X-Git-Url: https://git.phdru.name/?a=blobdiff_plain;f=mimedecode.docbook;h=9acc3209b228b2c4c25898205fc9f46251bb0231;hb=bd89029f8a4ae4c98c14e105c3e9e987c69d0805;hp=90eb11eb5f46e9bdf8e2d59669cd947de228b67b;hpb=64bde269318eb10622bdc5477ae30df8b6592e15;p=mimedecode.git diff --git a/mimedecode.docbook b/mimedecode.docbook index 90eb11e..9acc320 100644 --- a/mimedecode.docbook +++ b/mimedecode.docbook @@ -41,20 +41,62 @@ + + + - + + + + + + + + + + + + + + + + + + + + + + - + - + - + + + + + + + + + + + + + + + + + + + @@ -70,13 +112,13 @@ DESCRIPTION Mail users, especially in non-English countries, often find that mail -messages arrived in different formats, with different content types, in -different encodings and charsets. Usually it is good because it allows to use -an appropriate format/encoding/whatever. Sometimes, though, some unification is -desirable. For example, one may want to put mail messages into an archive, -make HTML indices, run search indexer, etc. In such situations converting -messages to text in one character set and skipping some binary attachments is -much desirable. + messages arrived in different formats, with different content types, in + different encodings and charsets. Usually it is good because it allows to + use an appropriate format/encoding/whatever. Sometimes, though, some + unification is desirable. For example, one may want to put mail messages + into an archive, make HTML indices, run search indexer, etc. In such + situations converting messages to text in one character set and skipping + some binary attachments is much desirable. @@ -85,21 +127,23 @@ much desirable. This is a program to decode MIME messages. The program expects one input -file (either on command line or on stdin) which is treated as an RFC822 -message, and decodes to stdout or an output file. If the file is not an RFC822 -message it is just copied to the output one-to-one. If the file is a simple -RFC822 message it is decoded as one part. If it is a MIME message with multiple -parts ("attachments") all parts are decoded. Decoding can be controlled by -command-line options. + file (either on command line or on stdin) which is treated as an RFC822 + message, and decodes to stdout or an output file. If the file is not an + RFC822 message it is just copied to the output one-to-one. If the file is a + simple RFC822 message it is decoded as one part. If it is a MIME message + with multiple parts ("attachments") all parts are decoded. Decoding can be + controlled by command-line options. - First, Subject and Content-Disposition headers are examined. If any of those - exists, it is decoded according to RFC2047. Content-Disposition header is - not decoded - only its "filename" parameter. Encoded header parameters - violate the RFC, but widely deployed anyway by ignorant coders who never - even heard about RFCs. Correct parameter encoding specified by RFC2231. This - program decodes RFC2231-encoded parameters, too. + First, for every part the program removes headers and parameters listed with + -r and -R options. Then, Subject and Content-Disposition headers (and all + headers listed with -d and -p options) are examined. If any of those exists, + they are decoded according to RFC2047. Content-Disposition header is not + decoded - only its "filename" parameter. Encoded header parameters violate + the RFC, but widely deployed anyway by ignorant coders who never even heard + about RFCs. Correct parameter encoding specified by RFC2231. This program + decodes RFC2231-encoded parameters, too. @@ -113,16 +157,23 @@ command-line options. than POSIX, please don't ask me; real OS users can consult my example at http://phdru.name/Software/dotfiles/mailcap.html). The decoding process uses the first copiousoutput filter it can find. If - there is no any filter the body just passed as is. + there are no filters the body just passed as is. Then Content-Type header is consulted for charset. If it is not equal to the - current locale charset the body text is recoded. Finally message headers and - the body are flushed to stdout. + current locale charset and recoding is allowed the body text is recoded. + Finally message headers and the body are flushed to stdout. + + + Please be warned that in the following options asterisk is a shell + metacharacter and should be escaped or quoted. Either write -d \*,-h1,-h2 + or -d '*,-h1,-h2' or such. + + OPTIONS @@ -151,8 +202,8 @@ command-line options. -c - Recode different character sets in message body to current default - charset; this is the default. + Recode different character sets in message bodies to the current + default charset; this is the default. @@ -161,7 +212,17 @@ command-line options. -C - Do not recode character sets in message body. + Do not recode character sets in message bodies. + + + + + + -f charset + + + Force this charset to be the current default charset instead of + the current locale. @@ -178,21 +239,25 @@ command-line options. - -f charset + -d header1[,header2,header3...] - Force this charset to be the current default charset instead of - the current locale. + Add the header(s) to a list of headers to decode; initially the + list contains headers "From", "To", "Cc", "Reply-To", + "Mail-Followup-To" and "Subject". - -d header + -d *[,-header1,-header2,-header3...] - Add the header to a list of headers to decode; initially the list - contains headers "From" and "Subject". + This variant completely changes headers decoding. First, the list of + headers to decode is cleared. Then all the headers are decoded + except the given list of exceptions (headers listed with '-'). In + this mode it would be meaningless to give more than one -d options + but the program doesn't enforce it. @@ -207,12 +272,42 @@ command-line options. - -p header:param + -p header1[,header2,header3,...]:param1[,param2,param3,...] + + + Add the parameters(s) to a list of headers parameters to decode; + the parameters will be decoded only for the given header(s). + Initially the list contains header "Content-Type", parameter "name"; + and header "Content-Disposition", parameter "filename". + + + + + + -p *[,-header1,-header2,-header3,...]:param1[,param2,param3,...] + + + Add the parameters(s) to a list of headers parameters to decode; + the parameters will be decoded for all headers except the given + ones. + + + + + + -p header1[,header2,header3,...]:*[,-param1,-param2,-param3,...] + + + Decode all parameters except listed for the given list of headers. + + + + + + -p *[,-header1,-header2,-header3,...]:*[,-param1,-param2,-param3,...] - Add the (header, param) pair to a list of headers' parameters to - decode; initially the list contains header "Content-Disposition", - parameter "filename". + Decode all parameters except listed for all headers (except listed). @@ -221,7 +316,85 @@ command-line options. -P - Clear the list of headers' parameters to decode (make it empty). + Clear the list of headers parameters to decode (make it empty). + + + + + + -r header1[,header2,header3...] + + + Add the header(s) to a list of headers to remove completely; + initially the list is empty. + + + + + + -r *[,-header1,-header2,-header3...] + + + Remove all headers except listed. + + + + + + -R header1[,header2,header3,...]:param1[,param2,param3,...] + + + Add the parameters(s) to a list of headers parameters to remove; + the parameters will be decoded only for the given header(s). + Initially the list is empty. + + + + + + -R *[,-header1,-header2,-header3,...]:param1[,param2,param3,...] + + + + -R header1[,header2,header3,...]:*[,-param1,-param2,-param3,...] + + + + -R *[,-header1,-header2,-header3,...]:*[,-param1,-param2,-param3,...] + + + Remove listed parameters (or all parameters except listed) frome + these headers (or from all headers except listed). + + + + + + --set-header header:value + + + The program sets or changes value for the header to the given value + (only at the top-level message). + + + + + + --set-param header:param=value + + + The program sets or changes value for the header's parameter to the + given value (only at the top-level message). The header must exist. + + + + + + -B mask + + + Append mask to the list of binary content types that will be not + content-transfer-decoded (will be left as base64 or such). @@ -231,8 +404,9 @@ command-line options. Append mask to the list of binary content types; if the message to - decode has a part of this type the program will pass the part as is, - without any additional processing. + decode has a part of this type the program will + content-transfer-decode (base64 or whatever to 8bit binary) it but + pass the part as is, without any further processing. @@ -270,11 +444,42 @@ command-line options. + + --save-headers mask + + + + --save-body mask + + + + --save-message mask + + + Append mask to a list of content types to save to a file; + --save-headers saves only decoded headers of the message (or + subpart); --save-body saves only decoded body; --save-message saves + the entire message or subpart (headers + body). + + + + + + -O dest_dir + + + Set destination directory for the output files; the directory must + exist. Default is current directory. + + + + -o output_file - Useful to set the output file in case of redirected stdin: + Save output to the file related to the destination directory from + option -O. Also useful in case of redirected stdin: mimedecode.py -o output_file < input_file cat input_file | mimedecode.py -o output_file @@ -283,24 +488,24 @@ cat input_file | mimedecode.py -o output_file - The 4 list options (-beit) require more explanation. They allow a user -to control body decoding with great flexibility. Think about said mail -archive; for example, its maintainer wants to put there only texts, convert -Postscript/PDF to text, pass HTML and images as is, and ignore everything -else. Easy: + The 5 list options (-Bbeit) require more explanation. They allow a user to + control body decoding with great flexibility. Think about said mail archive; + for example, its maintainer wants to put there only texts, convert + PDF/Postscript to text, pass HTML and images as is (decoding base64 to html + but left images in base64), and ignore everything else. Easy: - mimedecode.py -t application/postscript -t application/pdf -b text/html - -b 'image/*' -i '*/*' + mimedecode.py -t application/pdf -t application/postscript -b text/html + -B 'image/*' -i '*/*' When the program decodes a message (non-MIME or a non-multipart subpart of a MIME message), it consults Content-Type header. The content type is searched - in all 4 lists, in order "text-binary-ignore-error". If found, appropriate + in all 5 lists, in order "text-binary-ignore-error". If found, appropriate action performed. If not found, the program search the same lists for "type/*" mask (the type of "text/html" is just "text"). If found, appropriate action performed. If not found, the program search the same @@ -310,9 +515,22 @@ else. Easy: - Initially all 4 lists are empty, so without any additional parameters + Initially all 5 lists are empty, so without any additional parameters the program always uses the default decoding. + + + The 3 save list options (--save-headers/body/message) are similar. They make + the program to save every non-multipart subpart (only headers, or body, or + the entire subpart) that corresponds to the given mask to a file. Before + saving the message (or the subpart) is decoded according to all other options + and placed to the output stream as usual. Filename for the file is created + using "filename" parameter from the Content-Disposition header, or "name" + parameter from the Content-Type header if one of those exist; a serial + counter is prepended to the filename to avoid collisions; if there are no + name/filename parameters, the filename is just the serial counter. The file + is saved in the directory set with -O (default is the current directory). + @@ -334,12 +552,13 @@ the program always uses the default decoding. BUGS The program may produce incorrect MIME message. The purpose of the program -is to decode whatever it is possible to decode, not to produce absolutely -correct MIME output. The incorrect parts are obvious - decoded Subject headers -and filenames. Other than that output is correct MIME message. The program does -not try to guess whether the headers are correct. For example, if a message -header states that charset is iso8859-5, but the body is actually in utf-8 -the program will recode the message with the wrong charset. + is to decode whatever it is possible to decode, not to produce absolutely + correct MIME output. The incorrect parts are obvious - decoded + From/To/Cc/Reply-To/Mail-Followup-To/Subject headers and filenames. Other + than that output is correct MIME message. The program does not try to guess + whether the headers are correct. For example, if a message header states + that charset is iso8859-5, but the body is actually in utf-8 the program + will recode the message with the wrong charset.