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-rw-r--r--usr/dash/redir.c459
1 files changed, 459 insertions, 0 deletions
diff --git a/usr/dash/redir.c b/usr/dash/redir.c
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index 0000000..f96a76b
--- /dev/null
+++ b/usr/dash/redir.c
@@ -0,0 +1,459 @@
+/*-
+ * 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/stat.h>
+#include <sys/types.h>
+#include <sys/param.h> /* PIPE_BUF */
+#include <signal.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+/*
+ * Code for dealing with input/output redirection.
+ */
+
+#include "main.h"
+#include "shell.h"
+#include "nodes.h"
+#include "jobs.h"
+#include "options.h"
+#include "expand.h"
+#include "redir.h"
+#include "output.h"
+#include "memalloc.h"
+#include "error.h"
+
+
+#define REALLY_CLOSED -3 /* fd that was closed and still is */
+#define EMPTY -2 /* marks an unused slot in redirtab */
+#define CLOSED -1 /* fd opened for redir needs to be closed */
+
+#ifndef PIPE_BUF
+# define PIPESIZE 4096 /* amount of buffering in a pipe */
+#else
+# define PIPESIZE PIPE_BUF
+#endif
+
+
+MKINIT
+struct redirtab {
+ struct redirtab *next;
+ int renamed[10];
+};
+
+
+MKINIT struct redirtab *redirlist;
+
+STATIC int openredirect(union node *);
+#ifdef notyet
+STATIC void dupredirect(union node *, int, char[10]);
+#else
+STATIC void dupredirect(union node *, int);
+#endif
+STATIC int openhere(union node *);
+
+
+/*
+ * Process a list of redirection commands. If the REDIR_PUSH flag is set,
+ * old file descriptors are stashed away so that the redirection can be
+ * undone by calling popredir. If the REDIR_BACKQ flag is set, then the
+ * standard output, and the standard error if it becomes a duplicate of
+ * stdout, is saved in memory.
+ */
+
+void
+redirect(union node *redir, int flags)
+{
+ union node *n;
+ struct redirtab *sv;
+ int i;
+ int fd;
+ int newfd;
+ int *p;
+#if notyet
+ char memory[10]; /* file descriptors to write to memory */
+
+ for (i = 10 ; --i >= 0 ; )
+ memory[i] = 0;
+ memory[1] = flags & REDIR_BACKQ;
+#endif
+ if (!redir)
+ return;
+ sv = NULL;
+ INTOFF;
+ if (likely(flags & REDIR_PUSH))
+ sv = redirlist;
+ n = redir;
+ do {
+ newfd = openredirect(n);
+ if (newfd < -1)
+ continue;
+
+ fd = n->nfile.fd;
+
+ if (sv) {
+ p = &sv->renamed[fd];
+ i = *p;
+
+ if (likely(i == EMPTY)) {
+ i = CLOSED;
+ if (fd != newfd) {
+ i = savefd(fd, fd);
+ fd = -1;
+ }
+ }
+
+ if (i == newfd)
+ /* Can only happen if i == newfd == CLOSED */
+ i = REALLY_CLOSED;
+
+ *p = i;
+ }
+
+ if (fd == newfd)
+ continue;
+
+#ifdef notyet
+ dupredirect(n, newfd, memory);
+#else
+ dupredirect(n, newfd);
+#endif
+ } while ((n = n->nfile.next));
+ INTON;
+#ifdef notyet
+ if (memory[1])
+ out1 = &memout;
+ if (memory[2])
+ out2 = &memout;
+#endif
+ if (flags & REDIR_SAVEFD2 && sv->renamed[2] >= 0)
+ preverrout.fd = sv->renamed[2];
+}
+
+
+STATIC int
+openredirect(union node *redir)
+{
+ struct stat64 sb;
+ char *fname;
+ int f;
+
+ switch (redir->nfile.type) {
+ case NFROM:
+ fname = redir->nfile.expfname;
+ if ((f = open64(fname, O_RDONLY)) < 0)
+ goto eopen;
+ break;
+ case NFROMTO:
+ fname = redir->nfile.expfname;
+ if ((f = open64(fname, O_RDWR|O_CREAT, 0666)) < 0)
+ goto ecreate;
+ break;
+ case NTO:
+ /* Take care of noclobber mode. */
+ if (Cflag) {
+ fname = redir->nfile.expfname;
+ if (stat64(fname, &sb) < 0) {
+ if ((f = open64(fname, O_WRONLY|O_CREAT|O_EXCL, 0666)) < 0)
+ goto ecreate;
+ } else if (!S_ISREG(sb.st_mode)) {
+ if ((f = open64(fname, O_WRONLY, 0666)) < 0)
+ goto ecreate;
+ if (fstat64(f, &sb) < 0 && S_ISREG(sb.st_mode)) {
+ close(f);
+ errno = EEXIST;
+ goto ecreate;
+ }
+ } else {
+ errno = EEXIST;
+ goto ecreate;
+ }
+ break;
+ }
+ /* FALLTHROUGH */
+ case NCLOBBER:
+ fname = redir->nfile.expfname;
+ if ((f = open64(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) < 0)
+ goto ecreate;
+ break;
+ case NAPPEND:
+ fname = redir->nfile.expfname;
+ if ((f = open64(fname, O_WRONLY|O_CREAT|O_APPEND, 0666)) < 0)
+ goto ecreate;
+ break;
+ case NTOFD:
+ case NFROMFD:
+ f = redir->ndup.dupfd;
+ if (f == redir->nfile.fd)
+ f = -2;
+ break;
+ default:
+#ifdef DEBUG
+ abort();
+#endif
+ /* Fall through to eliminate warning. */
+ case NHERE:
+ case NXHERE:
+ f = openhere(redir);
+ break;
+ }
+
+ return f;
+ecreate:
+ sh_error("cannot create %s: %s", fname, errmsg(errno, E_CREAT));
+eopen:
+ sh_error("cannot open %s: %s", fname, errmsg(errno, E_OPEN));
+}
+
+
+STATIC void
+#ifdef notyet
+dupredirect(redir, f, memory)
+#else
+dupredirect(redir, f)
+#endif
+ union node *redir;
+ int f;
+#ifdef notyet
+ char memory[10];
+#endif
+ {
+ int fd = redir->nfile.fd;
+ int err = 0;
+
+#ifdef notyet
+ memory[fd] = 0;
+#endif
+ if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) {
+ /* if not ">&-" */
+ if (f >= 0) {
+#ifdef notyet
+ if (memory[f])
+ memory[fd] = 1;
+ else
+#endif
+ if (dup2(f, fd) < 0) {
+ err = errno;
+ goto err;
+ }
+ return;
+ }
+ f = fd;
+ } else if (dup2(f, fd) < 0)
+ err = errno;
+
+ close(f);
+ if (err < 0)
+ goto err;
+
+ return;
+
+err:
+ sh_error("%d: %s", f, strerror(err));
+}
+
+
+/*
+ * Handle here documents. Normally we fork off a process to write the
+ * data to a pipe. If the document is short, we can stuff the data in
+ * the pipe without forking.
+ */
+
+STATIC int
+openhere(union node *redir)
+{
+ char *p;
+ int pip[2];
+ size_t len = 0;
+
+ if (pipe(pip) < 0)
+ sh_error("Pipe call failed");
+
+ p = redir->nhere.doc->narg.text;
+ if (redir->type == NXHERE) {
+ expandarg(redir->nhere.doc, NULL, EXP_QUOTED);
+ p = stackblock();
+ }
+
+ len = strlen(p);
+ if (len <= PIPESIZE) {
+ xwrite(pip[1], p, len);
+ goto out;
+ }
+
+ if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) {
+ close(pip[0]);
+ signal(SIGINT, SIG_IGN);
+ signal(SIGQUIT, SIG_IGN);
+ signal(SIGHUP, SIG_IGN);
+#ifdef SIGTSTP
+ signal(SIGTSTP, SIG_IGN);
+#endif
+ signal(SIGPIPE, SIG_DFL);
+ xwrite(pip[1], p, len);
+ _exit(0);
+ }
+out:
+ close(pip[1]);
+ return pip[0];
+}
+
+
+
+/*
+ * Undo the effects of the last redirection.
+ */
+
+void
+popredir(int drop)
+{
+ struct redirtab *rp;
+ int i;
+
+ INTOFF;
+ rp = redirlist;
+ for (i = 0 ; i < 10 ; i++) {
+ switch (rp->renamed[i]) {
+ case CLOSED:
+ if (!drop)
+ close(i);
+ break;
+ case EMPTY:
+ case REALLY_CLOSED:
+ break;
+ default:
+ if (!drop)
+ dup2(rp->renamed[i], i);
+ close(rp->renamed[i]);
+ break;
+ }
+ }
+ redirlist = rp->next;
+ ckfree(rp);
+ INTON;
+}
+
+/*
+ * Undo all redirections. Called on error or interrupt.
+ */
+
+#ifdef mkinit
+
+INCLUDE "redir.h"
+
+RESET {
+ /*
+ * Discard all saved file descriptors.
+ */
+ unwindredir(0);
+}
+
+#endif
+
+
+
+/*
+ * Move a file descriptor to > 10. Invokes sh_error on error unless
+ * the original file dscriptor is not open.
+ */
+
+int
+savefd(int from, int ofd)
+{
+ int newfd;
+ int err;
+
+ newfd = fcntl(from, F_DUPFD, 10);
+ err = newfd < 0 ? errno : 0;
+ if (err != EBADF) {
+ close(ofd);
+ if (err)
+ sh_error("%d: %s", from, strerror(err));
+ else
+ fcntl(newfd, F_SETFD, FD_CLOEXEC);
+ }
+
+ return newfd;
+}
+
+
+int
+redirectsafe(union node *redir, int flags)
+{
+ int err;
+ volatile int saveint;
+ struct jmploc *volatile savehandler = handler;
+ struct jmploc jmploc;
+
+ SAVEINT(saveint);
+ if (!(err = setjmp(jmploc.loc) * 2)) {
+ handler = &jmploc;
+ redirect(redir, flags);
+ }
+ handler = savehandler;
+ if (err && exception != EXERROR)
+ longjmp(handler->loc, 1);
+ RESTOREINT(saveint);
+ return err;
+}
+
+
+void unwindredir(struct redirtab *stop)
+{
+ while (redirlist != stop)
+ popredir(0);
+}
+
+
+struct redirtab *pushredir(union node *redir)
+{
+ struct redirtab *sv;
+ struct redirtab *q;
+ int i;
+
+ q = redirlist;
+ if (!redir)
+ goto out;
+
+ sv = ckmalloc(sizeof (struct redirtab));
+ sv->next = q;
+ redirlist = sv;
+ for (i = 0; i < 10; i++)
+ sv->renamed[i] = EMPTY;
+
+out:
+ return q;
+}
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