/*- * Copyright (c) 1991 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. */ #ifndef lint static char sccsid[] = "@(#)cd.c 5.2 (Berkeley) 3/13/91"; #endif /* not lint */ /* * 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 "mystring.h" #include #include #include #ifdef __STDC__ STATIC int docd(char *, int, int); STATIC void updatepwd(char *); STATIC void getpwd(void); STATIC char *getcomponent(void); #else STATIC int docd(); STATIC void updatepwd(); STATIC void getpwd(); STATIC char *getcomponent(); #endif char *curdir; /* current working directory */ STATIC char *cdcomppath; #if UDIR || TILDE extern int didudir; /* set if /u/logname or ~logname expanded */ #endif int cdcmd(argc, argv) char **argv; { char *dest; char *path; char *p; struct stat statb; char *padvance(); int tohome= 0; nextopt(nullstr); if ((dest = *argptr) == NULL) { if ((dest = bltinlookup("HOME", 1)) == NULL) error("HOME not set"); tohome = 1; } if (*dest == '/' || (path = bltinlookup("CDPATH", 1)) == NULL) path = nullstr; while ((p = padvance(&path, dest)) != NULL) { if (stat(p, &statb) >= 0 && (statb.st_mode & S_IFMT) == S_IFDIR && docd(p, strcmp(p, dest), tohome) >= 0) return 0; } error("can't cd to %s", dest); } /* * Actually do the chdir. If the name refers to symbolic links, we * compute the actual directory name before doing the cd. In an * interactive shell, print the directory name if "print" is nonzero * or if the name refers to a symbolic link. We also print the name * if "/u/logname" was expanded in it, since this is similar to a * symbolic link. (The check for this breaks if the user gives the * cd command some additional, unused arguments.) */ #if SYMLINKS == 0 STATIC int docd(dest, print, tohome) char *dest; { #if UDIR || TILDE if (didudir) print = 1; #endif INTOFF; if (chdir(dest) < 0) { INTON; return -1; } updatepwd(dest); INTON; if (print && iflag) out1fmt("%s\n", stackblock()); return 0; } #else STATIC int docd(dest, print, tohome) char *dest; { register char *p; register char *q; char *symlink; char *component; struct stat statb; int first; int i; TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, tohome)); #if UDIR || TILDE if (didudir) print = 1; #endif top: cdcomppath = dest; 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) error("lstat %s failed", stackblock()); if ((statb.st_mode & S_IFMT) != S_IFLNK) continue; /* Hit a symbolic link. We have to start all over again. */ print = 1; STPUTC('\0', p); symlink = grabstackstr(p); i = (int)statb.st_size + 2; /* 2 for '/' and '\0' */ if (cdcomppath != NULL) i += strlen(cdcomppath); p = stalloc(i); if (readlink(symlink, p, (int)statb.st_size) < 0) { error("readlink %s failed", stackblock()); } if (cdcomppath != NULL) { p[(int)statb.st_size] = '/'; scopy(cdcomppath, p + (int)statb.st_size + 1); } else { p[(int)statb.st_size] = '\0'; } if (p[0] != '/') { /* relative path name */ char *r; q = r = symlink; while (*q) { if (*q++ == '/') r = q; } *r = '\0'; dest = stalloc(strlen(symlink) + strlen(p) + 1); scopy(symlink, dest); strcat(dest, p); } else { dest = p; } goto top; } STPUTC('\0', p); p = grabstackstr(p); INTOFF; /* The empty string is not a legal argument to chdir on a POSIX 1003.1 * system. */ if (p[0] != '\0' && chdir(p) < 0) { INTON; return -1; } updatepwd(p); INTON; if (print && !tohome && iflag) out1fmt("%s\n", p); return 0; } #endif /* SYMLINKS */ /* * Get the next component of the path name pointed to by cdcomppath. * This routine overwrites the string pointed to by cdcomppath. */ STATIC char * getcomponent() { register 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. */ void hashcd(); STATIC void updatepwd(dir) char *dir; { char *new; char *p; hashcd(); /* update command hash table */ 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); if (curdir) ckfree(curdir); curdir = savestr(stackblock()); } int pwdcmd(argc, argv) char **argv; { getpwd(); out1str(curdir); out1c('\n'); return 0; } /* * Run /bin/pwd to find out what the current directory is. We suppress * interrupts throughout most of this, but the user can still break out * of it by killing the pwd program. If we already know the current * directory, this routine returns immediately. */ #define MAXPWD 256 STATIC void getpwd() { char buf[MAXPWD]; char *p; int i; int status; struct job *jp; int pip[2]; if (curdir) return; INTOFF; if (pipe(pip) < 0) error("Pipe call failed"); jp = makejob((union node *)NULL, 1); if (forkshell(jp, (union node *)NULL, FORK_NOJOB) == 0) { close(pip[0]); if (pip[1] != 1) { close(1); copyfd(pip[1], 1); close(pip[1]); } execl("/bin/pwd", "pwd", (char *)0); error("Cannot exec /bin/pwd"); } 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; } 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; }