xref: /freebsd/bin/sh/error.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
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  * 3. 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
35 static char sccsid[] = "@(#)error.c	8.2 (Berkeley) 5/4/95";
36 #endif
37 #endif /* not lint */
38 #include <sys/cdefs.h>
39 /*
40  * Errors and exceptions.
41  */
42 
43 #include "shell.h"
44 #include "eval.h"
45 #include "main.h"
46 #include "options.h"
47 #include "output.h"
48 #include "error.h"
49 #include "nodes.h" /* show.h needs nodes.h */
50 #include "show.h"
51 #include "trap.h"
52 #include <signal.h>
53 #include <stdlib.h>
54 #include <unistd.h>
55 #include <errno.h>
56 
57 
58 /*
59  * Code to handle exceptions in C.
60  */
61 
62 struct jmploc *handler;
63 volatile sig_atomic_t exception;
64 volatile sig_atomic_t suppressint;
65 volatile sig_atomic_t intpending;
66 
67 
68 static void verrorwithstatus(int, const char *, va_list) __printf0like(2, 0) __dead2;
69 
70 /*
71  * Called to raise an exception.  Since C doesn't include exceptions, we
72  * just do a longjmp to the exception handler.  The type of exception is
73  * stored in the global variable "exception".
74  *
75  * Interrupts are disabled; they should be re-enabled when the exception is
76  * caught.
77  */
78 
79 void
80 exraise(int e)
81 {
82 	INTOFF;
83 	if (handler == NULL)
84 		abort();
85 	exception = e;
86 	longjmp(handler->loc, 1);
87 }
88 
89 
90 /*
91  * Called from trap.c when a SIGINT is received and not suppressed, or when
92  * an interrupt is pending and interrupts are re-enabled using INTON.
93  * (If the user specifies that SIGINT is to be trapped or ignored using the
94  * trap builtin, then this routine is not called.)  Suppressint is nonzero
95  * when interrupts are held using the INTOFF macro.  If SIGINTs are not
96  * suppressed and the shell is not a root shell, then we want to be
97  * terminated if we get here, as if we were terminated directly by a SIGINT.
98  * Arrange for this here.
99  */
100 
101 void
102 onint(void)
103 {
104 	sigset_t sigs;
105 
106 	intpending = 0;
107 	sigemptyset(&sigs);
108 	sigprocmask(SIG_SETMASK, &sigs, NULL);
109 
110 	/*
111 	 * This doesn't seem to be needed, since main() emits a newline.
112 	 */
113 #if 0
114 	if (tcgetpgrp(0) == getpid())
115 		write(STDERR_FILENO, "\n", 1);
116 #endif
117 	if (rootshell && iflag)
118 		exraise(EXINT);
119 	else {
120 		signal(SIGINT, SIG_DFL);
121 		kill(getpid(), SIGINT);
122 		_exit(128 + SIGINT);
123 	}
124 }
125 
126 
127 static void
128 vwarning(const char *msg, va_list ap)
129 {
130 	if (commandname)
131 		outfmt(out2, "%s: ", commandname);
132 	else if (arg0)
133 		outfmt(out2, "%s: ", arg0);
134 	doformat(out2, msg, ap);
135 	out2fmt_flush("\n");
136 }
137 
138 
139 void
140 warning(const char *msg, ...)
141 {
142 	va_list ap;
143 	va_start(ap, msg);
144 	vwarning(msg, ap);
145 	va_end(ap);
146 }
147 
148 
149 /*
150  * Exverror is called to raise the error exception.  If the first argument
151  * is not NULL then error prints an error message using printf style
152  * formatting.  It then raises the error exception.
153  */
154 static void
155 verrorwithstatus(int status, const char *msg, va_list ap)
156 {
157 	/*
158 	 * An interrupt trumps an error.  Certain places catch error
159 	 * exceptions or transform them to a plain nonzero exit code
160 	 * in child processes, and if an error exception can be handled,
161 	 * an interrupt can be handled as well.
162 	 *
163 	 * exraise() will disable interrupts for the exception handler.
164 	 */
165 	FORCEINTON;
166 
167 #ifdef DEBUG
168 	if (msg)
169 		TRACE(("verrorwithstatus(%d, \"%s\") pid=%d\n",
170 		    status, msg, getpid()));
171 	else
172 		TRACE(("verrorwithstatus(%d, NULL) pid=%d\n",
173 		    status, getpid()));
174 #endif
175 	if (msg)
176 		vwarning(msg, ap);
177 	flushall();
178 	exitstatus = status;
179 	exraise(EXERROR);
180 }
181 
182 
183 void
184 error(const char *msg, ...)
185 {
186 	va_list ap;
187 	va_start(ap, msg);
188 	verrorwithstatus(2, msg, ap);
189 	va_end(ap);
190 }
191 
192 
193 void
194 errorwithstatus(int status, const char *msg, ...)
195 {
196 	va_list ap;
197 	va_start(ap, msg);
198 	verrorwithstatus(status, msg, ap);
199 	va_end(ap);
200 }
201