Computer Science


SHOW(1)                                                   SHOW(1)

NAME
       show - show (display) messages

SYNOPSIS
       show [+folder] [msgs] [-showproc program]
            [-showmimeproc program] [-header] [-noheader]
            [-draft] [-checkmime] [-nocheckmime]
            [switches for showproc or showmimeproc]
            [-version] [-help]

DESCRIPTION
       Show  lists each of the specified messages to the standard
       output (typically, the terminal).

       By default, text (non-MIME) messages are filtered and dis-
       played  by the nmh command mhl.  This command will display
       text messages in a nice, uniform format.  It  also  allows
       you  to configure the format of the displayed messages and
       which headers fields are shown.   See  the  mhl(1)  manual
       page for the details about this command.  This default can
       be changed by defining  the  showproc  profile  component.
       Any  switches  not  recognized by show are passed along to
       that program.  To override the default  and  the  showproc
       profile  component,  use  the  `-showproc program' switch.
       For example, `-showproc more' will cause the more(1)  pro-
       gram to list the messages with no reformatting.  Normally,
       this program is specified as the showproc  in  the  user's
       .mh_profile, rather than using a command line switch.

       By  default,  non-text messages (MIME messages with multi-
       media contents) are processed and  displayed  by  the  nmh
       command mhn.  See the mhn(1) manual page for details about
       this command.  This default can changed  by  defining  the
       showmimeproc  profile  component.  Any switches not recog-
       nized by show are passed along to that program.  To  over-
       ride  this default and the showmimeproc profile component,
       use the `-showmimeproc program' switch.

       Note that in some cases, show may invoke the  showmimeproc
       even for textual contents.  This will happen for text mes-
       sages that specify  a  transfer  encoding  (such  as  MIME
       quoted-printable  or  base64)  or  specify a character set
       that show doesn't believe can be displayed natively.   The
       environment  variable MM_CHARSET should be set to the ter-
       minal's native character set to avoid  gratuitous  invoca-
       tions  of  the  showmimeproc.   See the mh-profile (5) man
       page for details about this environment variable.

       The option `-checkmime' (set by default) instructs show to
       test  if  any of the messages to be displayed are non-text
       (MIME) messages.  If any are non-text, they are  displayed
       by  the  program  showmimeproc, else they are displayed by
       the program showproc.  The option `-nocheckmime'  disables
       this  test  and instructs show to use showproc, regardless
       of whether any of the messages are  non-text  (MIME)  mes-
       sages.

       The  `-noshowproc'  switch  will disable any formatting or
       paging    of    messages.     It    is    equivalent    to
       `-nocheckmime -showproc cat'.   It  is still accepted, but
       should be considered (somewhat) obsolete.

       If the environment variable NOMHNPROC is set, the test for
       non-text (MIME) messages will be disabled.  This method is
       obsolete.  Use the `-nocheckmime' switch instead.

       The `-header' switch tells  show  to  display  a  one-line
       description  of the message being shown.  This description
       includes the folder and the message number.

       If no `msgs' are specified, the current message  is  used.
       Although  it depends on the specific showproc or showmime-
       proc, in the default setup when more than one  message  is
       specified,  you  will  be prompted for a <RETURN> prior to
       listing each message.  Each message will be listed a  page
       at  a  time, and when the end of page is reached, the pro-
       gram will wait for a <SPACE> or <RETURN>.  If  a  <RETURN>
       is  entered,  it will print the next line, whereas <SPACE>
       will print the next screenful.

       If the standard output is not a terminal, no  queries  are
       made,  and  each file is listed with a one-line header and
       two lines of separation.

       "show -draft" will list  the  file  <mh-dir>/draft  if  it
       exists.

       If  the  profile  entry  "Unseen-Sequence"  is present and
       non-empty, then show will  remove  each  of  the  messages
       shown  from  each  sequence  named  by  the profile entry.
       ^$HOME/.mh_profile~^The user profile ^Path:~^To  determine
       the  user's  nmh  directory  ^Current-Folder:~^To find the
       default   current   folder   ^Unseen-Sequence:~^To    name
       sequences  denoting unseen messages ^showproc:~^Program to
       show text (non-MIME) messages  ^showmimeproc:~^Program  to
       show  non-text  (MIME)  messages  mhl(1), mhn(1), more(1),
       next(1), prev(1), scan(1) `+folder' defaults to  the  cur-
       rent  folder `msgs' defaults to cur `-checkmime' `-header'
       If a folder is given, it will become the  current  folder.
       The  last  message  shown will become the current message.
       The `-header' switch doesn't work when `msgs'  expands  to
       more  than  one  message.  If the showproc is mhl, then is
       problem can be circumvented by referencing  the  "message-
       name" field in the mhl format file.

       Show  updates  the  user's context before showing the mes-
       sage.  Hence show will mark messages as seen prior to  the
       user  actually seeing them.  This is generally not a prob-
       lem, unless the user relies on the "unseen" messages mech-
       anism,  and  interrupts  show while it is showing "unseen"
       messages.

       If your showproc is mhl (the default), then  show  uses  a
       built-in  mhl:  it  does not actually run the mhl program.
       Hence, if you define your own showproc, don't call it  mhl
       since show won't run it.

       If  your  showproc  is  the pager more, then avoid running
       show in the background with only its standard output piped
       to another process, as in

            show | imprint &

       Due  to  a  bug  in  more, show will go into a "tty input"
       state.  To avoid this problem, re-direct show's diagnostic
       output as well.  For users of csh:

            show |& imprint &

       For users of sh:

            show 2>&1 | imprint &

[nmh-0.27]                    MH.6.8                            1

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