auto import from //depot/cupcake/@135843
diff --git a/sh/error.c b/sh/error.c
new file mode 100644
index 0000000..8cbed19
--- /dev/null
+++ b/sh/error.c
@@ -0,0 +1,366 @@
+/* $NetBSD: error.c,v 1.31 2003/08/07 09:05:30 agc 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.
+ */
+
+#include <sys/cdefs.h>
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)error.c 8.2 (Berkeley) 5/4/95";
+#else
+__RCSID("$NetBSD: error.c,v 1.31 2003/08/07 09:05:30 agc Exp $");
+#endif
+#endif /* not lint */
+
+/*
+ * Errors and exceptions.
+ */
+
+#include <signal.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "shell.h"
+#include "main.h"
+#include "options.h"
+#include "output.h"
+#include "error.h"
+#include "show.h"
+
+#define signal bsd_signal
+/*
+ * Code to handle exceptions in C.
+ */
+
+struct jmploc *handler;
+int exception;
+volatile int suppressint;
+volatile int intpending;
+char *commandname;
+
+
+static void exverror(int, const char *, va_list)
+ __attribute__((__noreturn__));
+
+/*
+ * Called to raise an exception. Since C doesn't include exceptions, we
+ * just do a longjmp to the exception handler. The type of exception is
+ * stored in the global variable "exception".
+ */
+
+void
+exraise(int e)
+{
+ if (handler == NULL)
+ abort();
+ exception = e;
+ longjmp(handler->loc, 1);
+}
+
+
+/*
+ * Called from trap.c when a SIGINT is received. (If the user specifies
+ * that SIGINT is to be trapped or ignored using the trap builtin, then
+ * this routine is not called.) Suppressint is nonzero when interrupts
+ * are held using the INTOFF macro. The call to _exit is necessary because
+ * there is a short period after a fork before the signal handlers are
+ * set to the appropriate value for the child. (The test for iflag is
+ * just defensive programming.)
+ */
+
+void
+onint(void)
+{
+ sigset_t nsigset;
+
+ if (suppressint) {
+ intpending = 1;
+ return;
+ }
+ intpending = 0;
+ sigemptyset(&nsigset);
+ sigprocmask(SIG_SETMASK, &nsigset, NULL);
+ if (rootshell && iflag)
+ exraise(EXINT);
+ else {
+ signal(SIGINT, SIG_DFL);
+ raise(SIGINT);
+ }
+ /* NOTREACHED */
+}
+
+static void
+exvwarning(int sv_errno, const char *msg, va_list ap)
+{
+ /* Partially emulate line buffered output so that:
+ * printf '%d\n' 1 a 2
+ * and
+ * printf '%d %d %d\n' 1 a 2
+ * both generate sensible text when stdout and stderr are merged.
+ */
+ if (output.nextc != output.buf && output.nextc[-1] == '\n')
+ flushout(&output);
+ if (commandname)
+ outfmt(&errout, "%s: ", commandname);
+ if (msg != NULL) {
+ doformat(&errout, msg, ap);
+ if (sv_errno >= 0)
+ outfmt(&errout, ": ");
+ }
+ if (sv_errno >= 0)
+ outfmt(&errout, "%s", strerror(sv_errno));
+ out2c('\n');
+ flushout(&errout);
+}
+
+/*
+ * Exverror is called to raise the error exception. If the second argument
+ * is not NULL then error prints an error message using printf style
+ * formatting. It then raises the error exception.
+ */
+static void
+exverror(int cond, const char *msg, va_list ap)
+{
+ CLEAR_PENDING_INT;
+ INTOFF;
+
+#ifdef DEBUG
+ if (msg) {
+ TRACE(("exverror(%d, \"", cond));
+ TRACEV((msg, ap));
+ TRACE(("\") pid=%d\n", getpid()));
+ } else
+ TRACE(("exverror(%d, NULL) pid=%d\n", cond, getpid()));
+#endif
+ if (msg)
+ exvwarning(-1, msg, ap);
+
+ flushall();
+ exraise(cond);
+ /* NOTREACHED */
+}
+
+
+void
+error(const char *msg, ...)
+{
+ va_list ap;
+
+ va_start(ap, msg);
+ exverror(EXERROR, msg, ap);
+ /* NOTREACHED */
+ va_end(ap);
+}
+
+
+void
+exerror(int cond, const char *msg, ...)
+{
+ va_list ap;
+
+ va_start(ap, msg);
+ exverror(cond, msg, ap);
+ /* NOTREACHED */
+ va_end(ap);
+}
+
+/*
+ * error/warning routines for external builtins
+ */
+
+void
+sh_exit(int rval)
+{
+ exerrno = rval & 255;
+ exraise(EXEXEC);
+}
+
+void
+sh_err(int status, const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ exvwarning(errno, fmt, ap);
+ va_end(ap);
+ sh_exit(status);
+}
+
+void
+sh_verr(int status, const char *fmt, va_list ap)
+{
+ exvwarning(errno, fmt, ap);
+ sh_exit(status);
+}
+
+void
+sh_errx(int status, const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ exvwarning(-1, fmt, ap);
+ va_end(ap);
+ sh_exit(status);
+}
+
+void
+sh_verrx(int status, const char *fmt, va_list ap)
+{
+ exvwarning(-1, fmt, ap);
+ sh_exit(status);
+}
+
+void
+sh_warn(const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ exvwarning(errno, fmt, ap);
+ va_end(ap);
+}
+
+void
+sh_vwarn(const char *fmt, va_list ap)
+{
+ exvwarning(errno, fmt, ap);
+}
+
+void
+sh_warnx(const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ exvwarning(-1, fmt, ap);
+ va_end(ap);
+}
+
+void
+sh_vwarnx(const char *fmt, va_list ap)
+{
+ exvwarning(-1, fmt, ap);
+}
+
+
+/*
+ * Table of error messages.
+ */
+
+struct errname {
+ short errcode; /* error number */
+ short action; /* operation which encountered the error */
+ const char *msg; /* text describing the error */
+};
+
+
+#define ALL (E_OPEN|E_CREAT|E_EXEC)
+
+STATIC const struct errname errormsg[] = {
+ { EINTR, ALL, "interrupted" },
+ { EACCES, ALL, "permission denied" },
+ { EIO, ALL, "I/O error" },
+ { EEXIST, ALL, "file exists" },
+ { ENOENT, E_OPEN, "no such file" },
+ { ENOENT, E_CREAT,"directory nonexistent" },
+ { ENOENT, E_EXEC, "not found" },
+ { ENOTDIR, E_OPEN, "no such file" },
+ { ENOTDIR, E_CREAT,"directory nonexistent" },
+ { ENOTDIR, E_EXEC, "not found" },
+ { EISDIR, ALL, "is a directory" },
+#ifdef EMFILE
+ { EMFILE, ALL, "too many open files" },
+#endif
+ { ENFILE, ALL, "file table overflow" },
+ { ENOSPC, ALL, "file system full" },
+#ifdef EDQUOT
+ { EDQUOT, ALL, "disk quota exceeded" },
+#endif
+#ifdef ENOSR
+ { ENOSR, ALL, "no streams resources" },
+#endif
+ { ENXIO, ALL, "no such device or address" },
+ { EROFS, ALL, "read-only file system" },
+ { ETXTBSY, ALL, "text busy" },
+#ifdef EAGAIN
+ { EAGAIN, E_EXEC, "not enough memory" },
+#endif
+ { ENOMEM, ALL, "not enough memory" },
+#ifdef ENOLINK
+ { ENOLINK, ALL, "remote access failed" },
+#endif
+#ifdef EMULTIHOP
+ { EMULTIHOP, ALL, "remote access failed" },
+#endif
+#ifdef ECOMM
+ { ECOMM, ALL, "remote access failed" },
+#endif
+#ifdef ESTALE
+ { ESTALE, ALL, "remote access failed" },
+#endif
+#ifdef ETIMEDOUT
+ { ETIMEDOUT, ALL, "remote access failed" },
+#endif
+#ifdef ELOOP
+ { ELOOP, ALL, "symbolic link loop" },
+#endif
+ { E2BIG, E_EXEC, "argument list too long" },
+#ifdef ELIBACC
+ { ELIBACC, E_EXEC, "shared library missing" },
+#endif
+ { 0, 0, NULL },
+};
+
+
+/*
+ * Return a string describing an error. The returned string may be a
+ * pointer to a static buffer that will be overwritten on the next call.
+ * Action describes the operation that got the error.
+ */
+
+const char *
+errmsg(int e, int action)
+{
+ struct errname const *ep;
+ static char buf[12];
+
+ for (ep = errormsg ; ep->errcode ; ep++) {
+ if (ep->errcode == e && (ep->action & action) != 0)
+ return ep->msg;
+ }
+ fmtstr(buf, sizeof buf, "error %d", e);
+ return buf;
+}