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 */ 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 */ 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 */ 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 */ 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 */ 162 void _err_clear_msg(ErrMsg *err) 163 { 164 if(err) 165 err->msg[0] = '\0'; 166 } 167 168