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Diffstat (limited to '')
-rw-r--r-- | src/kash/cd.c | 445 |
1 files changed, 445 insertions, 0 deletions
diff --git a/src/kash/cd.c b/src/kash/cd.c new file mode 100644 index 0000000..49fd157 --- /dev/null +++ b/src/kash/cd.c @@ -0,0 +1,445 @@ +/* $NetBSD: cd.c,v 1.34 2003/11/14 20:00:28 dsl 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. 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. + */ + +#if 0 +#ifndef lint +static char sccsid[] = "@(#)cd.c 8.2 (Berkeley) 5/4/95"; +#else +__RCSID("$NetBSD: cd.c,v 1.34 2003/11/14 20:00:28 dsl Exp $"); +#endif /* not lint */ +#endif + +#include <sys/types.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> + +/* + * 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" +#include "shinstance.h" + +STATIC int docd(shinstance *psh, char *, int); +STATIC char *getcomponent(shinstance *psh); +STATIC void updatepwd(shinstance *psh, char *); +STATIC void find_curdir(shinstance *psh, int noerror); + +/*char *curdir = NULL;*/ /* current working directory */ +/*char *prevdir;*/ /* previous working directory */ +/*STATIC char *cdcomppath;*/ + +int +cdcmd(shinstance *psh, int argc, char **argv) +{ + const char *dest; + const char *path; + char *p, *d; + struct stat statb; + int print = cdprint(psh); /* set -cdprint to enable */ + + nextopt(psh, nullstr); + + /* + * Try (quite hard) to have 'curdir' defined, nothing has set + * it on entry to the shell, but we want 'cd fred; cd -' to work. + */ + getpwd(psh, 1); + dest = *psh->argptr; + if (dest == NULL) { + dest = bltinlookup(psh, "HOME", 1); + if (dest == NULL) + error(psh, "HOME not set"); + } else { + if (psh->argptr[1]) { + /* Do 'ksh' style substitution */ + if (!psh->curdir) + error(psh, "PWD not set"); + p = strstr(psh->curdir, dest); + if (!p) + error(psh, "bad substitution"); + d = stalloc(psh, strlen(psh->curdir) + strlen(psh->argptr[1]) + 1); + memcpy(d, psh->curdir, p - psh->curdir); + strcpy(d + (p - psh->curdir), psh->argptr[1]); + strcat(d, p + strlen(dest)); + dest = d; + print = 1; + } + } + + if (dest[0] == '-' && dest[1] == '\0') { + dest = psh->prevdir ? psh->prevdir : psh->curdir; + print = 1; + } + if (*dest == '\0') + dest = "."; + if (IS_ROOT(dest) || (path = bltinlookup(psh, "CDPATH", 1)) == NULL) + path = nullstr; + while ((p = padvance(psh, &path, dest)) != NULL) { + if (shfile_stat(&psh->fdtab, 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(psh, p, print) >= 0) + return 0; + + } + } + error(psh, "can't cd to %s", dest); + /* NOTREACHED */ + return 1; +} + + +/* + * Actually do the chdir. In an interactive shell, print the + * directory name if "print" is nonzero. + */ + +STATIC int +docd(shinstance *psh, char *dest, int print) +{ + char *p; + char *q; + char *component; + struct stat statb; + int first; + int badstat; + + TRACE((psh, "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; + psh->cdcomppath = stalloc(psh, strlen(dest) + 1); + scopy(dest, psh->cdcomppath); + STARTSTACKSTR(psh, p); + if (IS_ROOT(dest)) { + STPUTC(psh, '/', p); + psh->cdcomppath++; + } + first = 1; + while ((q = getcomponent(psh)) != NULL) { + if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) + continue; + if (! first) + STPUTC(psh, '/', p); + first = 0; + component = q; + while (*q) + STPUTC(psh, *q++, p); + if (equal(component, "..")) + continue; + STACKSTRNUL(psh, p); + if ((shfile_lstat(&psh->fdtab, stackblock(psh), &statb) < 0) + || (S_ISLNK(statb.st_mode))) { + /* print = 1; */ + badstat = 1; + break; + } + } + + INTOFF; + if (shfile_chdir(&psh->fdtab, dest) < 0) { + INTON; + return -1; + } + updatepwd(psh, badstat ? NULL : dest); + INTON; + if (print && iflag(psh) && psh->curdir) + out1fmt(psh, "%s\n", psh->curdir); + return 0; +} + + +/* + * Get the next component of the path name pointed to by psh->cdcomppath. + * This routine overwrites the string pointed to by psh->cdcomppath. + */ + +STATIC char * +getcomponent(shinstance *psh) +{ + char *p; + char *start; + + if ((p = psh->cdcomppath) == NULL) + return NULL; + start = psh->cdcomppath; + while (*p != '/' && *p != '\0') + p++; + if (*p == '\0') { + psh->cdcomppath = NULL; + } else { + *p++ = '\0'; + psh->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(shinstance *psh, char *dir) +{ + char *new; + char *p; + + hashcd(psh); /* 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 || psh->curdir == NULL) { + if (psh->prevdir) + ckfree(psh, psh->prevdir); + INTOFF; + psh->prevdir = psh->curdir; + psh->curdir = NULL; + getpwd(psh, 1); + INTON; + if (psh->curdir) + setvar(psh, "PWD", psh->curdir, VEXPORT); + else + unsetvar(psh, "PWD", 0); + return; + } + psh->cdcomppath = stalloc(psh, strlen(dir) + 1); + scopy(dir, psh->cdcomppath); + STARTSTACKSTR(psh, new); + if (!IS_ROOT(dir)) { + p = psh->curdir; + while (*p) + STPUTC(psh, *p++, new); + if (p[-1] == '/') + STUNPUTC(psh, new); + } + while ((p = getcomponent(psh)) != NULL) { + if (equal(p, "..")) { + while (new > stackblock(psh) && (STUNPUTC(psh, new), *new) != '/'); + } else if (*p != '\0' && ! equal(p, ".")) { + STPUTC(psh, '/', new); + while (*p) + STPUTC(psh, *p++, new); + } + } + if (new == stackblock(psh)) + STPUTC(psh, '/', new); + STACKSTRNUL(psh, new); + INTOFF; + if (psh->prevdir) + ckfree(psh, psh->prevdir); + psh->prevdir = psh->curdir; + psh->curdir = savestr(psh, stackblock(psh)); + setvar(psh, "PWD", psh->curdir, VEXPORT); + INTON; +} + +/* + * Posix says the default should be 'pwd -L' (as below), however + * the 'cd' command (above) does something much nearer to the + * posix 'cd -P' (not the posix default of 'cd -L'). + * If 'cd' is changed to support -P/L then the default here + * needs to be revisited if the historic behaviour is to be kept. + */ + +int +pwdcmd(shinstance *psh, int argc, char **argv) +{ + int i; + char opt = 'L'; + + while ((i = nextopt(psh, "LP")) != '\0') + opt = i; + if (*psh->argptr) + error(psh, "unexpected argument"); + + if (opt == 'L') + getpwd(psh, 0); + else + find_curdir(psh, 0); + + setvar(psh, "PWD", psh->curdir, VEXPORT); + out1str(psh, psh->curdir); + out1c(psh, '\n'); + return 0; +} + + + + +#define MAXPWD 256 + +/* + * Find out what the current directory is. If we already know the current + * directory, this routine returns immediately. + */ +const char * +getpwd(shinstance *psh, int noerror) +{ + char *pwd; + struct stat stdot, stpwd; + /*static int first = 1;*/ + + if (psh->curdir) + return psh->curdir; + + if (psh->getpwd_first) { + psh->getpwd_first = 0; + pwd = sh_getenv(psh, "PWD"); + if (pwd && IS_ROOT(pwd) && shfile_stat(&psh->fdtab, ".", &stdot) != -1 && + shfile_stat(&psh->fdtab, pwd, &stpwd) != -1 && + stdot.st_dev == stpwd.st_dev && + stdot.st_ino == stpwd.st_ino) { + psh->curdir = savestr(psh, pwd); + return psh->curdir; + } + } + + find_curdir(psh, noerror); + + return psh->curdir; +} + +STATIC void +find_curdir(shinstance *psh, int noerror) +{ + int i; + char *pwd; + + /* + * 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 1 //defined(__NetBSD__) || defined(__SVR4) || defined(__INNOTEK_LIBC__) + + for (i = MAXPWD;; i *= 2) { + pwd = stalloc(psh, i); + if (shfile_getcwd(&psh->fdtab, pwd, i) != NULL) { + psh->curdir = savestr(psh, pwd); + return; + } + stunalloc(psh, pwd); + if (errno == ERANGE) + continue; + if (!noerror) + error(psh, "getcwd() failed: %s", sh_strerror(psh, errno)); + return; + } +#else + { + char *p; + int status; + struct job *jp; + int pip[2]; + + pwd = stalloc(psh, MAXPWD); + INTOFF; + if (pipe(pip) < 0) + error(psh, "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(psh, "Cannot exec /bin/pwd"); + } + (void) close(pip[1]); + pip[1] = -1; + p = pwd; + while ((i = read(pip[0], p, pwd + 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(psh, (char *)0); + if (i < 0 || p == pwd || p[-1] != '\n') { + if (noerror) { + INTON; + return; + } + error(psh, "pwd command failed"); + } + p[-1] = '\0'; + INTON; + psh->curdir = savestr(pwd); + return; + } +#endif +} |