1CONE(1) CONE(1)
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6 cone - Read and send E-mail messages
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9 cone [ -r ] [ -c directory ]
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13 Cone is a console newsreader and E-mail. It is an interactive program
14 for reading and sending E-mail messages. Cone is designed to be intu‐
15 itive and easy to learn. Starting Cone for the first time displays two
16 links: one for the default system mailbox, and a second link to a quick
17 online tutorial. The online tutorial provides a brief overview of
18 using Cone for reading and sending E-mail.
19 Pressing Q on most screens exits Cone. Cone tries to gracefully log
21 out and shut down all server connections. If Cone cannot log out of a
22 remote server because the remote server is down, press CTRL-C (after Q
23 to terminate Cone).
24 Use CTRL-Z to temporarily suspend Cone and drop back to the shell
26 prompt. Cone remains suspended in the background, and may be restarted
27 by using the shell's fg command.
28 Note: Connections to remote mail servers may be disconnected for
30 inactivity if Cone remains suspended for a prolonged period of
31 time. When suspended, Cone cannot maintain any active connec‐
32 tions to remote mail servers.
33 The -c option names a directory where Cone saves its configuration
35 files, and defaults to $HOME/.cone. The configuration directory will
36 be created, if necessary.
37 The -r option recovers a backup copy of Cone's configuration file.
39 This option is primarily used when remote configuration is enabled, but
40 the folder that contains Cone's configuration on a remote server was
41 deleted, or is not available. In all cases, Cone makes a daily local
42 configuration file backup. The -r option searches for local configura‐
43 tion file backups, and offers an option to restore the backup copy.
44 READING LOCAL MAIL WITH CONE
46 Cone reads local mail from either maildirs (the preferred format) or
47 mailbox files (or "mboxes"). When mboxes are used, Cone does not read
48 the system mailbox file directly (usually /var/spool/something). All
49 messages in the system mailbox are automatically moved to $HOME/Inbox,
50 which is then accessed as if it was the system mailbox. Starting Cone
51 for the first time on an mbox-based system automatically copies all
52 existing mail from the system mailbox file to $HOME/Inbox.
53 This is an intentional design choice. Normal user application cannot
55 create new files in /var/spool; all they can do is read the mailbox
56 file from /var/spool. Therefore, the only way to update the mailbox
57 file is by rewriting it from scratch (more or less). While the mailbox
58 file is in the process of being rewritten, if the Cone process is
59 interrupted, or killed, the resulted in a corrupted system mailbox.
60 There are way to minimize this vulnerability, but it cannot be elimi‐
61 nated completely. Some Linux kernels use an ``OOM killer'' that may
62 terminate any process when the system memory is low. There is no way
63 to completely prevent corrupted system mailbox files on those kernels.
64 Cone uses an alternative way of updating mboxes. Cone updates mboxes
66 by creating a new mbox file separately, then replacing the original
67 mbox file with the new version. Unfortunately this cannot be done with
68 the system mailbox file, because of the restricted access rights on the
69 system spool directory. To solve this problem Cone automatically
70 copies the system mailbox file to $HOME/Inbox, each time the system
71 mailbox file is opened and whenever new mail is available.
72 VIEWING MIME ATTACHMENTS
74 Cone displays text and simple HTML content by itself. Other kinds of
75 attachments may be viewed by using a helper script. Cone invokes a
76 helper script to open a MIME attachment. The helper script's name is
77 ``TYPE.SUBTYPE.filter'', where ``TYPE'' and ``SUBTYPE'' corresponds to
78 the MIME type and subtype, accordingly. Cone looks for helper scripts
79 in $HOME/.cone (or the directory specified by -c) and in
80 /usr/share/cone.
81 For example, a helper script named ``IMAGE.GIF.filter'', if installed,
83 is invoked to process image/gif MIME attachments.
84 HELPER SCRIPTS
86 Cone runs each helper script twice:
87 TYPE.SUBTYPE.filter check type/subtype
89 When the first argument is ``check'', the helper script should termi‐
91 nate with a zero exit code if it is willing to process an attachment
92 whose MIME type is specified by the second argument. A script or a
93 program that's has multiple ``TYPE.SUBTYPE.filter'' links may use the
94 second argument to identify the attachment's mime type. If the helper
95 script is unable to process the attachment, at this time, it should
96 terminate with a non-zero exit code.
97 The default helper script for image attachments terminates with a non-
99 zero exit code if the DISPLAY environment variable is not initialized.
100 When invoked from an X-Windows terminal, image attachments will be
101 automatically displayed; and image attachments are ignored otherwise on
102 non-graphical consoles.
103 TYPE.SUBTYPE.filter filter type/subtype filename
105 If the helper script initially terminates with a zero exit code, it
107 will be invoked again after the MIME attachment is downloaded and
108 decoded. The first argument will be ``filter'', and the attachment's
109 filename is specified by the third argument.
110 Note: This is a temporary file, whose extension will not neces‐
112 sary be the file extension associated with this MIME type.
113 The helper script should read and process the file specified by the
115 third argument. Cone interprets anything the helper script writes to
116 standard output as HTML.
117 Note: Cone waits until the helper script terminates before dis‐
119 playing the rest of the message. Most helper scripts should run
120 in the background. However, note that Cone removes the tempo‐
121 rary file when the original message is closed; the temporary
122 file may be removed any time after the helper script terminates.
123 The helper script should make its own private copy of the file,
124 if necessary.
125 ACTIVATING URLS
127 Cone has limited ability to activate URLs in HTML messages. Cone han‐
128 dles ``mailto:'' URLs by itself. For other URLs Cone runs
129 /usr/share/cone/method.handler with the URL passed as an argument.
130 Cone installs http.handler (hard linked to https.handler). This script
132 checks if firefox or mozilla binaries are found in the current PATH,
133 and runs them.
134 Note: Cone also looks method.handler in $HOME/.cone (or the
136 directory specified by -c) in addition to /usr/share/cone.
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139 $HOME/.cone
140 Configuration files, and other application data. May be modi‐
141 fied by the -c option.
142 /usr/share/cone/IMAGE.GIF.filter, /usr/share/cone/IMAGE.JPEG.filter,
144 /usr/share/cone/IMAGE.PNG.filter, /usr/share/cone/APPLICATION.PDF.fil‐
145 ter
146 Default helper scripts distributed with Cone.
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149 mailtool(1), sendmail(8).
150 10 April 2006 CONE(1)