Annotation of libwww/Library/src/HTError.html, revision 2.28
2.1 frystyk 1: <HTML>
2: <HEAD>
2.26 frystyk 3: <TITLE>Error Manager</TITLE>
2.28 ! frystyk 4: <!-- Changed by: Henrik Frystyk Nielsen, 6-Sep-1995 -->
2.1 frystyk 5: <NEXTID N="z1">
6: </HEAD>
7: <BODY>
2.18 frystyk 8:
2.9 frystyk 9: <H1>Reporting Errors and Messages to the Client</H1>
2.1 frystyk 10:
2.18 frystyk 11: <PRE>
12: /*
2.22 frystyk 13: ** (c) COPYRIGHT MIT 1995.
2.18 frystyk 14: ** Please first read the full copyright statement in the file COPYRIGH.
15: */
16: </PRE>
17:
2.15 frystyk 18: This module maintaines a list of error messages that might occur
19: during load of a requested URL. The error list is put out to standard
20: output by a simple function that easily can be overwritten by a smart
2.28 ! frystyk 21: server or client. <P>
2.18 frystyk 22:
23: This module is implemented by <A HREF="HTError.c">HTError.c</A>, and
24: it is a part of the <A
2.27 frystyk 25: HREF="http://www.w3.org/pub/WWW/Library/">
2.25 frystyk 26: W3C Reference Library</A>.
2.4 frystyk 27:
2.1 frystyk 28: <PRE>
29: #ifndef HTERROR_H
30: #define HTERROR_H
2.20 frystyk 31:
2.28 ! frystyk 32: #include "HTReq.h"
2.1 frystyk 33: </PRE>
34:
2.24 frystyk 35: <A NAME="errorinfo"><H2>Data Structures</H2></A>
2.1 frystyk 36:
2.15 frystyk 37: The basic data structure is HTErrorInfo, but in addition the following
38: types are used:
2.1 frystyk 39:
2.3 frystyk 40: <H3>Error Numbers</H3>
2.1 frystyk 41:
2.15 frystyk 42: <NOTE><B>Note: </B></NOTE> All non-HTTP error codes have index numbers
43: > HTERR_HTTP_CODES, and they will not be shown in the error-message
44: generated.
45:
2.1 frystyk 46: <PRE>
47: typedef enum _HTErrorElement {
48: HTERR_OK = 0, /* 200 */
49: HTERR_CREATED, /* 201 */
50: HTERR_ACCEPTED, /* 202 */
51: HTERR_PARTIAL, /* 203 */
2.23 frystyk 52: HTERR_NO_CONTENT, /* 204 */
2.1 frystyk 53: HTERR_MOVED, /* 301 */
54: HTERR_FOUND, /* 302 */
55: HTERR_METHOD, /* 303 */
56: HTERR_NOT_MODIFIED, /* 304 */
57: HTERR_BAD_REQUEST, /* 400 */
58: HTERR_UNAUTHORIZED, /* 401 */
59: HTERR_PAYMENT_REQUIRED, /* 402 */
60: HTERR_FORBIDDEN, /* 403 */
61: HTERR_NOT_FOUND, /* 404 */
2.20 frystyk 62: HTERR_NOT_ALLOWED, /* 405 */
63: HTERR_NONE_ACCEPTABLE, /* 406 */
64: HTERR_PROXY, /* 407 */
65: HTERR_TIMEOUT, /* 408 */
2.1 frystyk 66: HTERR_INTERNAL, /* 500 */
67: HTERR_NOT_IMPLEMENTED, /* 501 */
2.20 frystyk 68: HTERR_BAD_GATE, /* 502 */
69: HTERR_DOWN, /* 503 */
70: HTERR_GATE_TIMEOUT, /* 504 */
2.1 frystyk 71: HTERR_HTTP_CODES_END, /* Put all non-HTTP status codes after this */
72: HTERR_NO_REMOTE_HOST,
2.13 frystyk 73: HTERR_NO_HOST,
2.1 frystyk 74: HTERR_FTP_SERVER,
75: HTERR_FTP_NO_RESPONSE,
76: HTERR_TIME_OUT,
2.2 frystyk 77: HTERR_GOPHER_SERVER,
78: HTERR_INTERRUPTED,
2.13 frystyk 79: HTERR_CON_INTR,
2.2 frystyk 80: HTERR_CSO_SERVER,
2.20 frystyk 81: HTERR_HTTP09,
82: HTERR_BAD_REPLY,
2.16 frystyk 83: HTERR_UNKNOWN_AA,
2.5 frystyk 84: HTERR_NEWS_SERVER,
2.7 frystyk 85: HTERR_FILE_TO_FTP,
2.8 frystyk 86: HTERR_MAX_REDIRECT,
2.16 frystyk 87: HTERR_EOF,
2.14 frystyk 88: HTERR_WAIS_OVERFLOW,
89: HTERR_WAIS_MODULE,
2.12 frystyk 90: HTERR_WAIS_NO_CONNECT,
2.2 frystyk 91: HTERR_SYSTEM,
2.1 frystyk 92: HTERR_ELEMENTS /* This MUST be the last element */
93: } HTErrorElement;
2.19 roeber 94:
2.3 frystyk 95: typedef enum _HTErrSeverity {
96: ERR_FATAL = 0x1,
2.7 frystyk 97: ERR_NON_FATAL = 0x2,
2.20 frystyk 98: ERR_WARN = 0x4,
2.7 frystyk 99: ERR_INFO = 0x8
2.3 frystyk 100: } HTErrSeverity;
101:
102: typedef struct _HTErrorInfo {
2.7 frystyk 103: int handle; /* Unique number in this stack */
2.3 frystyk 104: HTErrorElement element; /* Index number into HTErrorMsgInfo */
105: HTErrSeverity severity; /* A la VMS */
106: BOOL ignore; /* YES if msg should not go to user */
107: void * par; /* Explanation, e.g. filename */
108: unsigned int par_length; /* For copying by generic routine */
109: char * where; /* Which function */
110: } HTErrorInfo;
2.1 frystyk 111: </PRE>
112:
2.3 frystyk 113: <H2>Controling Globals</H2>
114:
2.15 frystyk 115: This variable dictates which errors should be put out when generating
116: the message to the user. The first four enumerations make it possible
117: to see `everything as bad or worse than' this level, e.g.
118: HT_ERR_SHOW_NON_FATAL shows messages of type HT_ERR_SHOW_NON_FATAL and
119: HT_ERR_SHOW_FATAL. <P>
120:
121: <B>Note:</B> The default value is made so that it only puts a message
122: to <EM>stderr</EM> if a `real' error has occurred. If a separate
123: widget is available for information and error messages then probably
124: HT_ERR_SHOW_DETAILED would be more appropriate.
2.3 frystyk 125:
126: <PRE>
127: typedef enum _HTErrorShow {
128: HT_ERR_SHOW_FATAL = 0x1,
129: HT_ERR_SHOW_NON_FATAL = 0x3,
130: HT_ERR_SHOW_WARNING = 0x7,
2.6 frystyk 131: HT_ERR_SHOW_INFO = 0xF,
132: HT_ERR_SHOW_PARS = 0x10,
133: HT_ERR_SHOW_LOCATION = 0x20,
134: HT_ERR_SHOW_IGNORE = 0x40,
135: HT_ERR_SHOW_FIRST = 0x80,
2.15 frystyk 136: HT_ERR_SHOW_LINKS = 0x100,
2.7 frystyk 137: HT_ERR_SHOW_DEFAULT = 0x13,
138: HT_ERR_SHOW_DETAILED = 0x1F,
2.10 frystyk 139: HT_ERR_SHOW_DEBUG = 0x7F
2.3 frystyk 140: } HTErrorShow;
141:
142: extern unsigned int HTErrorShowMask;
143: </PRE>
2.1 frystyk 144:
2.15 frystyk 145: This is the table containing the actual error-messages and links for
146: more information:
2.1 frystyk 147:
148: <PRE>
2.3 frystyk 149: typedef struct _HTErrorMsgInfo {
150: int code; /* Error number */
151: char * msg; /* Short explanation */
152: char * url; /* Explaning URL */
153: } HTErrorMsgInfo;
154:
155: extern HTErrorMsgInfo error_info[];
2.1 frystyk 156: </PRE>
157:
2.3 frystyk 158: <H2>Public Error Functions</H2>
159:
2.1 frystyk 160: <H3>Add an Error Message</H3>
161:
162: This function adds an error message to the error_stack list in the HTRequest
2.3 frystyk 163: structure. It always returns a negative value.
2.1 frystyk 164: <PRE>
2.3 frystyk 165: extern int HTErrorAdd PARAMS(( HTRequest * request,
2.1 frystyk 166: HTErrSeverity severity,
167: BOOL ignore,
168: int element,
169: void * par,
170: unsigned int par_length,
171: char * where));
2.2 frystyk 172: </PRE>
173:
174: <H3>Add a System Error Message</H3>
175:
2.15 frystyk 176: This function adds an error from a system call that initializes errno
177: or equivalent and adds it to the error_stack list in the HTRequest
178: structure. It always returns a negative value.
179:
2.2 frystyk 180: <PRE>
2.3 frystyk 181: extern int HTErrorSysAdd PARAMS(( HTRequest * request,
2.2 frystyk 182: HTErrSeverity severity,
2.20 frystyk 183: int errornumber,
2.2 frystyk 184: BOOL ignore,
185: char * syscall));
2.1 frystyk 186: </PRE>
187:
188: <H3>Ignoring an Error Message</H3>
189:
2.15 frystyk 190: If an error message is not to be send to the user, e.g., output to the
191: stream, then the ignore flag must be turn on. Theese functions turns
192: it on for the latest error appended to the list or an arbitrary error
193: refered to by its handle.
194:
2.1 frystyk 195: <PRE>
2.7 frystyk 196: extern void HTErrorIgnore PARAMS((HTRequest * request, int handle));
197: extern void HTErrorIgnoreLast PARAMS((HTRequest * request));
2.1 frystyk 198: </PRE>
199:
2.15 frystyk 200: <H3>Handling Prefix for Links in Error Message</H3>
201:
202: Two functions handle the URL prefix of the links inside the error
203: message. They are quite obvious:
204:
205: <PRE>
2.17 frystyk 206: extern void HTErrorSetPrefix PARAMS((char *path));
207: extern CONST char *HTErrorGetPrefix NOPARAMS;
2.1 frystyk 208: </PRE>
209:
210: <H3>Freeing an Error List</H3>
211:
2.8 frystyk 212: This is normally done when the HTRequest structure is freed but it might be
213: done at any other time in order to ignore a whole series of errors.
2.1 frystyk 214: <PRE>
2.17 frystyk 215: extern void HTErrorFree PARAMS((HTRequest * request));
2.1 frystyk 216: </PRE>
217:
218: <PRE>
219: #endif
220: </PRE>
221: end
222: </BODY>
223: </HTML>
224:
225:
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