diplodocus.org Git - nmh/blob - man/show.man

   1 .TH SHOW %manext1% 2016-03-24 "%nmhversion%"
   2 .
   3 .\" %nmhwarning%
   4 .
   5 .SH NAME
   6 show \- show (display) nmh messages
   7 .SH SYNOPSIS
   8 .HP 5
   9 .na
  10 .B show
  11 .RB [ \-help ]
  12 .RB [ \-version ]
  13 .RI [ +folder ]
  14 .RI [ msgs ]
  15 .RB [ \-draft ]
  16 .RB [\-showproc
  17 .IR program ]
  18 .RB [ \-showmimeproc
  19 .IR program ]
  20 .RB [ \-header " | " \-noheader ]
  21 .RB [ \-checkmime " | " \-nocheckmime ]
  22 .RB [ \-concat " | " \-noconcat ]
  23 [switches\ for
  24 .I showproc
  25 or
  26 .IR showmimeproc ]
  27 .ad
  28 .SH DESCRIPTION
  29 .B show
  30 lists each of the specified messages to the standard output
  31 (typically, the terminal).
  32 .PP
  33 By default, text (non-MIME) messages are filtered and displayed by
  34 the
  35 .B nmh
  36 command
  37 .BR mhl .
  38 This command will display text
  39 messages in a nice, uniform format.  It also allows you to configure
  40 the format of the displayed messages and which headers fields are
  41 shown.  See the
  42 .IR mhl (1)
  43 manual page for the details about this
  44 command.  This default can be changed by defining the
  45 .I showproc
  46 profile component.  Any switches not recognized by
  47 .BR show ,
  48 as well as
  49 .B \-header
  50 and
  51 .BR \-noheader ,
  52 are
  53 passed along to that program.  To override the default and the
  54 .I showproc
  55 profile component, use the
  56 .B \-showproc
  57 .I program
  58 switch.  For example,
  59 .B \-showproc
  60 .I more
  61 will cause the
  62 .B more
  63 program to list the messages with no reformatting.  Normally, this
  64 program is specified as the
  65 .I showproc
  66 in the user's
  67 .IR \&.mh_profile ,
  68 rather than using a command line switch.
  69 .PP
  70 By default, non-text messages (MIME messages with multi-media
  71 contents) are processed and displayed by the
  72 .B nmh
  73 command
  74 .BR mhshow .
  75 See the
  76 .IR mhshow (1)
  77 manual page for details
  78 about this command.  This default can changed by defining the
  79 .I showmimeproc
  80 profile component.  Any switches not recognized
  81 by
  82 .B show
  83 are passed along to that program.  To override this
  84 default and the
  85 .B showmimeproc
  86 profile component, use the
  87 .B \-showmimeproc
  88 .I program
  89 switch.
  90 .PP
  91 Note that in some cases,
  92 .B show
  93 may invoke the
  94 .I showmimeproc
  95 even for textual contents.  This will happen for text messages that
  96 specify a transfer encoding (such as MIME quoted-printable or
  97 base64) or specify a character set that
  98 .B show
  99 doesn't believe
 100 can be displayed natively.  The appropriate
 101 .IR locale (1)
 102 environment variables
 103 should be set to the terminal's native character set to avoid
 104 gratuitous invocations of the
 105 .IR showmimeproc .
 106 See the
 107 .IR locale (1)
 108 man page for details about these environment variables.
 109 .PP
 110 The option
 111 .B \-checkmime
 112 (set by default) instructs
 113 .B show
 114 to
 115 test if any of the messages to be displayed are non-text (MIME)
 116 messages.  If any are non-text, they are displayed by the program
 117 .IR showmimeproc ,
 118 else they are displayed by the program
 119 .IR showproc .
 120 The option
 121 .B \-nocheckmime
 122 disables this test and instructs
 123 .B show
 124 to use
 125 .IR showproc ,
 126 regardless of whether
 127 any of the messages are non-text (MIME) messages.
 128 .P
 129 The
 130 .B \-noshowproc
 131 switch will disable any formatting or paging of
 132 messages.  It is equivalent to
 133 .B \-nocheckmime
 134 .B \-showproc
 135 .IR cat .
 136 It is still accepted, but should be considered (somewhat) obsolete.
 137 .PP
 138 The
 139 .B \-header
 140 switch tells
 141 .B show
 142 to display a one-line
 143 description of the message being shown.  This description includes
 144 the folder and the message number.
 145 .PP
 146 By default
 147 .B show
 148 will concatenate all content under one pager.  If you want each part to
 149 displayed separately, you can override the default behavior with
 150 .B \-noconcat.
 151 .PP
 152 If no `msgs' are specified, the current message is used.  Although
 153 it depends on the specific
 154 .I showproc
 155 or
 156 .IR showmimeproc ,
 157 in the default setup when more than one message is specified, you
 158 will be prompted for a <RETURN> prior to listing each message.
 159 Each message will be listed a page at a time, and when the end of
 160 page is reached, the program will wait for a <SPACE> or <RETURN>.
 161 If a <RETURN> is entered, it will print the next line, whereas
 162 <SPACE> will print the next screenful.
 163 .PP
 164 If the standard output is not a terminal, no queries are made, and
 165 each file is listed with a one-line header and two lines of
 166 separation.
 167 .PP
 168 .RB \*(lq "show \-draft" \*(rq
 169 will list the file <mh-dir>/draft if it
 170 exists.
 171 .PP
 172 If the profile entry \*(lqUnseen\-Sequence\*(rq is present and
 173 non-empty, then
 174 .B show
 175 will remove each of the messages shown
 176 from each sequence named by the profile entry.
 177 .SH FILES
 178 .fc ^ ~
 179 .nf
 180 .ta \w'%nmhetcdir%/ExtraBigFileName  'u
 181 ^$HOME/.mh_profile~^The user profile
 182 .fi
 183 .SH "PROFILE COMPONENTS"
 184 .fc ^ ~
 185 .nf
 186 .ta 2.4i
 187 .ta \w'ExtraBigProfileName  'u
 188 ^Path:~^To determine the user's nmh directory
 189 ^Current\-Folder:~^To find the default current folder
 190 ^Unseen\-Sequence:~^To name sequences denoting unseen messages
 191 ^showproc:~^Program to show text (non-MIME) messages
 192 ^showmimeproc:~^Program to show non-text (MIME) messages
 193 .fi
 194 .SH "SEE ALSO"
 195 .IR mhl (1),
 196 .IR mhshow (1),
 197 .IR next (1),
 198 .IR prev (1),
 199 .IR scan (1)
 200 .SH DEFAULTS
 201 .nf
 202 .RB ` +folder "' defaults to the current folder"
 203 .RB ` msgs "' defaults to cur"
 204 .RB ` \-checkmime '
 205 .RB ` \-header '
 206 .RB ` \-concat '
 207 .fi
 208 .SH CONTEXT
 209 If a folder is given, it will become the current folder.  The last
 210 message selected will become the current message.
 211 .SH BUGS
 212 The
 213 .B \-header
 214 switch doesn't work when `msgs' expands to more than
 215 one message.  If the
 216 .I showproc
 217 is
 218 .BR mhl ,
 219 then this problem can
 220 be circumvented by referencing the \*(lqmessagename\*(rq field in the
 221 .B mhl
 222 format file.
 223 .PP
 224 .B show
 225 updates the user's context before showing the message.
 226 Hence
 227 .B show
 228 will mark messages as seen prior to the user actually
 229 seeing them.  This is generally not a problem, unless the user relies
 230 on the \*(lqunseen\*(rq messages mechanism, and interrupts
 231 .B show
 232 while it is showing \*(lqunseen\*(rq messages.
 233 .PP
 234 If your
 235 .I showproc
 236 is
 237 .B mhl
 238 (the default), then
 239 .B show
 240 uses
 241 a built-in
 242 .BR mhl :
 243 it does not actually run the
 244 .B mhl
 245 program.
 246 Hence, if you define your own
 247 .BR showproc ,
 248 don't call it
 249 .B mhl
 250 since
 251 .B show
 252 won't run it.
 253 .PP
 254 If your
 255 .I showproc
 256 is the pager
 257 .BR more ,
 258 then avoid running
 259 .B show
 260 in the background with only its standard output piped to
 261 another process, as in
 262 .PP
 263 .RS 5
 264 show | imprint &
 265 .RE
 266 .PP
 267 Due to a bug in
 268 .BR more ,
 269 show will go into a \*(lqtty input\*(rq state.
 270 To avoid this problem, re-direct
 271 .BR show 's
 272 diagnostic output as well.
 273 For users of
 274 .BR csh :
 275 .PP
 276 .RS 5
 277 show |& imprint &
 278 .RE
 279 .PP
 280 For users of
 281 .BR sh :
 282 .PP
 283 .RS 5
 284 show 2>&1 | imprint &
 285 .RE