X-Git-Url: https://diplodocus.org/git/nmh/blobdiff_plain/fbcd71b31868c9969836b00a90a0bf32b13111ef..7711f3fc00259e55f630cfe6104eff3083dc9d77:/man/mhshow.man diff --git a/man/mhshow.man b/man/mhshow.man index f55fbfe6..67516be5 100644 --- a/man/mhshow.man +++ b/man/mhshow.man @@ -1,4 +1,4 @@ -.TH MHSHOW %manext1% "May 4, 2013" "%nmhversion%" +.TH MHSHOW %manext1% "April 9, 2014" "%nmhversion%" .\" .\" %nmhwarning% .\" @@ -18,10 +18,16 @@ mhshow \- display MIME messages .RB [ \-type .IR content ] \&... -.RB [ \-serialonly " | " \-noserialonly ] -.RB [ \-pause " | " \-nopause ] +.RB [ \-prefer +.IR content ] +\&... +.RB [ \-concat " | " \-noconcat ] +.RB [ \-textonly " | " \-notextonly ] +.RB [ \-inlineonly " | " \-noinlineonly ] .RB [ \-form .IR formfile ] +.RB [ \-markform +.IR formfile ] .RB [ \-rcache .IR policy ] .RB [ \-wcache @@ -46,16 +52,34 @@ message headers as specified in RFC 2047. .PP By default .B mhshow -will display all parts of a multipart -message. By using the +will display only text parts of a message that are not marked as attachments. +This behavior can be changed by the +.B \-notextonly +and +.B \-noinlineonly +switches. +In addition, by using the .B \-part and .B \-type switches, you may -limit the scope of +further limit the scope of .B mhshow to particular subparts (of a -multipart content) and/or particular content types. +multipart content) and/or particular content types. The inclusion of any +.B \-part +or +.B \-type +switches will override the default settings of +.B \-textonly +and +.BR \-inlineonly. +.PP +By default +.B mhshow +will concatenate all content under one pager. If you which each part to +displayed separately, you can override the default behavior with +.B \-noconcat. .PP The option .B \-file @@ -78,18 +102,44 @@ mail drop format to a folder of messages, see .IR inc (1)). .PP +The +.B \-part +switch can be used (one or more times) to restrict the +set of subparts that will be displayed. (Obviously with no +.B \-part +switches, all parts will be considered.) If a +.B \-part +switch specifies a specific subpart (i.e., a "leaf" in the tree of +MIME parts), then that part will always be displayed. If a +.B \-part +switch references a multipart/alternative part, then (in +the absence of a +.B \-type +switch) only the default subpart of that multipart will be displayed. +.PP A part specification consists of a series of numbers separated by dots. For example, in a multipart content containing three parts, these would be named as 1, 2, and 3, respectively. If part 2 was also a multipart content containing two parts, these would be named as 2.1 and 2.2, respectively. Note that the .B \-part -switch is effective for only +switch is effective only for messages containing a multipart content. If a message has some other kind of content, or if the part is itself another multipart content, the .B \-part switch will not prevent the content from being acted upon. .PP +The +.B \-type +switch can also be used to restrict (or, when used in conjunction with +.BR \-part , +to further restrict) the display of parts according to content type. +One or more +.B \-type +switches part will only select the first match +from a multipart/alternative, even if there is more than one +subpart that matches (one of) the given content type(s). +.PP A content specification consists of a content type and a subtype. The initial list of \*(lqstandard\*(rq content types and subtypes can be found in RFC 2046. @@ -116,12 +166,50 @@ A legal MIME message must contain a subtype specification. To specify a content, regardless of its subtype, just use the name of the content, e.g., \*(lqaudio\*(rq. To specify a specific subtype, separate the two with a slash, e.g., \*(lqaudio/basic\*(rq. -Note that regardless of the values given to the `\-type' switch, a +Note that regardless of the values given to the +.B \-type +switch, a multipart content (of any subtype listed above) is always acted upon. -Further note that if the `\-type' switch is used, and it is desirable to -act on a message/external-body content, then the `\-type' switch must +Further note that if the +.B \-type +switch is used, and it is desirable to +act on a message/external-body content, then the +.B \-type +switch must be used twice: once for message/external-body and once for the content externally referenced. +.PP +In the absence of +.BR \-prefer , +.B mhshow +will select the "best" displayable subpart from +multipart/alternative content. The +.B \-prefer +switch can be used (one or more times, in order of descending +preference) to let MH know which content types from a +multipart/alternative MIME part are preferred by the user, in order to +override the default selection for display. For example, mail is +often sent containing both plaintext and HTML-formatted versions of +the same content, and the HTML version is usually indicated to be the +"best" format for viewing. Using \*(lq-prefer text/plain\*(rq will +cause the plaintext version to be displayed if possible, but still +allow display of the HTML part if there is no plaintext subpart +available. Using \*(lq-prefer text/plain -prefer image/png\*(rq +would add a preference for PNG images, which might or might not +ever appear in the same multipart/alternative section with text/plain. +Implementation note: RFC 2046 requires that the subparts +of a multipart/alternative be ordered according to "faithfulness to +the original content", and MH by default selects the subpart ranked +most "faithful" by that ordering. The +.B \-prefer +switch reorders the alternative parts (only internally, never changing +the message file) to move the user's preferred part(s) to the "most +faithful" position. Thus, when viewed by +.BR mhlist , +the ordering of multipart/alternative parts will appear to change when +invoked with or without various +.B \-prefer +switches. .SS "Unseen Sequence" If the profile entry \*(lqUnseen\-Sequence\*(rq is present and non\-empty, then @@ -224,38 +312,43 @@ The display string may contain the following escapes: .PP .RS 5 .nf -.ta \w'%F 'u -%a Insert parameters from Content-Type field -%e exclusive execution -%f Insert filename containing content -%F %e, %f, and stdin is terminal not content -%l display listing prior to displaying content -%p %l, and ask for confirmation -%s Insert content subtype -%d Insert content description -%% Insert the character % +.ta \w'%F 'u +%a Insert parameters from Content-Type field +%{parameter} Insert the parameter value from the Content-Type field +%f Insert filename containing content +%F %f, and stdin is terminal not content +%l display listing prior to displaying content +%s Insert content subtype +%d Insert content description +%% Insert the character % .fi .RE .PP -For those display strings containing the e- or F-escape, -.B mhshow +.B Mhshow will -execute at most one of these at any given time. Although the F-escape -expands to be the filename containing the content, the e-escape has no -expansion as far as the shell is concerned. +execute at most one display string at any given time, and wait for the +current display string to finish execution before executing the next +display string. .PP -When the p-escape prompts for confirmation, typing INTR (usually -control-C) will tell -.B mhshow -not to display that content. -The p-escape can be disabled by specifying the switch -.BR \-nopause . -Further, when -.B mhshow -is display a content, typing QUIT (usually -control-\\) will tell -.B mhshow -to wrap things up immediately. +The {parameter} escape is typically used in a command line argument +that should only be present if it has a non-null value. Its value +will be wrapped with single quotes if the escape is not so wrapped. +Shell parameter expansion can construct the argument only when it is +non-null, e.g., +.PP +.RS 5 +.nf +mhshow-show-text/html: charset=%{charset}; + w3m ${charset:+-I $charset} -T text/html %F +.fi +.RE +.PP +That example also shows the use of indentation to signify continuation: +the two text lines combine to form a single entry. Note that when +dealing with text that has been converted internally by +.IR iconv (3), +the \*(lqcharset\*(rq parameter will reflect the target character set +of the text, rather than the original character set in the message. .PP Note that if the content being displayed is multipart, but not one of the subtypes listed above, then the f- and F-escapes expand to multiple @@ -268,8 +361,8 @@ behaves as if these profile entries were supplied and supported: .PP .RS 5 .nf -mhshow-show-text/plain: %pmoreproc '%F' -mhshow-show-message/rfc822: %pshow -file '%F' +mhshow-show-text/plain: %lmoreproc %F +mhshow-show-message/rfc822: %lshow -file %F .fi .RE .PP @@ -299,44 +392,54 @@ Example entries might be: .RS 5 .nf mhshow-show-audio/basic: raw2audio 2>/dev/null | play -mhshow-show-image: xv '%f' +mhshow-show-image: xv %f mhshow-show-application/PostScript: lpr -Pps .fi .RE .PP -Note that when using the f- or F-escape, it's a good idea to use -single-quotes around the escape. This prevents misinterpretation by -the shell of any funny characters that might be present in the filename. +If an f- or F-escape is not quoted with single quotes, its expansion +will be wrapped with single quotes. .PP Finally, .B mhshow will process each message serially\0--\0it won't start showing the next message until all the commands executed to display the -current message have terminated. In the case of a multipart content -(of any subtype listed above), the content contains advice indicating if -the parts should be displayed serially or in parallel. Because this may -cause confusion, particularly on uni-window displays, the -.B \-serialonly -switch can be given to tell -.B mhshow -to never display parts in parallel. +current message have terminated. .SS "Showing Alternate Character Sets" +If +.B mhshow +was built with +.IR iconv (3), +then all text/plain parts of the message(s) will be displayed using +the character set of the current locale. See the +.IR mhparam (1) +man page for how determine whether your +.B nmh +installation includes +.IR iconv (3) +support. To convert text parts other +than text/plain, or if +.B mhshow +was not built with +.IR iconv , +an external program can be used, as described next. +.PP Because a content of type text might be in a non-ASCII character set, when .B mhshow encounters a \*(lqcharset\*(rq parameter for this content, it checks if your terminal can display this character set natively. -.B mhn -checks this by examining the environment -variable -.BR $MM_CHARSET . -If the value of this environment variable is equal +.B mhshow +checks this by examining the current character set defined by the +.IR locale (1) +environment variables. +If the value of the locale character set is equal to the value of the charset parameter, then .B mhshow assumes it can -display this content without any additional setup. If this environment -variable is not set, +display this content without any additional setup. If the locale is not +set properly, .B mhshow will assume a value of \*(lqUS-ASCII\*(rq. If the character set cannot be displayed natively, then @@ -379,29 +482,24 @@ needed beforehand. Note that many pagers strip off the high-order bit or have problems displaying text with the high-order bit set. However, the pager .B less -has support for single-octet character sets. The source -to -.B less -is available on many ftp sites carrying free software. -In order to view messages sent in the ISO-8859-1 character set using +has support for single-octet character sets. For example, messages +encoded in the ISO-8859-1 character set can be view using .BR less , -.PP -put these lines in your -.I \&.login -file: +with these environment variable settings: .PP .RS 5 .nf -setenv LESSCHARSET latin1 -setenv LESS "-f" +.ta \w'%F 'u +LESSCHARSET latin1 +LESS -f .fi .RE .PP -The first line tells +The first setting tells .B less to use the ISO-8859-1 definition for determining whether a character is \*(lqnormal\*(rq, \*(lqcontrol\*(lq, -or \*(lqbinary\*(rq. The second line tells +or \*(lqbinary\*(rq. The second setting tells .B less not to warn you if it encounters a file that has non-ASCII characters. Then, simply @@ -553,16 +651,59 @@ mhshow-show- .PP need be present in this additional profile. Finally, .B mhshow -will attempt to consult one other additional user profile, -e.g., +will attempt to consult .PP .RS 5 -%etcdir%/mhn.defaults +%nmhetcdir%/mhn.defaults .RE .PP which is created automatically during .B nmh installation. +.PP +See "Profile Lookup" in +.IR mh-profile (5) +for the profile search order, and for how duplicate entries are treated. +.SS Content\-Type Marker +.B mhshow +will display a marker containing information about the part being displayed +next. The default marker can be changed using the +.B \-markform +switch to specify a file containing +.IR mh\-format (5) +instructions to use when displaying the content marker. In addition to +the normal set of +.IR mh\-format (5) +instructions, the following +.I component +escapes are supported: +.PP +.RS 5 +.nf +.ta \w'cdispo- 'u +\w'Returns 'u +.I "Escape Returns Description" +part string MIME part number +content\-type string MIME Content\-Type of part +description string Content\-Description header +disposition string Content disposition (attachment or inline) +ctype- string Value of from Content\-Type header +cdispo- string Value of from + Content\-Disposition header +%(size) integer The size of the decoded part, in bytes +%(unseen) boolean Returns true for suppressed parts +.fi +In this context, the %(unseen) function indicates whether +.B mhshow +has decided to not display a particular part due to the +.B \-textonly +or +.B \-inlineonly +switches. +.RE +All MIME parameters and the \*(lqContent-Description\*(rq header will have +RFC 2231 decoding applied and be converted +to the local character set. +.PP .SH FILES .B mhshow looks for all format files and mhn.defaults in multiple locations: @@ -570,16 +711,17 @@ absolute pathnames are accessed directly, tilde expansion is done on usernames, and files are searched for in the user's .I Mail directory as specified in their profile. If not found there, the directory -.RI \*(lq %etcdir% \*(rq +.RI \*(lq %nmhetcdir% \*(rq is checked. .PP .fc ^ ~ .nf -.ta \w'%etcdir%/ExtraBigFileName 'u +.ta \w'%nmhetcdir%/ExtraBigFileName 'u ^$HOME/\&.mh\(ruprofile~^The user profile ^$MHSHOW~^Additional profile entries -^%etcdir%/mhn.defaults~^System default MIME profile entries -^%etcdir%/mhl.headers~^The headers template +^%nmhetcdir%/mhn.defaults~^System default MIME profile entries +^%nmhetcdir%/mhl.headers~^The headers template +^%nmhetcdir%/mhshow.marker~^Example content marker .fi .SH "PROFILE COMPONENTS" .fc ^ ~ @@ -599,9 +741,11 @@ is checked. ^moreproc:~^Default program to display text/plain content .fi .SH "SEE ALSO" +.IR iconv (3), .IR mhbuild (1), .IR mhl (1), .IR mhlist (1), +.IR mhparam (1), .IR mhstore (1), .IR sendfiles (1) .SH DEFAULTS @@ -609,10 +753,11 @@ is checked. .RB ` +folder "' defaults to the current folder" .RB ` msgs "' defaults to cur" .RB ` \-nocheck ' +.RB ` \-concat ' +.RB ` \-textonly ' +.RB ` \-inlineonly ' .RB ` \-form\ mhl.headers ' -.RB ` \-pause ' .RB ` \-rcache\ ask ' -.RB ` \-noserialonly ' .RB ` \-wcache\ ask ' .fi .SH CONTEXT