dir.c

早期freebsd实现

/*-
 * Copyright (c) 1980, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)dir.c	8.1 (Berkeley) 5/31/93";
#endif /* not lint */

#include <sys/param.h>
#include <sys/stat.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#if __STDC__
# include <stdarg.h>
#else
# include <varargs.h>
#endif

#include "csh.h"
#include "dir.h"
#include "extern.h"

/* Directory management. */

static struct directory
		*dfind __P((Char *));
static Char	*dfollow __P((Char *));
static void	 printdirs __P((void));
static Char	*dgoto __P((Char *));
static void	 dnewcwd __P((struct directory *));
static void	 dset __P((Char *));

struct directory dhead;		/* "head" of loop */
int     printd;			/* force name to be printed */

static int dirflag = 0;

/*
 * dinit - initialize current working directory
 */
void
dinit(hp)
    Char   *hp;
{
    register char *tcp;
    register Char *cp;
    register struct directory *dp;
    char    path[MAXPATHLEN];
    static char *emsg = "csh: Trying to start from \"%s\"\n";

    /* Don't believe the login shell home, because it may be a symlink */
    tcp = getwd(path);		/* see ngetwd.c for System V version */
    if (tcp == NULL || *tcp == '\0') {
	(void) fprintf(csherr, "csh: %s\n", path);
	if (hp && *hp) {
	    tcp = short2str(hp);
	    if (chdir(tcp) == -1)
		cp = NULL;
	    else
		cp = hp;
	    (void) fprintf(csherr, emsg, vis_str(hp));
	}
	else
	    cp = NULL;
	if (cp == NULL) {
	    (void) fprintf(csherr, emsg, "/");
	    if (chdir("/") == -1)
		/* I am not even try to print an error message! */
		xexit(1);
	    cp = SAVE("/");
	}
    }
    else {
	struct stat swd, shp;

	/*
	 * See if $HOME is the working directory we got and use that
	 */
	if (hp && *hp &&
	    stat(tcp, &swd) != -1 && stat(short2str(hp), &shp) != -1 &&
	    swd.st_dev == shp.st_dev && swd.st_ino == shp.st_ino)
	    cp = hp;
	else {
	    char   *cwd;

	    /*
	     * use PWD if we have it (for subshells)
	     */
	    if ((cwd = getenv("PWD")) != NULL) {
		if (stat(cwd, &shp) != -1 && swd.st_dev == shp.st_dev &&
		    swd.st_ino == shp.st_ino)
		    tcp = cwd;
	    }
	    cp = dcanon(SAVE(tcp), STRNULL);
	}
    }

    dp = (struct directory *) xcalloc(sizeof(struct directory), 1);
    dp->di_name = Strsave(cp);
    dp->di_count = 0;
    dhead.di_next = dhead.di_prev = dp;
    dp->di_next = dp->di_prev = &dhead;
    printd = 0;
    dnewcwd(dp);
}

static void
dset(dp)
Char *dp;
{
    /*
     * Don't call set() directly cause if the directory contains ` or
     * other junk characters glob will fail.
     */
    register Char **vec = (Char **) xmalloc((size_t) (2 * sizeof(Char **)));

    vec[0] = Strsave(dp);
    vec[1] = 0;
    setq(STRcwd, vec, &shvhed);
    Setenv(STRPWD, dp);
}

#define DIR_LONG 1
#define DIR_VERT 2
#define DIR_LINE 4

static void
skipargs(v, str)
    Char ***v;
    char   *str;
{
    Char  **n = *v, *s;

    dirflag = 0;
    for (n++; *n != NULL && (*n)[0] == '-'; n++)
	for (s = &((*n)[1]); *s; s++)
	    switch (*s) {
	    case 'l':
		dirflag |= DIR_LONG;
		break;
	    case 'v':
		dirflag |= DIR_VERT;
		break;
	    case 'n':
		dirflag |= DIR_LINE;
		break;
	    default:
		stderror(ERR_DIRUS, vis_str(**v), str);
		break;
	    }
    *v = n;
}

/*
 * dodirs - list all directories in directory loop
 */
void
/*ARGSUSED*/
dodirs(v, t)
    Char **v;
    struct command *t;
{
    skipargs(&v, "");

    if (*v != NULL)
	stderror(ERR_DIRUS, "dirs", "");
    printdirs();
}

static void
printdirs()
{
    register struct directory *dp;
    Char   *s, *hp = value(STRhome);
    int     idx, len, cur;

    if (*hp == '\0')
	hp = NULL;
    dp = dcwd;
    idx = 0;
    cur = 0;
    do {
	if (dp == &dhead)
	    continue;
	if (dirflag & DIR_VERT) {
	    (void) fprintf(cshout, "%d\t", idx++);
	    cur = 0;
	}
	if (!(dirflag & DIR_LONG) && hp != NULL && !eq(hp, STRslash) &&
	    (len = Strlen(hp), Strncmp(hp, dp->di_name, len) == 0) &&
	    (dp->di_name[len] == '\0' || dp->di_name[len] == '/')) 
	    len = Strlen(s = (dp->di_name + len)) + 2;
	else
	    len = Strlen(s = dp->di_name) + 1;

	cur += len;
	if ((dirflag & DIR_LINE) && cur >= 80 - 1 && len < 80) {
	    (void) fprintf(cshout, "\n");
	    cur = len;
	}
	(void) fprintf(cshout, s != dp->di_name ? "~%s%c" : "%s%c",
		vis_str(s), (dirflag & DIR_VERT) ? '\n' : ' ');
    } while ((dp = dp->di_prev) != dcwd);
    if (!(dirflag & DIR_VERT))
	(void) fprintf(cshout, "\n");
}

void
dtildepr(home, dir)
    register Char *home, *dir;
{

    if (!eq(home, STRslash) && prefix(home, dir))
	(void) fprintf(cshout, "~%s", vis_str(dir + Strlen(home)));
    else
	(void) fprintf(cshout, "%s", vis_str(dir));
}

void
dtilde()
{
    struct directory *d = dcwd;

    do {
	if (d == &dhead)
	    continue;
	d->di_name = dcanon(d->di_name, STRNULL);
    } while ((d = d->di_prev) != dcwd);

    dset(dcwd->di_name);
}


/* dnormalize():
 *	If the name starts with . or .. then we might need to normalize
 *	it depending on the symbolic link flags
 */
Char   *
dnormalize(cp)
    Char   *cp;
{

#define UC (unsigned char)
#define ISDOT(c) (UC(c)[0] == '.' && ((UC(c)[1] == '\0') || (UC(c)[1] == '/')))
#define ISDOTDOT(c) (UC(c)[0] == '.' && ISDOT(&((c)[1])))

    if ((unsigned char) cp[0] == '/')
	return (Strsave(cp));

    if (adrof(STRignore_symlinks)) {
	int     dotdot = 0;
	Char   *dp, *cwd;

	cwd = (Char *) xmalloc((size_t) ((Strlen(dcwd->di_name) + 3) *
					 sizeof(Char)));
	(void) Strcpy(cwd, dcwd->di_name);

	/*
	 * Ignore . and count ..'s
	 */
	while (*cp) {
	    if (ISDOT(cp)) {
		if (*++cp)
		    cp++;
	    }
	    else if (ISDOTDOT(cp)) {
		dotdot++;
		cp += 2;
		if (*cp)
		    cp++;
	    }
	    else
		break;
	}
	while (dotdot > 0)
	    if ((dp = Strrchr(cwd, '/'))) {
		*dp = '\0';
		dotdot--;
	    }
	    else
		break;

	if (*cp) {
	    cwd[dotdot = Strlen(cwd)] = '/';
	    cwd[dotdot + 1] = '\0';
	    dp = Strspl(cwd, cp);
	    xfree((ptr_t) cwd);
	    return dp;
	}
	else {
	    if (!*cwd) {
		cwd[0] = '/';
		cwd[1] = '\0';
	    }
	    return cwd;
	}
    }
    return Strsave(cp);
}

/*
 * dochngd - implement chdir command.
 */
void
/*ARGSUSED*/
dochngd(v, t)
    Char **v;
    struct command *t;
{
    register Char *cp;
    register struct directory *dp;

    skipargs(&v, " [<dir>]");
    printd = 0;
    if (*v == NULL) {
	if ((cp = value(STRhome)) == NULL || *cp == 0)
	    stderror(ERR_NAME | ERR_NOHOMEDIR);
	if (chdir(short2str(cp)) < 0)
	    stderror(ERR_NAME | ERR_CANTCHANGE);
	cp = Strsave(cp);
    }
    else if (v[1] != NULL) {
	stderror(ERR_NAME | ERR_TOOMANY);
	/* NOTREACHED */
	return;
    }
    else if ((dp = dfind(*v)) != 0) {
	char   *tmp;

	printd = 1;
	if (chdir(tmp = short2str(dp->di_name)) < 0)
	    stderror(ERR_SYSTEM, tmp, strerror(errno));
	dcwd->di_prev->di_next = dcwd->di_next;
	dcwd->di_next->di_prev = dcwd->di_prev;
	dfree(dcwd);
	dnewcwd(dp);
	return;
    }
    else
	cp = dfollow(*v);
    dp = (struct directory *) xcalloc(sizeof(struct directory), 1);
    dp->di_name = cp;
    dp->di_count = 0;
    dp->di_next = dcwd->di_next;
    dp->di_prev = dcwd->di_prev;
    dp->di_prev->di_next = dp;
    dp->di_next->di_prev = dp;
    dfree(dcwd);
    dnewcwd(dp);
}

static Char *
dgoto(cp)
    Char   *cp;
{
    Char   *dp;

    if (*cp != '/') {
	register Char *p, *q;
	int     cwdlen;

	for (p = dcwd->di_name; *p++;)
	    continue;
	if ((cwdlen = p - dcwd->di_name - 1) == 1)	/* root */
	    cwdlen = 0;
	for (p = cp; *p++;)
	    continue;
	dp = (Char *) xmalloc((size_t)((cwdlen + (p - cp) + 1) * sizeof(Char)));
	for (p = dp, q = dcwd->di_name; (*p++ = *q++) != '\0';)
	    continue;
	if (cwdlen)
	    p[-1] = '/';
	else
	    p--;		/* don't add a / after root */
	for (q = cp; (*p++ = *q++) != '\0';)
	    continue;
	xfree((ptr_t) cp);
	cp = dp;
	dp += cwdlen;
    }
    else
	dp = cp;

    cp = dcanon(cp, dp);
    return cp;
}

/*
 * dfollow - change to arg directory; fall back on cdpath if not valid
 */
static Char *
dfollow(cp)
    register Char *cp;
{
    register Char *dp;
    struct varent *c;
    char    ebuf[MAXPATHLEN];
    int serrno;

    cp = globone(cp, G_ERROR);
    /*
     * if we are ignoring symlinks, try to fix relatives now.
     */
    dp = dnormalize(cp);
    if (chdir(short2str(dp)) >= 0) {
	xfree((ptr_t) cp);
	return dgoto(dp);
    }
    else {
	xfree((ptr_t) dp);
	if (chdir(short2str(cp)) >= 0)
	    return dgoto(cp);
	serrno = errno;
    }

    if (cp[0] != '/' && !prefix(STRdotsl, cp) && !prefix(STRdotdotsl, cp)
	&& (c = adrof(STRcdpath))) {
	Char  **cdp;
	register Char *p;
	Char    buf[MAXPATHLEN];

	for (cdp = c->vec; *cdp; cdp++) {
	    for (dp = buf, p = *cdp; (*dp++ = *p++) != '\0';)
		continue;
	    dp[-1] = '/';
	    for (p = cp; (*dp++ = *p++) != '\0';)
		continue;
	    if (chdir(short2str(buf)) >= 0) {
		printd = 1;
		xfree((ptr_t) cp);
		cp = Strsave(buf);
		return dgoto(cp);
	    }
	}
    }