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Diffstat (limited to 'vendor/ruby-msg/contrib/rtf2html.c')
| -rw-r--r-- | vendor/ruby-msg/contrib/rtf2html.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/vendor/ruby-msg/contrib/rtf2html.c b/vendor/ruby-msg/contrib/rtf2html.c new file mode 100644 index 000000000..937e22ff1 --- /dev/null +++ b/vendor/ruby-msg/contrib/rtf2html.c @@ -0,0 +1,155 @@ +#include <stdio.h> +#define bool int +#define false 0 +#define true 1 + +// RTF/HTML functions +// -------------------- +// +// Sometimes in MAPI, the PR_BODY_HTML property contains the HTML of a message. +// But more usually, the HTML is encoded inside the RTF body (which you get in the +// PR_RTF_COMPRESSED property). These routines concern the decoding of the HTML +// from this RTF body. +// +// An encoded htmlrtf file is a valid RTF document, but which contains additional +// html markup information in its comments, and sometimes contains the equivalent +// rtf markup outside the comments. Therefore, when it is displayed by a plain +// simple RTF reader, the html comments are ignored and only the rtf markup has +// effect. Typically, this rtf markup is not as rich as the html markup would have been. +// But for an html-aware reader (such as the code below), we can ignore all the +// rtf markup, and extract the html markup out of the comments, and get a valid +// html document. +// +// There are actually two kinds of html markup in comments. Most of them are +// prefixed by "\*\htmltagNNN", for some number NNN. But sometimes there's one +// prefixed by "\*\mhtmltagNNN" followed by "\*\htmltagNNN". In this case, +// the two are equivalent, but the m-tag is for a MIME Multipart/Mixed Message +// and contains tags that refer to content-ids (e.g. img src="cid:072344a7") +// while the normal tag just refers to a name (e.g. img src="fred.jpg") +// The code below keeps the m-tag and discards the normal tag. +// If there are any m-tags like this, then the message also contains an +// attachment with a PR_CONTENT_ID property e.g. "072344a7". Actually, +// sometimes the m-tag is e.g. img src="http://outlook/welcome.html" and the +// attachment has a PR_CONTENT_LOCATION "http://outlook/welcome.html" instead +// of a PR_CONTENT_ID. +// +// This code is experimental. It works on my own message archive, of about +// a thousand html-encoded messages, received in Outlook97 and Outlook2000 +// and OutlookXP. But I can't guarantee that it will work on all rtf-encoded +// messages. Indeed, it used to be the case that people would simply stick +// {\fromhtml at the start of an html document, and } at the end, and send +// this as RTF. If someone did this, then it will almost work in my function +// but not quite. (Because I ignore \r and \n, and respect only \par. Thus, +// any linefeeds in the erroneous encoded-html will be ignored.) + + + + + +// ISRTFHTML -- Given an uncompressed RTF body of the message, this +// function tells you whether it encodes some html. +// [in] (buf,*len) indicate the start and length of the uncompressed RTF body. +// [return-value] true or false, for whether it really does encode some html +bool isrtfhtml(const char *buf,unsigned int len) +{ // We look for the words "\fromhtml" somewhere in the file. + // If the rtf encodes text rather than html, then instead + // it will only find "\fromtext". + const char *c; + for (c=buf; c<buf+len; c++) + { if (strncmp(c,"\\from",5)==0) return strncmp(c,"\\fromhtml",9)==0; + } + return false; +} + + + + +// DECODERTFHTML -- Given an uncompressed RTF body of the message, +// and assuming that it contains encoded-html, this function +// turns it onto regular html. +// [in] (buf,*len) indicate the start and length of the uncompressed RTF body. +// [out] the buffer is overwritten with the HTML version, null-terminated, +// and *len indicates the length of this HTML. +// +// Notes: (1) because of how the encoding works, the HTML version is necessarily +// shorter than the encoded version. That's why it's safe for the function to +// place the decoded html in the same buffer that formerly held the encoded stuff. +// (2) Some messages include characters \'XX, where XX is a hexedecimal number. +// This function simply converts this into ASCII. The conversion will only make +// sense if the right code-page is being used. I don't know how rtf specifies which +// code page it wants. +// (3) By experiment, I discovered that \pntext{..} and \liN and \fi-N are RTF +// markup that should be removed. There might be other RTF markup that should +// also be removed. But I don't know what else. +// +void decodertfhtml(char *buf,unsigned int *len) +{ // c -- pointer to where we're reading from + // d -- pointer to where we're writing to. Invariant: d<c + // max -- how far we can read from (i.e. to the end of the original rtf) + // ignore_tag -- stores 'N': after \mhtmlN, we will ignore the subsequent \htmlN. + char *c=buf, *max=buf+*len, *d=buf; int ignore_tag=-1; + // First, we skip forwards to the first \htmltag. + while (c<max && strncmp(c,"{\\*\\htmltag",11)!=0) c++; + // + // Now work through the document. Our plan is as follows: + // * Ignore { and }. These are part of RTF markup. + // * Ignore \htmlrtf...\htmlrtf0. This is how RTF keeps its equivalent markup separate from the html. + // * Ignore \r and \n. The real carriage returns are stored in \par tags. + // * Ignore \pntext{..} and \liN and \fi-N. These are RTF junk. + // * Convert \par and \tab into \r\n and \t + // * Convert \'XX into the ascii character indicated by the hex number XX + // * Convert \{ and \} into { and }. This is how RTF escapes its curly braces. + // * When we get \*\mhtmltagN, keep the tag, but ignore the subsequent \*\htmltagN + // * When we get \*\htmltagN, keep the tag as long as it isn't subsequent to a \*\mhtmltagN + // * All other text should be kept as it is. + while (c<max) + { if (*c=='{') c++; + else if (*c=='}') c++; + else if (strncmp(c,"\\*\\htmltag",10)==0) + { c+=10; int tag=0; while (*c>='0' && *c<='9') {tag=tag*10+*c-'0'; c++;} + if (*c==' ') c++; + if (tag==ignore_tag) {while (c<max && *c!='}') c++; if (*c=='}') c++;} + ignore_tag=-1; + } + else if (strncmp(c,"\\*\\mhtmltag",11)==0) + { c+=11; int tag=0; while (*c>='0' && *c<='9') {tag=tag*10+*c-'0'; c++;} + if (*c==' ') c++; + ignore_tag=tag; + } + else if (strncmp(c,"\\par",4)==0) {strcpy(d,"\r\n"); d+=2; c+=4; if (*c==' ') c++;} + else if (strncmp(c,"\\tab",4)==0) {strcpy(d," "); d+=3; c+=4; if (*c==' ') c++;} + else if (strncmp(c,"\\li",3)==0) + { c+=3; while (*c>='0' && *c<='9') c++; if (*c==' ') c++; + } + else if (strncmp(c,"\\fi-",4)==0) + { c+=4; while (*c>='0' && *c<='9') c++; if (*c==' ') c++; + } + else if (strncmp(c,"\\'",2)==0) + { unsigned int hi=c[2], lo=c[3]; + if (hi>='0' && hi<='9') hi-='0'; else if (hi>='A' && hi<='Z') hi-='A'; else if (hi>='a' && hi<='z') hi-='a'; + if (lo>='0' && lo<='9') lo-='0'; else if (lo>='A' && lo<='Z') lo-='A'; else if (lo>='a' && lo<='z') lo-='a'; + *((unsigned char*)d) = (unsigned char)(hi*16+lo); + c+=4; d++; + } + else if (strncmp(c,"\\pntext",7)==0) {c+=7; while (c<max && *c!='}') c++;} + else if (strncmp(c,"\\htmlrtf",8)==0) + { c++; while (c<max && strncmp(c,"\\htmlrtf0",9)!=0) c++; + if (c<max) c+=9; if (*c==' ') c++; + } + else if (*c=='\r' || *c=='\n') c++; + else if (strncmp(c,"\\{",2)==0) {*d='{'; d++; c+=2;} + else if (strncmp(c,"\\}",2)==0) {*d='}'; d++; c+=2;} + else {*d=*c; c++; d++;} + } + *d=0; d++; + *len = d-buf; +} + + +void main() +{ + unsigned char buf[1024*1024]; + int len = fread(buf, 1, 1024*1024, stdin); + decodertfhtml(buf, &len); + fwrite(buf, 1, len, stdout); +} |