📄 htguess.c
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/* HTGuess.c** STREAM TO GUESS CONTENT-TYPE**** (c) COPYRIGHT MIT 1995.** Please first read the full copyright statement in the file COPYRIGH.** @(#) $Id: HTGuess.c,v 2.36 1999/02/22 22:10:11 frystyk Exp $**** This version of the stream object just writes its input** to its output, but prepends Content-Type: field and an** empty line after it.**** HISTORY:** 8 Jul 94 FM Insulate free() from _free structure element.***//* Library include files */#include "wwwsys.h"#include "WWWUtil.h"#include "WWWLib.h"#include "WWWFile.h"#include "HTGuess.h"#define SAMPLE_SIZE 200 /* Number of chars to look at *//* Stream Object** ------------*/struct _HTStream { const HTStreamClass * isa; HTRequest * request; HTResponse * response; HTFormat output_format; HTStream * output_stream; HTStream * target; BOOL transparent; int cnt; int text_cnt; int lf_cnt; int cr_cnt; int pg_cnt; int ctrl_cnt; int high_cnt; char * write_ptr; char buffer[ SAMPLE_SIZE + 1 ];};#define PUT_CHAR(c) (*me->target->isa->put_character)(me->target,(c))#define PUT_STRING(s) (*me->target->isa->put_string)(me->target,(s))#define PUT_BLOCK(b,l) (*me->target->isa->put_block)(me->target,(b),(l))/* ------------------------------------------------------------------------- */PRIVATE BOOL is_html (char * buf){ char * p = strchr(buf,'<'); if (p && (!strncasecomp(p, "<HTML>", 6) || !strncasecomp(p, "<!DOCTYPE HTML", 13) || !strncasecomp(p, "<HEAD", 5) || !strncasecomp(p, "<TITLE>", 7) || !strncasecomp(p, "<BODY>", 6) || !strncasecomp(p, "<PLAINTEXT>", 11) || (p[0]=='<' && TOUPPER(p[1]) == 'H' && p[3]=='>'))) return YES; else return NO;}PRIVATE int HTGuess_flush (HTStream * me){ if (!me->transparent) { HTResponse * response = me->response; /* ** First we look for magic tokens and evaluate the contents of the buffer ** that we are investigating. */ if (me->cnt) { HTTRACE(STREAM_TRACE, "GUESSING.... Result of content analysis: Text=%d%% Newlines=%d%% Ctrl=%d%% High=%d%%\n" _ (int)(100*me->text_cnt/me->cnt + 0.5) _ (int)(100*me->lf_cnt /me->cnt + 0.5) _ (int)(100*me->ctrl_cnt/me->cnt + 0.5) _ (int)(100*me->high_cnt/me->cnt + 0.5)); } if (!me->ctrl_cnt || me->text_cnt + me->lf_cnt >= 16 * (me->ctrl_cnt + me->high_cnt)) { char *ptr; /* some kind of text */ *me->write_ptr = 0; /* terminate buffer */ if (me->high_cnt > 0) HTResponse_setContentTransferEncoding(response, WWW_CODING_8BIT); else HTResponse_setContentTransferEncoding(response, WWW_CODING_7BIT); if (is_html(me->buffer)) HTResponse_setFormat(response, HTAtom_for("text/html")); else if (!strncmp(me->buffer, "%!", 2)) HTResponse_setFormat(response, HTAtom_for("application/postscript")); else if (strstr(me->buffer, "#define") && strstr(me->buffer, "_width") && strstr(me->buffer, "_bits")) HTResponse_setFormat(response, HTAtom_for("image/x-xbitmap")); else if ((ptr = strstr(me->buffer, "converted with BinHex"))!=NULL) HTResponse_setContentTransferEncoding(response, WWW_CODING_MACBINHEX); else if (!strncmp(me->buffer, "begin ", 6)) HTResponse_setContentTransferEncoding(response, WWW_CODING_BASE64); else HTResponse_setFormat(response, WWW_PLAINTEXT); } else { if (!strncmp(me->buffer, "GIF", 3)) HTResponse_setFormat(response, WWW_GIF); else if (!strncmp(me->buffer, "\377\330\377\340", 4)) HTResponse_setFormat(response, WWW_JPEG); else if (!strcmp(me->buffer, "MM")) /* MM followed by a zero */ HTResponse_setFormat(response, WWW_TIFF); else if (!strncmp(me->buffer, "\211PNG\r\n\032\n", 8)) HTResponse_setFormat(response, WWW_PNG); else if (!strncmp(me->buffer, ".snd", 4)) HTResponse_setFormat(response, WWW_AUDIO); else if (!strncmp(me->buffer, "\037\235", 2)) HTResponse_addEncoding(response, WWW_CODING_COMPRESS); else if (!strncmp(me->buffer, "\037\213", 2)) HTResponse_addEncoding(response, WWW_CODING_GZIP); else HTResponse_setFormat(response, WWW_BINARY); } /* ** If we couldn't find any magic tokens then we try and look at the suffix ** of the URL file name and use our own bindings to see if that gives any ** results. */ if (HTResponse_format(response) == WWW_UNKNOWN) { HTParentAnchor * anchor = HTRequest_anchor(me->request); char * addr = HTAnchor_physical(anchor); HTTRACE(STREAM_TRACE, "GUESSING.... Hmm - trying local bindings\n"); HTBind_getResponseBindings (response, addr); } /* ** If nothing worked then give up and say binary... */ if (HTResponse_format(response) == WWW_UNKNOWN) { HTTRACE(STREAM_TRACE, "GUESSING.... That's it - I'm giving up!\n"); HTResponse_setFormat(response, WWW_BINARY); } HTTRACE(STREAM_TRACE, "Guessed..... Content-Type `%s\'\n" _ HTAtom_name(HTResponse_format(response))); /* ** Set up the new stream stack with the type we figured out */ if ((me->target = HTStreamStack(HTResponse_format(response), me->output_format, me->output_stream, me->request, NO)) == NULL) { HTTRACE(STREAM_TRACE, "HTGuess..... Can't convert media type\n"); me->target = HTErrorStream(); } me->transparent = YES; return PUT_BLOCK(me->buffer, me->cnt); } return HT_OK;}PRIVATE int HTGuess_put_block (HTStream * me, const char * b, int l){ while (!me->transparent && l-- > 0) { int status; if (me->target) { if ((status = HTGuess_flush(me)) != HT_OK) return status; } else { me->cnt++; if (*b == LF) me->lf_cnt++; else if (*b == CR) me->cr_cnt++; else if (*b == 12) me->pg_cnt++; else if (*b =='\t') me->text_cnt++; else if ((unsigned char)*b < 32) me->ctrl_cnt++; else if ((unsigned char)*b < 128) me->text_cnt++; else me->high_cnt++; *me->write_ptr++ = *b++; if (me->cnt >= SAMPLE_SIZE) { if ((status = HTGuess_flush(me)) != HT_OK) return status; } } } if (l > 0) return PUT_BLOCK(b, l); return HT_OK;}PRIVATE int HTGuess_put_character (HTStream * me, char c){ return HTGuess_put_block(me, &c, 1);}PRIVATE int HTGuess_put_string (HTStream * me, const char * s){ return HTGuess_put_block(me, s, (int) strlen(s));}PRIVATE int HTGuess_free (HTStream * me){ int status; if (!me->transparent && (status = HTGuess_flush(me)) != HT_OK) return status; else me->transparent = YES; if ((status = (*me->target->isa->_free)(me->target)) != HT_OK) return status; HT_FREE(me); return HT_OK;}PRIVATE int HTGuess_abort (HTStream * me, HTList * e){ if (me->target) (*me->target->isa->abort)(me->target, e); HT_FREE(me); return HT_ERROR;}/* Guessing stream** ---------------*/PRIVATE const HTStreamClass HTGuessClass ={ "GuessWhat", HTGuess_flush, HTGuess_free, HTGuess_abort, HTGuess_put_character, HTGuess_put_string, HTGuess_put_block};PUBLIC HTStream * HTGuess_new (HTRequest * request, void * param, HTFormat input_format, HTFormat output_format, HTStream * output_stream){ HTStream * me; if ((me = (HTStream *) HT_CALLOC(1,sizeof(HTStream))) == NULL) HT_OUTOFMEM("HTGuess_new"); me->isa = &HTGuessClass; me->request = request; me->response = HTRequest_response(request); me->output_format = output_format; me->output_stream = output_stream; me->write_ptr = me->buffer; return me;}⌨️ 快捷键说明
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