1 /* Generic support for headers.
2 Copyright (C) 1997, 1998 Free Software Foundation, Inc.
4 This file is part of Wget.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
36 /* This file contains the generic routines for work with headers.
37 Currently they are used only by HTTP in http.c, but they can be
38 used by anything that cares about RFC822-style headers.
40 Header is defined in RFC2068, as quoted below. Note that this
41 definition is not HTTP-specific -- it is virtually
42 indistinguishable from the one given in RFC822 or RFC1036.
44 message-header = field-name ":" [ field-value ] CRLF
47 field-value = *( field-content | LWS )
49 field-content = <the OCTETs making up the field-value
50 and consisting of either *TEXT or combinations
51 of token, tspecials, and quoted-string>
53 The public functions are header_get() and header_process(), which
57 /* Get a header from read-buffer RBUF and return it in *HDR.
59 As defined in RFC2068 and elsewhere, a header can be folded into
60 multiple lines if the continuation line begins with a space or
61 horizontal TAB. Also, this function will accept a header ending
62 with just LF instead of CRLF.
64 The header may be of arbitrary length; the function will allocate
65 as much memory as necessary for it to fit. It need not contain a
66 `:', thus you can use it to retrieve, say, HTTP status line.
68 The trailing CRLF or LF are stripped from the header, and it is
69 zero-terminated. #### Is this well-behaved? */
71 header_get (struct rbuf *rbuf, char **hdr, enum header_get_flags flags)
76 *hdr = (char *)xmalloc (bufsize);
80 /* #### Use DO_REALLOC? */
82 *hdr = (char *)xrealloc (*hdr, (bufsize <<= 1));
83 res = RBUF_READCHAR (rbuf, *hdr + i);
86 if ((*hdr)[i] == '\n')
88 if (!((flags & HG_NO_CONTINUATIONS)
90 || (i == 1 && (*hdr)[0] == '\r')))
93 /* If the header is non-empty, we need to check if
94 it continues on to the other line. We do that by
95 peeking at the next character. */
96 res = rbuf_peek (rbuf, &next);
101 /* If the next character is HT or SP, just continue. */
102 if (next == '\t' || next == ' ')
105 /* The header ends. */
107 /* Get rid of '\r'. */
108 if (i > 0 && (*hdr)[i - 1] == '\r')
109 (*hdr)[i - 1] = '\0';
118 DEBUGP (("%s\n", *hdr));
122 /* Check whether HEADER begins with NAME and, if yes, skip the `:' and
123 the whitespace, and call PROCFUN with the arguments of HEADER's
124 contents (after the `:' and space) and ARG. Otherwise, return 0. */
126 header_process (const char *header, const char *name,
127 int (*procfun) (const char *, void *),
130 /* Check whether HEADER matches NAME. */
131 while (*name && (tolower (*name) == tolower (*header)))
133 if (*name || *header++ != ':')
136 header += skip_lws (header);
138 return ((*procfun) (header, arg));
141 /* Helper functions for use with header_process(). */
143 /* Extract a long integer from HEADER and store it to CLOSURE. If an
144 error is encountered, return 0, else 1. */
146 header_extract_number (const char *header, void *closure)
148 const char *p = header;
151 for (result = 0; ISDIGIT (*p); p++)
152 result = 10 * result + (*p - '0');
156 *(long *)closure = result;
160 /* Strdup HEADER, and place the pointer to CLOSURE. */
162 header_strdup (const char *header, void *closure)
164 *(char **)closure = xstrdup (header);
168 /* Skip LWS (linear white space), if present. Returns number of
169 characters to skip. */
171 skip_lws (const char *string)
173 const char *p = string;
175 while (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n')