 	    if ((sp = Strrchr(p2, '/')) != NULL)
    881 		*sp = '\0';
    882 	}
    883 	/*
    884 	 * See if we found it
    885 	 */
    886 	if (*p2 && sp == (Char *) -1) {
    887 	    /*
    888 	     * Use STRhome to make '~' work
    889 	     */
    890 	    newcp = Strspl(p1, cp + Strlen(p2));
    891 	    xfree((ptr_t) cp);
    892 	    cp = newcp;
    893 	}
    894     }
    895     return cp;
    896 }
    897 
    898 
    899 /*
    900  * dnewcwd - make a new directory in the loop the current one
    901  */
    902 static void
    903 dnewcwd(struct directory *dp)
    904 {
    905     dcwd = dp;
    906     dset(dcwd->di_name);
    907     if (printd && !(adrof(STRpushdsilent)))
    908 	printdirs();
    909 }
    910