bin/sh/error.c

   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. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * @(#)error.c  8.2 (Berkeley) 5/4/95
  37  * $FreeBSD: src/bin/sh/error.c,v 1.26 2006/02/04 14:37:50 schweikh Exp $
  38  * $DragonFly: src/bin/sh/error.c,v 1.4 2007/01/06 03:44:04 pavalos Exp $
  39  */
  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 "eval.h"  /* defines commandname */
  51 #include "nodes.h" /* show.h needs nodes.h */
  52 #include "show.h"
  53 #include "trap.h"
  54 #include <signal.h>
  55 #include <stdlib.h>
  56 #include <unistd.h>
  57 #include <errno.h>
  58
  59
  60 /*
  61  * Code to handle exceptions in C.
  62  */
  63
  64 struct jmploc *handler;
  65 volatile sig_atomic_t exception;
  66 volatile sig_atomic_t suppressint;
  67 volatile sig_atomic_t intpending;
  68
  69
  70 static 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
  78 void
  79 exraise(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
  98 void
  99 onint(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  */
 138 static void
 139 exverror(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
 161 void
 162 error(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
 171 void
 172 exerror(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 }