X-Git-Url: https://git.phdru.name/?p=mimedecode.git;a=blobdiff_plain;f=mimedecode.docbook;h=29d081d84993ff38e5a618d659545b7b6cd8890e;hp=df8a9443043693f944033e08766569d62976298d;hb=HEAD;hpb=c5e23121c09605e62c32c01fd24acf0e1afc02d6 diff --git a/mimedecode.docbook b/mimedecode.docbook deleted file mode 100644 index df8a944..0000000 --- a/mimedecode.docbook +++ /dev/null @@ -1,649 +0,0 @@ - - - - - - - mimedecode - mimedecode.docbook - - Oleg - Broytman - phd@phdru.name - - - - 2001-2018 - PhiloSoft Design. - - - - - mimedecode - 1 - - - - mimedecode - decode MIME message - - - - - mimedecode - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - input_file - output_file - - - - - - -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. - - - - Here is a solution - mimedecode! - - - - 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 non-multipart subparts are decoded. - Decoding can be controlled by the command-line options. - - - - 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 (if it was not listed in option -d) - 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. - - - - Then the body of the message (or the current part) is decoded. Decoding - starts with looking at header Content-Transfer-Encoding. If the header - specifies non-8bit encoding (usually base64 or quoted-printable), the body - is converted to 8bit (can be prevented with -B). Then if its content type - is multipart (multipart/related or multipart/mixed, e.g) every part is - recursively decoded. If it is not multipart, mailcap database is consulted - to find a way to convert the body to plain text (can be prevented with - options -Bbei). (The author has no idea how mailcap can be configured on - OSes other than POSIX, please don't ask; users can consult an example at - http://phdru.name/Software/dotfiles/mailcap.html). - The decoding process uses the first copiousoutput filter it can find. If - 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 and recoding is allowed (see options -Cc) the body - text is recoded. Finally message headers and the body are flushed to stdout. - - - - - - Please be reminded 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 - - - -h - -help - - - Print brief usage help and exit. - - - - - - -V - --version - - - Print version and exit. - - - - - - -c - - - Recode different character sets in message bodies to the current - default charset; this is the default. - - - - - - -C - - - Do not recode character sets in message bodies. - - - - - - -f charset - - - Force this charset to be used for recoding instead of charset from - the current locale. - - - - - - -H hostname - --host=hostname - - - Use this hostname in X-MIME-Autoconverted headers instead of the - current hostname. - - - - - - -d header1[,header2,header3...] - - - 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 *[,-header1,-header2,-header3...] - - - This variant completely changes headers decoding. First, the list of - headers to decode is cleared (as with -D). 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 the limitation. - - - - - - -D - - - Clear the list of headers to decode (make it empty). - - - - - - -p header1[,header2,header3,...]:param1[,param2,param3,...] - - - Add the parameter(s) to a list of headers parameters to decode; - the parameter(s) 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 parameter(s) to a list of headers parameters to decode; - the parameter(s) 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,...] - - - Decode all parameters except listed for all headers (except listed). - - - - - - -P - - - 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 parameter(s) to a list of headers parameters to remove; - the parameter(s) will be removed 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) from - 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). - - - - - - -b mask - - - Append mask to the list of binary content types; if the message to - decode has a part of this type the program content-transfer-decodes - (base64 or whatever to 8bit binary) it and outputs the decoded part - as is, without any further processing. - - - - - - -e mask - - - Append mask to the list of error content types; if the message to - decode has a part of this type the program fails with ValueError. - - - - - - -I mask - - - Append mask to the list of content types to completely ignore. - There will be no output - no headers, no body, no warning. For a - multipart part the entire subtree is removed. - - - - - - -i mask - - - Append mask to the list of content types to ignore; if the message - to decode has a part of this type the program outputs headers but - skips the body. Instead a line "Message body of type %s skipped." - will be issued. - - - - - - -t mask - - - Append mask to the list of content types to convert to text; if the - message to decode has a part of this type the program consults - mailcap database, find the first copiousoutput filter and, if any - filter is found, converts the part. - - - - - - --save-headers mask - - - - --save-body mask - - - - --save-message mask - - - Append mask to lists of content types to save to files; - --save-headers saves only decoded headers of the message (or - the current 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; if the directory - doesn't exist it will be created. Default is the current directory. - - - - - - -o output_file - - - Save output to the file related to the destination directory from - option -O. Also useful in case of redirected stdin: - mimedecode -o output_file < input_file -cat input_file | mimedecode -o output_file - - - - - - - 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 decoding base64 to html but - leaving images encoded, and ignore everything else. This is how it could be - done: - - - - - mimedecode -t application/pdf -t application/postscript -t text/plain - -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 5 lists, in order "text-binary-ignore-error". If found, appropriate - action is performed. If not found, the program searches the same lists for - "type/*" mask (the type of "text/html" is just "text"). If found, - appropriate action is performed. If not found, the program searches the same - lists for "*/*" mask. If found, appropriate action is performed. If not - found, the program uses the default action, which is to decode everything to - text (if mailcap specifies a filter). This algorithm allows more specific - content types to override less specific: -b image/* will be processed - earlier than -B */*. - - - - Options -e/-I/-i can also work with multipart subparts of a MIME message. In - case of -I/-i the entire subtree of that multipart is removed; with -i it's - replaced with ignore warning. - - - - Initially all 5 lists are empty, so without any additional parameters - the program always uses the default decoding (as -t */*). - - - - The 3 save 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: headers + body) that corresponds to the given mask to a file. - Before saving the message (or the subpart) is decoded according to all other - options and is 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, or the name/filename parameters contain forbidden - characters (null, slash, backslash) the filename is just the serial counter. - - - - If the file doesn't have any extensions (no dots in the value of the - name/filename parameters, or the name is just the counter) the program tries - to guess an extension by looking up the content type in mime.types files - including .mime.types file in the user's home directory (if it exists). If - the file has an extension the program doesn't try to verify that it - corresponds to the content type. - - - - The file is saved in the directory set with -O (default is the current - directory). The save options are proceeded before -e options so the user can - save the message that causes an error. - - - - - -ENVIRONMENT - - LANG - LC_ALL - LC_CTYPE - - - Define current locale settings. Used to determine current default charset (if - your Python is properly installed and configured). - - - - - -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 - 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 iso8859-1, but the body (HTML, for example) is actually in - utf-8 the program will recode the message with the wrong charset. - - - - - -AUTHOR - - Oleg - Broytman - phd@phdru.name - - - - - -COPYRIGHT - - Copyright (C) 2001-2018 PhiloSoft Design. - - - - - -LICENSE - - GNU GPL - - - - - -NO WARRANTIES - - This program is distributed in the hope that it will be useful, but WITHOUT - ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - more details. - - - - - -SEE ALSO - - mimedecode home page: - http://phdru.name/Software/Python/#mimedecode - - - -