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Diffstat (limited to 'usr/dash/cd.c')
| -rw-r--r-- | usr/dash/cd.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/usr/dash/cd.c b/usr/dash/cd.c new file mode 100644 index 0000000..89c6c30 --- /dev/null +++ b/usr/dash/cd.c @@ -0,0 +1,313 @@ +/*- + * Copyright (c) 1991, 1993 + * The Regents of the University of California. All rights reserved. + * Copyright (c) 1997-2005 + * Herbert Xu <herbert@gondor.apana.org.au>. 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. + */ + +#include <sys/types.h> +#include <sys/stat.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <limits.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 "main.h" +#include "mystring.h" +#include "show.h" +#include "cd.h" + +#define CD_PHYSICAL 1 +#define CD_PRINT 2 + +STATIC int docd(const char *, int); +STATIC const char *updatepwd(const char *); +STATIC char *getpwd(void); +STATIC int cdopt(void); + +STATIC char *curdir = nullstr; /* current working directory */ +STATIC char *physdir = nullstr; /* physical working directory */ + +STATIC int +cdopt() +{ + int flags = 0; + int i, j; + + j = 'L'; + while ((i = nextopt("LP"))) { + if (i != j) { + flags ^= CD_PHYSICAL; + j = i; + } + } + + return flags; +} + +int +cdcmd(int argc, char **argv) +{ + const char *dest; + const char *path; + const char *p; + char c; + struct stat statb; + int flags; + + flags = cdopt(); + dest = *argptr; + if (!dest) + dest = bltinlookup(homestr); + else if (dest[0] == '-' && dest[1] == '\0') { + dest = bltinlookup("OLDPWD"); + flags |= CD_PRINT; + } + if (!dest) + dest = nullstr; + if (*dest == '/') + goto step6; + if (*dest == '.') { + c = dest[1]; +dotdot: + switch (c) { + case '\0': + case '/': + goto step6; + case '.': + c = dest[2]; + if (c != '.') + goto dotdot; + } + } + if (!*dest) + dest = "."; + path = bltinlookup("CDPATH"); + while (path) { + c = *path; + p = padvance(&path, dest); + if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) { + if (c && c != ':') + flags |= CD_PRINT; +docd: + if (!docd(p, flags)) + goto out; + goto err; + } + } + +step6: + p = dest; + goto docd; + +err: + sh_error("can't cd to %s", dest); + /* NOTREACHED */ +out: + if (flags & CD_PRINT) + out1fmt(snlfmt, curdir); + return 0; +} + + +/* + * Actually do the chdir. We also call hashcd to let the routines in exec.c + * know that the current directory has changed. + */ + +STATIC int +docd(const char *dest, int flags) +{ + const char *dir = 0; + int err; + + TRACE(("docd(\"%s\", %d) called\n", dest, flags)); + + INTOFF; + if (!(flags & CD_PHYSICAL)) { + dir = updatepwd(dest); + if (dir) + dest = dir; + } + err = chdir(dest); + if (err) + goto out; + setpwd(dir, 1); + hashcd(); +out: + INTON; + return err; +} + + +/* + * Update curdir (the name of the current directory) in response to a + * cd command. + */ + +STATIC const char * +updatepwd(const char *dir) +{ + char *new; + char *p; + char *cdcomppath; + const char *lim; + + cdcomppath = sstrdup(dir); + STARTSTACKSTR(new); + if (*dir != '/') { + if (curdir == nullstr) + return 0; + new = stputs(curdir, new); + } + new = makestrspace(strlen(dir) + 2, new); + lim = stackblock() + 1; + if (*dir != '/') { + if (new[-1] != '/') + USTPUTC('/', new); + if (new > lim && *lim == '/') + lim++; + } else { + USTPUTC('/', new); + cdcomppath++; + if (dir[1] == '/' && dir[2] != '/') { + USTPUTC('/', new); + cdcomppath++; + lim++; + } + } + p = strtok(cdcomppath, "/"); + while (p) { + switch(*p) { + case '.': + if (p[1] == '.' && p[2] == '\0') { + while (new > lim) { + STUNPUTC(new); + if (new[-1] == '/') + break; + } + break; + } else if (p[1] == '\0') + break; + /* fall through */ + default: + new = stputs(p, new); + USTPUTC('/', new); + } + p = strtok(0, "/"); + } + if (new > lim) + STUNPUTC(new); + *new = 0; + return stackblock(); +} + + +/* + * Find out what the current directory is. If we already know the current + * directory, this routine returns immediately. + */ +inline +STATIC char * +getpwd() +{ +#ifdef __GLIBC__ + char *dir = getcwd(0, 0); + if (dir) + return dir; +#else + char buf[PATH_MAX]; + if(getcwd(buf, sizeof(buf))) + return savestr(buf); +#endif + sh_warnx("getcwd() failed: %s", strerror(errno)); + return nullstr; +} + +int +pwdcmd(int argc, char **argv) +{ + int flags; + const char *dir = curdir; + + flags = cdopt(); + if (flags) { + if (physdir == nullstr) + setpwd(dir, 0); + dir = physdir; + } + out1fmt(snlfmt, dir); + return 0; +} + +void +setpwd(const char *val, int setold) +{ + char *oldcur, *dir; + + oldcur = dir = curdir; + + if (setold) { + setvar("OLDPWD", oldcur, VEXPORT); + } + INTOFF; + if (physdir != nullstr) { + if (physdir != oldcur) + free(physdir); + physdir = nullstr; + } + if (oldcur == val || !val) { + char *s = getpwd(); + physdir = s; + if (!val) + dir = s; + } else + dir = savestr(val); + if (oldcur != dir && oldcur != nullstr) { + free(oldcur); + } + curdir = dir; + INTON; + setvar("PWD", dir, VEXPORT); +} |