X-Git-Url: https://git.phdru.name/?a=blobdiff_plain;f=mimedecode.docbook;h=9acc3209b228b2c4c25898205fc9f46251bb0231;hb=bd89029f8a4ae4c98c14e105c3e9e987c69d0805;hp=0bfaf9c807ae783d0ce9b5ddc994a7c60aeb703a;hpb=9c35fa7761509941014db31c46ad7a6e5a6e8817;p=mimedecode.git
diff --git a/mimedecode.docbook b/mimedecode.docbook
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--- a/mimedecode.docbook
+++ b/mimedecode.docbook
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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.
@@ -84,45 +126,54 @@ much desirable.
- It is a program to decode MIME messages. The program expects one input file
-(either on the command line or on stdin) which is treated as an RFC822 message,
-and decoded to stdout. If the file is not an RFC822 message it is just piped to
-stdout as is. If the file is a simple RFC822 message it is just decoded as one
-part. If it is a MIME message with multiple parts ("attachments") all parts are
-decoded recursively. Decoding can be controlled by the command-line options.
+ 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.
- 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, especially in the M$ Ophice GUI (often
-referred as "Windoze") world, where programmers are often ignorant lamers 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.
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
-converted to 8bit. 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. (I have no idea how mailcap could be configured on said M$ Ophice
-GUI, please don't ask me; real OS users can consult my example at
-http://phdru.name/Software/dotfiles/mailcap.html).
-The decoding process uses first copiousoutput filter it can find. If there is
-no any filter the body just passed unconverted.
+ starts with looking at header Content-Transfer-Encoding. If the header
+ specifies non-8bit encoding (usually base64 or quoted-printable), the body
+ converted to 8bit. 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. (I have no idea how mailcap can be configured on OSes other
+ 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 are no filters the body just passed as is.
- Then Content-Type header consulted for charset. If it is not equal to
-current default charset the body text recoded. Finally message headers and body
-flushed to stdout.
+ Then Content-Type header is consulted for charset. If it is not equal to the
+ 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 @@ flushed to stdout.
-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 @@ flushed to stdout.
-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 @@ flushed to stdout.
- -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 @@ flushed to stdout.
- -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 @@ flushed to stdout.
-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 @@ flushed to stdout.
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 @@ flushed to stdout.
+
+ --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
@@ -283,36 +488,49 @@ 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 (or its part), it consults
-Content-Type header. The content type is searched in all 4 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 lists for "*/*" mask. If found,
-appropriate action performed. If not found, the program uses default
-action, which is to decode everything to text (if mailcap specifies
-a filter).
+ 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 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
+ lists for "*/*" mask. If found, appropriate action performed. If not found,
+ the program uses default action, which is to decode everything to text (if
+ mailcap specifies a filter).
- 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 koi8-r -
-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.