/* $NetBSD: cd.c,v 1.23.2.1 1998/05/08 06:01:03 mycroft Exp $ */ /*- * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Kenneth Almquist. * * 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. */ #include #ifndef lint #if 0 static char sccsid[] = "@(#)cd.c 8.2 (Berkeley) 5/4/95"; #else __RCSID("$NetBSD: cd.c,v 1.23.2.1 1998/05/08 06:01:03 mycroft Exp $"); #endif #endif /* not lint */ #include #include #include #include #include #include /* * The cd and pwd commands. */ #include "shell.h" #include "var.h" #include "nodes.h" /* for jobs.h */ #include "jobs.h" #include "options.h" #include "output.h" #include "memalloc.h" #include "error.h" #include "exec.h" #include "redir.h" #include "mystring.h" #include "show.h" #include "cd.h" STATIC int docd __P((char *, int)); STATIC char *getcomponent __P((void)); STATIC void updatepwd __P((char *)); char *curdir = NULL; /* current working directory */ char *prevdir; /* previous working directory */ STATIC char *cdcomppath; int cdcmd(argc, argv) int argc; char **argv; { char *dest; char *path; char *p; struct stat statb; int print = 0; nextopt(nullstr); if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL) error("HOME not set"); if (*dest == '\0') dest = "."; if (dest[0] == '-' && dest[1] == '\0') { dest = prevdir ? prevdir : curdir; print = 1; if (dest) print = 1; else dest = "."; } if (*dest == '/' || (path = bltinlookup("CDPATH", 1)) == NULL) path = nullstr; while ((p = padvance(&path, dest)) != NULL) { if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) { if (!print) { /* * XXX - rethink */ if (p[0] == '.' && p[1] == '/' && p[2] != '\0') p += 2; print = strcmp(p, dest); } if (docd(p, print) >= 0) return 0; } } error("can't cd to %s", dest); /*NOTREACHED*/ return 0; } /* * Actually do the chdir. In an interactive shell, print the * directory name if "print" is nonzero. */ STATIC int docd(dest, print) char *dest; int print; { char *p; char *q; char *component; struct stat statb; int first; int badstat; TRACE(("docd(\"%s\", %d) called\n", dest, print)); /* * Check each component of the path. If we find a symlink or * something we can't stat, clear curdir to force a getcwd() * next time we get the value of the current directory. */ badstat = 0; cdcomppath = stalloc(strlen(dest) + 1); scopy(dest, cdcomppath); STARTSTACKSTR(p); if (*dest == '/') { STPUTC('/', p); cdcomppath++; } first = 1; while ((q = getcomponent()) != NULL) { if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) continue; if (! first) STPUTC('/', p); first = 0; component = q; while (*q) STPUTC(*q++, p); if (equal(component, "..")) continue; STACKSTRNUL(p); if ((lstat(stackblock(), &statb) < 0) || (S_ISLNK(statb.st_mode))) { /* print = 1; */ badstat = 1; break; } } INTOFF; if (chdir(dest) < 0) { INTON; return -1; } updatepwd(badstat ? NULL : dest); INTON; if (print && iflag && curdir) out1fmt("%s\n", curdir); return 0; } /* * Get the next component of the path name pointed to by cdcomppath. * This routine overwrites the string pointed to by cdcomppath. */ STATIC char * getcomponent() { char *p; char *start; if ((p = cdcomppath) == NULL) return NULL; start = cdcomppath; while (*p != '/' && *p != '\0') p++; if (*p == '\0') { cdcomppath = NULL; } else { *p++ = '\0'; cdcomppath = p; } return start; } /* * Update curdir (the name of the current directory) in response to a * cd command. We also call hashcd to let the routines in exec.c know * that the current directory has changed. */ STATIC void updatepwd(dir) char *dir; { char *new; char *p; hashcd(); /* update command hash table */ /* * If our argument is NULL, we don't know the current directory * any more because we traversed a symbolic link or something * we couldn't stat(). */ if (dir == NULL) { if (prevdir) ckfree(prevdir); INTOFF; prevdir = curdir; curdir = NULL; getpwd(); INTON; return; } cdcomppath = stalloc(strlen(dir) + 1); scopy(dir, cdcomppath); STARTSTACKSTR(new); if (*dir != '/') { if (curdir == NULL) return; p = curdir; while (*p) STPUTC(*p++, new); if (p[-1] == '/') STUNPUTC(new); } while ((p = getcomponent()) != NULL) { if (equal(p, "..")) { while (new > stackblock() && (STUNPUTC(new), *new) != '/'); } else if (*p != '\0' && ! equal(p, ".")) { STPUTC('/', new); while (*p) STPUTC(*p++, new); } } if (new == stackblock()) STPUTC('/', new); STACKSTRNUL(new); INTOFF; if (prevdir) ckfree(prevdir); prevdir = curdir; curdir = savestr(stackblock()); setvar("PWD", curdir, VEXPORT|VTEXTFIXED); INTON; } int pwdcmd(argc, argv) int argc; char **argv; { getpwd(); out1str(curdir); out1c('\n'); return 0; } #define MAXPWD 256 /* * Find out what the current directory is. If we already know the current * directory, this routine returns immediately. */ void getpwd() { char buf[MAXPWD]; if (curdir) return; /* * Things are a bit complicated here; we could have just used * getcwd, but traditionally getcwd is implemented using popen * to /bin/pwd. This creates a problem for us, since we cannot * keep track of the job if it is being ran behind our backs. * So we re-implement getcwd(), and we suppress interrupts * throughout the process. This is not completely safe, since * the user can still break out of it by killing the pwd program. * We still try to use getcwd for systems that we know have a * c implementation of getcwd, that does not open a pipe to * /bin/pwd. */ #if defined(__NetBSD__) || defined(__SVR4) if (getcwd(buf, sizeof(buf)) == NULL) { char *pwd = getenv("PWD"); struct stat stdot, stpwd; if (pwd && *pwd == '/' && stat(".", &stdot) != -1 && stat(pwd, &stpwd) != -1 && stdot.st_dev == stpwd.st_dev && stdot.st_ino == stpwd.st_ino) { curdir = savestr(pwd); return; } error("getcwd() failed: %s", strerror(errno)); } curdir = savestr(buf); #else { char *p; int i; int status; struct job *jp; int pip[2]; INTOFF; if (pipe(pip) < 0) error("Pipe call failed"); jp = makejob((union node *)NULL, 1); if (forkshell(jp, (union node *)NULL, FORK_NOJOB) == 0) { (void) close(pip[0]); if (pip[1] != 1) { close(1); copyfd(pip[1], 1); close(pip[1]); } (void) execl("/bin/pwd", "pwd", (char *)0); error("Cannot exec /bin/pwd"); } (void) close(pip[1]); pip[1] = -1; p = buf; while ((i = read(pip[0], p, buf + MAXPWD - p)) > 0 || (i == -1 && errno == EINTR)) { if (i > 0) p += i; } (void) close(pip[0]); pip[0] = -1; status = waitforjob(jp); if (status != 0) error((char *)0); if (i < 0 || p == buf || p[-1] != '\n') error("pwd command failed"); p[-1] = '\0'; } curdir = savestr(buf); INTON; #endif }