libexplain  1.4.D001
libexplain/output.c
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00001 /*
00002  * libexplain - Explain errno values returned by libc functions
00003  * Copyright (C) 2010, 2013 Peter Miller
00004  * Written by Peter Miller <pmiller@opensource.org.au>
00005  *
00006  * This program is free software; you can redistribute it and/or modify
00007  * it under the terms of the GNU Lesser General Public License as
00008  * published by the Free Software Foundation; either version 3 of the
00009  * License, or (at your option) any later version.
00010  *
00011  * This program is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public License
00017  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
00018  */
00019 
00020 #include <libexplain/ac/assert.h>
00021 #include <libexplain/ac/errno.h>
00022 #include <libexplain/ac/stdlib.h>
00023 
00024 #include <libexplain/output.h>
00025 #include <libexplain/output/stderr.h>
00026 
00027 
00028 explain_output_t *
00029 explain_output_new(const explain_output_vtable_t *vtable)
00030 {
00031     unsigned int    size;
00032     explain_output_t *result;
00033 
00034     assert(vtable);
00035     size = vtable->size;
00036     if (size < sizeof(explain_output_t))
00037         size = sizeof(explain_output_t);
00038     result = malloc(size);
00039     if (!result)
00040         return NULL;
00041     result->vtable = vtable;
00042     result->exit_has_been_used = 0;
00043     return result;
00044 }
00045 
00046 
00047 void
00048 explain_output_method_destructor(explain_output_t *op)
00049 {
00050     if (!op)
00051         return;
00052     if (op == &explain_output_static_stderr)
00053         return;
00054     assert(op->vtable);
00055     if (op->vtable->destructor)
00056         op->vtable->destructor(op);
00057     free(op);
00058 }
00059 
00060 
00061 void
00062 explain_output_method_message(explain_output_t *op, const char *text)
00063 {
00064     int             hold_errno;
00065 
00066     hold_errno = errno;
00067     assert(op);
00068     assert(op->vtable);
00069     assert(op->vtable->message);
00070     assert(text);
00071     op->vtable->message(op, text);
00072     errno = hold_errno;
00073 }
00074 
00075 
00076 void _exit(int);
00077 
00078 
00079 void
00080 explain_output_method_exit(explain_output_t *op, int status)
00081 {
00082     assert(op);
00083     assert(op->vtable);
00084     if (op->vtable->exit)
00085         op->vtable->exit(op, status);
00086 
00092     if (op->exit_has_been_used)
00093         _exit(status);
00094 
00095     /*
00096      * 1. We call ::exit if they didn't supply an exit method.
00097      * 2. We ::exit if their exit method returns, because the rest of
00098      *    the libexplain code assumes that exit means ::exit.
00099      */
00100     exit(status);
00101     op->exit_has_been_used = 1;
00102 }
00103 
00104 
00105 /* vim: set ts=8 sw=4 et : */