xref: /freebsd/bin/sh/error.c (revision 66e576525d35c68fcb86f142ebaa5a448555c0c7)
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
35 static char sccsid[] = "@(#)error.c	8.2 (Berkeley) 5/4/95";
36 #endif
37 #endif /* not lint */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
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 
63 struct jmploc *handler;
64 volatile sig_atomic_t exception;
65 volatile sig_atomic_t suppressint;
66 volatile sig_atomic_t intpending;
67 char *commandname;
68 
69 
70 static 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 
81 void
82 exraise(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.  (If the user specifies
94  * that SIGINT is to be trapped or ignored using the trap builtin, then
95  * this routine is not called.)  Suppressint is nonzero when interrupts
96  * are held using the INTOFF macro.  If SIGINTs are not suppressed and
97  * the shell is not a root shell, then we want to be terminated if we
98  * get here, as if we were terminated directly by a SIGINT.  Arrange for
99  * this here.
100  */
101 
102 void
103 onint(void)
104 {
105 	sigset_t sigs;
106 
107 	/*
108 	 * The !in_dotrap here is safe.  The only way we can arrive here
109 	 * with in_dotrap set is that a trap handler set SIGINT to SIG_DFL
110 	 * and killed itself.
111 	 */
112 
113 	if (suppressint && !in_dotrap) {
114 		intpending++;
115 		return;
116 	}
117 	intpending = 0;
118 	sigemptyset(&sigs);
119 	sigprocmask(SIG_SETMASK, &sigs, NULL);
120 
121 	/*
122 	 * This doesn't seem to be needed, since main() emits a newline.
123 	 */
124 #if 0
125 	if (tcgetpgrp(0) == getpid())
126 		write(STDERR_FILENO, "\n", 1);
127 #endif
128 	if (rootshell && iflag)
129 		exraise(EXINT);
130 	else {
131 		signal(SIGINT, SIG_DFL);
132 		kill(getpid(), SIGINT);
133 	}
134 }
135 
136 
137 /*
138  * Exverror is called to raise the error exception.  If the first argument
139  * is not NULL then error prints an error message using printf style
140  * formatting.  It then raises the error exception.
141  */
142 static void
143 exverror(int cond, const char *msg, va_list ap)
144 {
145 	/*
146 	 * An interrupt trumps an error.  Certain places catch error
147 	 * exceptions or transform them to a plain nonzero exit code
148 	 * in child processes, and if an error exception can be handled,
149 	 * an interrupt can be handled as well.
150 	 *
151 	 * exraise() will disable interrupts for the exception handler.
152 	 */
153 	FORCEINTON;
154 
155 #ifdef DEBUG
156 	if (msg)
157 		TRACE(("exverror(%d, \"%s\") pid=%d\n", cond, msg, getpid()));
158 	else
159 		TRACE(("exverror(%d, NULL) pid=%d\n", cond, getpid()));
160 #endif
161 	if (msg) {
162 		if (commandname)
163 			outfmt(out2, "%s: ", commandname);
164 		doformat(out2, msg, ap);
165 		out2c('\n');
166 	}
167 	flushall();
168 	exraise(cond);
169 }
170 
171 
172 void
173 error(const char *msg, ...)
174 {
175 	va_list ap;
176 	va_start(ap, msg);
177 	exverror(EXERROR, msg, ap);
178 	va_end(ap);
179 }
180 
181 
182 void
183 exerror(int cond, const char *msg, ...)
184 {
185 	va_list ap;
186 	va_start(ap, msg);
187 	exverror(cond, msg, ap);
188 	va_end(ap);
189 }
190