1 /*
2 * Copyright (c) 2000, 2001, 2002, 2003, 2004 by Martin C. Shepherd.
3 *
4 * All rights reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, and/or sell copies of the Software, and to permit persons
11 * to whom the Software is furnished to do so, provided that the above
12 * copyright notice(s) and this permission notice appear in all copies of
13 * the Software and that both the above copyright notice(s) and this
14 * permission notice appear in supporting documentation.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
19 * OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
20 * HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
21 * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
22 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
23 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
24 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
25 *
26 * Except as contained in this notice, the name of a copyright holder
27 * shall not be used in advertising or otherwise to promote the sale, use
28 * or other dealings in this Software without prior written authorization
29 * of the copyright holder.
30 */
31
32 #include <stdlib.h>
33 #include <string.h>
34 #include <errno.h>
35 #include <stdarg.h>
36
37 #include "errmsg.h"
38
39 /*
40 * Encapsulate the error reporting buffer in an opaque object.
41 */
42 struct ErrMsg {
43 char msg[ERR_MSG_LEN+1]; /* An error message */
44 };
45
46 /*.......................................................................
47 * Create a new error-message object.
48 *
49 * Output:
50 * return ErrMsg * The new object, or NULL on error.
51 */
_new_ErrMsg(void)52 ErrMsg *_new_ErrMsg(void)
53 {
54 ErrMsg *err; /* The object to be returned */
55 /*
56 * Allocate the container.
57 */
58 err = malloc(sizeof(ErrMsg));
59 if(!err) {
60 errno = ENOMEM;
61 return NULL;
62 };
63 /*
64 * Before attempting any operation that might fail, initialize the
65 * container at least up to the point at which it can safely be passed
66 * to del_ErrMsg().
67 */
68 err->msg[0] = '\0';
69 return err;
70 }
71
72 /*.......................................................................
73 * Delete an error-message object.
74 *
75 * Input:
76 * err ErrMsg * The object to be deleted.
77 * Output:
78 * return ErrMsg * The deleted object (always NULL).
79 */
_del_ErrMsg(ErrMsg * err)80 ErrMsg *_del_ErrMsg(ErrMsg *err)
81 {
82 if(err) {
83 free(err);
84 };
85 return NULL;
86 }
87
88 /*.......................................................................
89 * Record the concatenation of a list of string arguments in an error
90 * message object. The last argument must be END_ERR_MSG to terminate
91 * the argument list.
92 *
93 * Input:
94 * err ErrMsg * The error-message container.
95 * ... const char * Zero or more strings to be concatenated in buff[].
96 * ... const char * The last argument must always be END_ERR_MSG to
97 * terminate the argument list.
98 */
_err_record_msg(ErrMsg * err,...)99 void _err_record_msg(ErrMsg *err, ...)
100 {
101 va_list ap; /* The variable argument list */
102 const char *s; /* The string being printed */
103 size_t msglen = 0; /* The total length of the message */
104 /*
105 * Nowhere to record the result?
106 */
107 if(!err) {
108 errno = EINVAL;
109 return;
110 };
111 /*
112 * Concatenate the list of argument strings in err->msg[].
113 */
114 va_start(ap, err);
115 while((s = va_arg(ap, const char *)) != END_ERR_MSG) {
116 /*
117 * How much room is left in the output buffer (note that the output
118 * buffer has ERR_MSG_LEN+1 elements).
119 */
120 int nleft = ERR_MSG_LEN - msglen;
121 /*
122 * How long is the next string to be appended?
123 */
124 size_t slen = strlen(s);
125 /*
126 * If there is any room left, append as much of the string
127 * as will fit.
128 */
129 if(nleft > 0) {
130 int nnew = slen < nleft ? slen : nleft;
131 strncpy(err->msg + msglen, s, nnew);
132 msglen += nnew;
133 };
134 };
135 va_end(ap);
136 /*
137 * Terminate the message.
138 */
139 err->msg[msglen] = '\0';
140 return;
141 }
142
143 /*.......................................................................
144 * Return a pointer to the error message buffer.
145 *
146 * Input:
147 * err ErrMsg * The container of the error message buffer.
148 * Output:
149 * return char * The current error message, or NULL if err==NULL.
150 */
_err_get_msg(ErrMsg * err)151 char *_err_get_msg(ErrMsg *err)
152 {
153 return err ? err->msg : NULL;
154 }
155
156 /*.......................................................................
157 * Replace the current error message with an empty string.
158 *
159 * Input:
160 * err ErrMsg * The container of the error message buffer.
161 */
_err_clear_msg(ErrMsg * err)162 void _err_clear_msg(ErrMsg *err)
163 {
164 if(err)
165 err->msg[0] = '\0';
166 }
167
168