error.c revision 276038 
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 276038 2014-12-21 23:09:59Z jilles $");
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) __dead2;
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 * Interrupts are disabled; they should be reenabled when the exception is
78 * caught.
79 */
80
81void
82exraise(int e)
83{
84	INTOFF;
85	if (handler == NULL)
86		abort();
87	exception = e;
88	longjmp(handler->loc, 1);
89}
90
91
92/*
93 * Called from trap.c when a SIGINT is received and not suppressed, or when
94 * an interrupt is pending and interrupts are re-enabled using INTON.
95 * (If the user specifies that SIGINT is to be trapped or ignored using the
96 * trap builtin, then this routine is not called.)  Suppressint is nonzero
97 * when interrupts are held using the INTOFF macro.  If SIGINTs are not
98 * suppressed and the shell is not a root shell, then we want to be
99 * terminated if we get here, as if we were terminated directly by a SIGINT.
100 * Arrange for this here.
101 */
102
103void
104onint(void)
105{
106	sigset_t sigs;
107
108	intpending = 0;
109	sigemptyset(&sigs);
110	sigprocmask(SIG_SETMASK, &sigs, NULL);
111
112	/*
113	 * This doesn't seem to be needed, since main() emits a newline.
114	 */
115#if 0
116	if (tcgetpgrp(0) == getpid())
117		write(STDERR_FILENO, "\n", 1);
118#endif
119	if (rootshell && iflag)
120		exraise(EXINT);
121	else {
122		signal(SIGINT, SIG_DFL);
123		kill(getpid(), SIGINT);
124		_exit(128 + SIGINT);
125	}
126}
127
128
129static void
130vwarning(const char *msg, va_list ap)
131{
132	if (commandname)
133		outfmt(out2, "%s: ", commandname);
134	else if (arg0)
135		outfmt(out2, "%s: ", arg0);
136	doformat(out2, msg, ap);
137	out2fmt_flush("\n");
138}
139
140
141void
142warning(const char *msg, ...)
143{
144	va_list ap;
145	va_start(ap, msg);
146	vwarning(msg, ap);
147	va_end(ap);
148}
149
150
151/*
152 * Exverror is called to raise the error exception.  If the first argument
153 * is not NULL then error prints an error message using printf style
154 * formatting.  It then raises the error exception.
155 */
156static void
157exverror(int cond, const char *msg, va_list ap)
158{
159	/*
160	 * An interrupt trumps an error.  Certain places catch error
161	 * exceptions or transform them to a plain nonzero exit code
162	 * in child processes, and if an error exception can be handled,
163	 * an interrupt can be handled as well.
164	 *
165	 * exraise() will disable interrupts for the exception handler.
166	 */
167	FORCEINTON;
168
169#ifdef DEBUG
170	if (msg)
171		TRACE(("exverror(%d, \"%s\") pid=%d\n", cond, msg, getpid()));
172	else
173		TRACE(("exverror(%d, NULL) pid=%d\n", cond, getpid()));
174#endif
175	if (msg)
176		vwarning(msg, ap);
177	flushall();
178	exraise(cond);
179}
180
181
182void
183error(const char *msg, ...)
184{
185	va_list ap;
186	va_start(ap, msg);
187	exverror(EXERROR, msg, ap);
188	va_end(ap);
189}
190
191
192void
193exerror(int cond, const char *msg, ...)
194{
195	va_list ap;
196	va_start(ap, msg);
197	exverror(cond, msg, ap);
198	va_end(ap);
199}
200