error.c revision 127958 
1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)error.c	8.2 (Berkeley) 5/4/95";
36#endif
37#endif /* not lint */
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/bin/sh/error.c 127958 2004-04-06 20:06:54Z markm $");
40
41/*
42 * Errors and exceptions.
43 */
44
45#include "shell.h"
46#include "main.h"
47#include "options.h"
48#include "output.h"
49#include "error.h"
50#include "nodes.h" /* show.h needs nodes.h */
51#include "show.h"
52#include "trap.h"
53#include <signal.h>
54#include <stdlib.h>
55#include <unistd.h>
56#include <errno.h>
57
58
59/*
60 * Code to handle exceptions in C.
61 */
62
63struct jmploc *handler;
64volatile sig_atomic_t exception;
65volatile sig_atomic_t suppressint;
66volatile sig_atomic_t intpending;
67char *commandname;
68
69
70static void exverror(int, const char *, va_list) __printf0like(2, 0);
71
72/*
73 * Called to raise an exception.  Since C doesn't include exceptions, we
74 * just do a longjmp to the exception handler.  The type of exception is
75 * stored in the global variable "exception".
76 */
77
78void
79exraise(int e)
80{
81	if (handler == NULL)
82		abort();
83	exception = e;
84	longjmp(handler->loc, 1);
85}
86
87
88/*
89 * Called from trap.c when a SIGINT is received.  (If the user specifies
90 * that SIGINT is to be trapped or ignored using the trap builtin, then
91 * this routine is not called.)  Suppressint is nonzero when interrupts
92 * are held using the INTOFF macro.  If SIGINTs are not suppressed and
93 * the shell is not a root shell, then we want to be terminated if we
94 * get here, as if we were terminated directly by a SIGINT.  Arrange for
95 * this here.
96 */
97
98void
99onint(void)
100{
101	sigset_t sigset;
102
103	/*
104	 * The !in_dotrap here is safe.  The only way we can arrive here
105	 * with in_dotrap set is that a trap handler set SIGINT to SIG_DFL
106	 * and killed itself.
107	 */
108
109	if (suppressint && !in_dotrap) {
110		intpending++;
111		return;
112	}
113	intpending = 0;
114	sigemptyset(&sigset);
115	sigprocmask(SIG_SETMASK, &sigset, NULL);
116
117	/*
118	 * This doesn't seem to be needed, since main() emits a newline.
119	 */
120#if 0
121	if (tcgetpgrp(0) == getpid())
122		write(STDERR_FILENO, "\n", 1);
123#endif
124	if (rootshell && iflag)
125		exraise(EXINT);
126	else {
127		signal(SIGINT, SIG_DFL);
128		kill(getpid(), SIGINT);
129	}
130}
131
132
133/*
134 * Exverror is called to raise the error exception.  If the first argument
135 * is not NULL then error prints an error message using printf style
136 * formatting.  It then raises the error exception.
137 */
138static void
139exverror(int cond, const char *msg, va_list ap)
140{
141	CLEAR_PENDING_INT;
142	INTOFF;
143
144#ifdef DEBUG
145	if (msg)
146		TRACE(("exverror(%d, \"%s\") pid=%d\n", cond, msg, getpid()));
147	else
148		TRACE(("exverror(%d, NULL) pid=%d\n", cond, getpid()));
149#endif
150	if (msg) {
151		if (commandname)
152			outfmt(&errout, "%s: ", commandname);
153		doformat(&errout, msg, ap);
154		out2c('\n');
155	}
156	flushall();
157	exraise(cond);
158}
159
160
161void
162error(const char *msg, ...)
163{
164	va_list ap;
165	va_start(ap, msg);
166	exverror(EXERROR, msg, ap);
167	va_end(ap);
168}
169
170
171void
172exerror(int cond, const char *msg, ...)
173{
174	va_list ap;
175	va_start(ap, msg);
176	exverror(cond, msg, ap);
177	va_end(ap);
178}
179