1 files changed, 488 insertions, 0 deletions
diff --git a/src/redir.c b/src/redir.c
new file mode 100644
index 0000000..9bebcb6
--- /dev/null
+++ b/src/redir.c
@@ -0,0 +1,488 @@
+/*	$NetBSD: redir.c,v 1.27 2002/11/24 22:35:42 christos 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 <sys/cdefs.h>
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)redir.c	8.2 (Berkeley) 5/4/95";
+#else
+__RCSID("$NetBSD: redir.c,v 1.27 2002/11/24 22:35:42 christos Exp $");
+#endif
+#endif /* not lint */
+
+#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 EMPTY -2		/* marks an unused slot in redirtab */
+#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];
+	int nullredirs;
+};
+
+
+MKINIT struct redirtab *redirlist;
+MKINIT int nullredirs;
+
+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 *);
+STATIC int noclobberopen(const char *);
+
+
+/*
+ * 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
+	nullredirs++;
+	if (!redir) {
+		return;
+	}
+	sv = NULL;
+	INTOFF;
+	if (flags & REDIR_PUSH) {
+		struct redirtab *q;
+		q = ckmalloc(sizeof (struct redirtab));
+		q->next = redirlist;
+		redirlist = q;
+		q->nullredirs = nullredirs - 1;
+		for (i = 0 ; i < 10 ; i++)
+			q->renamed[i] = EMPTY;
+		nullredirs = 0;
+		sv = q;
+	}
+	n = redir;
+	do {
+		fd = n->nfile.fd;
+		if ((n->nfile.type == NTOFD || n->nfile.type == NFROMFD) &&
+		    n->ndup.dupfd == fd)
+			continue; /* redirect from/to same file descriptor */
+
+		newfd = openredirect(n);
+		if (fd == newfd)
+			continue;
+		if (sv && *(p = &sv->renamed[fd]) == EMPTY) {
+			int i = fcntl(fd, F_DUPFD, 10);
+			if (i == -1) {
+				i = errno;
+				if (i != EBADF) {
+					const char *m = strerror(i);
+					close(newfd);
+					error("%d: %s", fd, m);
+					/* NOTREACHED */
+				}
+			} else {
+				*p = i;
+				close(fd);
+			}
+		} else {
+			close(fd);
+		}
+#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 && sv->renamed[2] >= 0)
+		preverrout.fd = sv->renamed[2];
+}
+
+
+STATIC int
+openredirect(union node *redir)
+{
+	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|O_TRUNC, 0666)) < 0)
+			goto ecreate;
+		break;
+	case NTO:
+		/* Take care of noclobber mode. */
+		if (Cflag) {
+			fname = redir->nfile.expfname;
+			if ((f = noclobberopen(fname)) < 0)
+				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;
+	default:
+#ifdef DEBUG
+		abort();
+#endif
+		/* Fall through to eliminate warning. */
+	case NTOFD:
+	case NFROMFD:
+		f = -1;
+		break;
+	case NHERE:
+	case NXHERE:
+		f = openhere(redir);
+		break;
+	}
+
+	return f;
+ecreate:
+	error("cannot create %s: %s", fname, errmsg(errno, E_CREAT));
+eopen:
+	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;
+
+#ifdef notyet
+	memory[fd] = 0;
+#endif
+	if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) {
+		if (redir->ndup.dupfd >= 0) {	/* if not ">&-" */
+#ifdef notyet
+			if (memory[redir->ndup.dupfd])
+				memory[fd] = 1;
+			else
+#endif
+				copyfd(redir->ndup.dupfd, fd);
+		}
+		return;
+	}
+
+	if (f != fd) {
+		copyfd(f, fd);
+		close(f);
+	}
+	return;
+}
+
+
+/*
+ * 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)
+{
+	int pip[2];
+	size_t len = 0;
+
+	if (pipe(pip) < 0)
+		error("Pipe call failed");
+	if (redir->type == NHERE) {
+		len = strlen(redir->nhere.doc->narg.text);
+		if (len <= PIPESIZE) {
+			xwrite(pip[1], redir->nhere.doc->narg.text, 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);
+		if (redir->type == NHERE)
+			xwrite(pip[1], redir->nhere.doc->narg.text, len);
+		else
+			expandhere(redir->nhere.doc, pip[1]);
+		_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;
+
+	if (--nullredirs >= 0)
+		return;
+	INTOFF;
+	rp = redirlist;
+	for (i = 0 ; i < 10 ; i++) {
+		if (rp->renamed[i] != EMPTY) {
+			if (!drop) {
+				close(i);
+				copyfd(rp->renamed[i], i);
+			}
+			close(rp->renamed[i]);
+		}
+	}
+	redirlist = rp->next;
+	nullredirs = rp->nullredirs;
+	ckfree(rp);
+	INTON;
+}
+
+/*
+ * Undo all redirections.  Called on error or interrupt.
+ */
+
+#ifdef mkinit
+
+INCLUDE "redir.h"
+
+RESET {
+	clearredir(0);
+}
+
+#endif
+
+/*
+ * Discard all saved file descriptors.
+ */
+
+void
+clearredir(int drop)
+{
+	for (;;) {
+		nullredirs = 0;
+		if (!redirlist)
+			break;
+		popredir(drop);
+	}
+}
+
+
+
+/*
+ * Copy a file descriptor to be >= to.  Returns -1
+ * if the source file descriptor is closed, EMPTY if there are no unused
+ * file descriptors left.
+ */
+
+int
+copyfd(int from, int to)
+{
+	int newfd;
+
+	newfd = fcntl(from, F_DUPFD, to);
+	if (newfd < 0) {
+		int errno2 = errno;
+		if (errno2 == EMFILE)
+			return EMPTY;
+		else
+			error("%d: %s", from, strerror(errno2));
+	}
+	return newfd;
+}
+
+
+/*
+ * Open a file in noclobber mode.
+ * The code was copied from bash.
+ */
+int
+noclobberopen(fname)
+	const char *fname;
+{
+	int r, fd;
+	struct stat64 finfo, finfo2;
+
+	/*
+	 * If the file exists and is a regular file, return an error
+	 * immediately.
+	 */
+	r = stat64(fname, &finfo);
+	if (r == 0 && S_ISREG(finfo.st_mode)) {
+		errno = EEXIST;
+		return -1;
+	}
+
+	/*
+	 * If the file was not present (r != 0), make sure we open it
+	 * exclusively so that if it is created before we open it, our open
+	 * will fail.  Make sure that we do not truncate an existing file.
+	 * Note that we don't turn on O_EXCL unless the stat failed -- if the
+	 * file was not a regular file, we leave O_EXCL off.
+	 */
+	if (r != 0)
+		return open64(fname, O_WRONLY|O_CREAT|O_EXCL, 0666);
+	fd = open64(fname, O_WRONLY|O_CREAT, 0666);
+
+	/* If the open failed, return the file descriptor right away. */
+	if (fd < 0)
+		return fd;
+
+	/*
+	 * OK, the open succeeded, but the file may have been changed from a
+	 * non-regular file to a regular file between the stat and the open.
+	 * We are assuming that the O_EXCL open handles the case where FILENAME
+	 * did not exist and is symlinked to an existing file between the stat
+	 * and open.
+	 */
+
+	/*
+	 * If we can open it and fstat the file descriptor, and neither check
+	 * revealed that it was a regular file, and the file has not been
+	 * replaced, return the file descriptor.
+	 */
+	 if (fstat64(fd, &finfo2) == 0 && !S_ISREG(finfo2.st_mode) &&
+	     finfo.st_dev == finfo2.st_dev && finfo.st_ino == finfo2.st_ino)
+	 	return fd;
+
+	/* The file has been replaced.  badness. */
+	close(fd);
+	errno = EEXIST;
+	return -1;
+}
+
+
+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;
+}