Difference between revisions of "Mu"

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'''Mu''' is a multi-purpose tool shipped with Mailutils.  It can be used for various mail- and database-related tasks, as well as an auxiliary tool for compiling and linking programs with Mailutils.
#REDIRECT [[Mailutils_(utility)]]
== Syntax ==
<tt>Mu</tt> is a command line tool.  Its invocation syntax is:
mu [''options''] ''command'' [''args'']
where ''options'' are options that affect the behavior of <tt>mu</tt> as a whole, ''command'' instructs it what it is to do and ''args'' are any arguments the ''command'' needs in order to be executed.
The commands are:
:Decodes or encodes email message headers.
:Tests Mailutils access control lists.
:Shows compiler options needed to compile with Mailutils.
:Invokes a DBM management tool.
:Applies a chain of filters to the input.
:Displays a terse help summary.
:Invokes an IMAP4 client shell (in development).
:Displays information about Mailutils compile-time configuration.
:Constructs a [http://www.manpagez.com/man/1/ld ld](1) command line for linking a program with Mailutils.
:Logs information using Mailutils log facility.
:Invokes a POP3 client shell.
:Queries configuration values.
Scans [[wicket]]s for matching URLs
== help ==
The <tt>mu help</tt> command lists all available options and command names along with short descriptions of what each of them does.  It is similar to the <tt>mu --help</tt> option.
A command name can be supplied as an argument to <tt>help</tt>, in which case it will display a help page for that particular command, e.g.:
  mu help ldflags
will output help for the [[#ldflags|ldflags]] command.  It is synonymous to the <tt>--help</tt> option used with that particular command, e.g.: <tt>mu ldflags --help</tt>.
== info ==
The <tt>mu info</tt> command displays information about Mailutils compile-time configuration.  In normal form its output lists a single configuration flag per line, e.g.:
  $ mu info
A configuration flag can consist either of a single word, indicating that a particular capability has been enabled at compile time, or of a keyword/value pair delimited by an equal sign, which indicates a particular value used by default for that feature. For example, <tt>IPV6</tt> means that Mailutils was compiled with support for IPv6, whereas <tt>SYSCONFDIR=/etc</tt> means that the default place for configuration files is in <tt>/etc</tt> directory.
Such short output is convenient for using <tt>mu info</tt> in scripts to decide whether it is possible to use a given feature.  To assist human users, the <tt>--verbose</tt> (<tt>-v</tt>) option is provided.  It prints a short description next to each flag:
  $ mu info --verbose
  VERSION=2.99.93          - Version of this package
  SYSCONFDIR=/etc          - System configuration directory
  MAILSPOOLDIR=/var/mail/  - Default mail spool directory
  SCHEME=mbox              - Default mailbox type
  LOG_FACILITY=mail        - Default syslog facility
  IPV6                      - IPv6 support
  USE_LIBPAM                - PAM support
  HAVE_LIBLTDL              - a portable `dlopen' wrapper library
  WITH_GDBM                - GNU DBM
  WITH_GNUTLS              - TLS support using GNU TLS
  WITH_GSASL                - SASL support using GNU SASL
== cflags ==
The <tt>mu cflags</tt> command shows compiler options needed to compile a C source with Mailutils.  It is intended for use in configuration scripts and Makefiles, e.g.:
  CFLAGS=-g -O2 `mu cflags`
== ldflags ==
The <tt>mu ldflags</tt> command is a counterpart of <tt>cflags</tt> used for linking.  It constructs a [http://man.gnu.org.ua/1/ld ld](1) command line for linking a program with Mailutils.
When used without arguments, it outputs <tt>ld</tt> arguments which would link only with the core Mailutils library [[libmailutils]]:
  $ mu ldflags
  -L/usr/local/lib -lmailutils
This command accepts a number of keywords which allow to select a particular subset of Mailutils libraries to link with.  In particular, the argument <tt>all</tt> instructs it to link in all available libraries:
  $ mu ldflags all
  -L/usr/local/lib -lmu_mbox -lmu_mh -lmu_maildir -lmu_imap -lmu_pop \
  -lmu_mailer -lmu_compat -lmailutils -lmu_auth -lgsasl -lgnutls -lgcrypt \
  -lldap -lgnuradius -lpam -ldl
Other available keywords are:
:Link in the UNIX mbox format support.
:Link in the MH format support.
:Link in the Maildir format support.
:Link in the IMAP protocol support.
:Link in the POP protocol support.
:Link in the NNTP protocol support.
:Enable support for [[mailer]]s.
:Link in the support for [[Sieve]] mail filtering language.
:Link in the support for DBM databases ([[libmu_dbm]] library).
:Provide a compatibility layer for Mailutils 2.x.
:Link in the Mailutils authentication library.
:Provide [[Guile]] language bindings.
:Provide [[Python]] language bindings.
:Link in the [[libmu_cfg|Mailutils configuration library]].
:Link in the library for command line parsing.
== query ==
The <tt>mu query</tt> command queries values from Mailutils configuration files.  It takes one or more [[Configuration Pathname|configuration path]]s as its arguments.  On output, it displays the values it found, each value on a separate line.  If the requested value is a block statement it is displayed in full.  For example, if main configuration file contained:
<source lang="C">
  logging {
    syslog yes;
    facility mail;
  $ mu query .logging.syslog
  syslog yes;
  $ mu query .logging.syslog .logging.facility
  syslog yes;
  facility mail;
  $ mu query .logging
  logging {
    syslog yes;
    facility mail;
Several command line options allow to modify output format.  The <tt>--value</tt> option instructs the command to output only values:
  $ mu query --value .logging.syslog
The <tt>--path</tt> option instructs it to print full path names for each value:
  $ mu query --path .logging.syslog
  logging.syslog: yes
The <tt>--program</tt> option instructs <tt>mu</tt> to behave as if it was called under another program name.  For example, the following command:
  $ mu query --program=pop3d .server.transcript
will return the value of the <tt>server.transcript</tt> statement for <tt>pop3d</tt> utility.
By default, <tt>mu query</tt> operates on the main configuration file.  Another configuration file can be supplied using the <tt>--file</tt> (<tt>-f</tt>) option:
  $ mu query --file /usr/local/etc/file.conf .pidfile
== 2047 ==
The <tt>mu 2047</tt> command is a filter for decoding or encoding email message headers formatted in accordance with [http://www.faqs.org/rfcs/rfc2047.html RFC 2047].  By default, it operates in encode mode and assumes the ''iso-8859-1'' encoding.  If arguments are supplied in the command line, they are treated as the text to operate upon.  Otherwise the command acts as a UNIX filter, reading lines from the standard input and printing results on the standard output.
For example:
  $ mu 2047 'Keld Jørn Simonsen <keld@dkuug.dk>'
  =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld@dkuug.dk>
The decode mode can be requested via the <tt>--decode</tt> (<tt>-d</tt>) option:
  $ mu 2047 --decode '=?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld@dkuug.dk>'
  Keld Jørn Simonsen <keld@dkuug.dk>
The <tt>--charset</tt> (<tt>-c</tt>) option changes the default character set.  It is meaningful both in decode and in encode modes.  In decode mode it instructs the utility to convert the output to the given character set.  In encode mode it indicates the encoding of the input data, which will be reflected in the resulting string:
  $ mu 2047 --charset=utf-8 'Keld Jørn Simonsen <keld@dkuug.dk>'
  =?utf-8?Q?Keld J=C3=B8rn Simonsen <keld@dkuug.dk>?=
The <tt>--encoding</tt> (<tt>-E</tt>) option can be used in encode mode to change the output encoding.  Valid arguments for this option are: <tt>quoted-printable</tt> (the default) or <tt>base64</tt>.
The <tt>--newline</tt> (<tt>-n</tt>) option prints an additional newline character after each line of output.
== filter ==
The <tt>mu filter</tt> command applies a chain of [[filter]]s to the input.  The filters to apply and their arguments are given
in the command line.  The full invocation syntax is:
  mu filter [''option''] ''filter-chain''
The syntax for ''filter-chain'' in Backus-Naur form follows:
<source lang="bnf">
<filter-chain> ::= <filter> | <filter-chain> "+" <filter>
<filter> ::= <filter-spec> <ARG>*
<filter-spec> ::= <WORD> | "~" <WORD>
where <tt><WORD></tt> stands for the filter name and <tt><ARG></tt> represents filter arguments.  To obtain a list of known filter names, run:
  mu filter --list
Filters are applied in the order of their appearence, from left to right and operate in encode mode.  The plus sign has the same meaning as pipe in shell.  The default mode can be changed using the <tt>--decode</tt> (<tt>-d</tt>) and <tt>--encode</tt> (<tt>-e</tt>) options.  Whatever the default mode is, a <tt>~</tt> before filter name reverts the mode for that filter alone.
For example, to encode the contents of file <tt>file.txt</tt> in Base64 run:
  mu filter base64 < file.txt
To convert it to base64 and use CRLF as line delimiters, run:
  mu filter base64 + crlf < file.txt
The following command will decode the produced output:
  mu filter --decode crlf + base64
It can also be written as
  mu filter ~crlf + ~base64
The following example [[Iconv (filter)|converts]] the input from ISO-8859-2 to UTF-8, [[From (filter)|quotes]] eventual <tt>From</tt> occurring at the beginning of a line, encodes the result in [[Base64 (filter)|Base64]] and [[CRLF (filter)|changes]] line delimiters to CRLF:
  mu filter iconv iso-8859-2 utf-8 + from + base64 + crlf
This final example [[Inline-comment|removes UNIX-style comments]] from the input and [[Linecon|joins]] continuation lines:
  mu filter --decode inline-comment -S '#' + linecon
Such invocation can be useful in shell scripts to facilitate configuration file processing.
== acl ==
The <tt>mu acl</tt> command tests Mailutils [[Access Control List|access control lists]].  By default it reads ACL from the Mailutils configiration file section "acl".  The command takes a list of IP addresses as its arguments, applies the ACL to each of these addresses in turn and prints the result.
To select the ACL to test, two options are provided.  The <tt>--file</tt> (<tt>-f</tt>) option supplies the name of configuration file to read instead of the default one.  The <tt>--path</tt> (<tt>-p</tt>) option supplies the [[path]] to the ACL section to use instead of the default ".acl".  For example, to test ACL in section <tt>server</tt> of file <tt>/etc/pop3d.conf</tt> use:
  mu acl --file=/etc/pop3d.conf --path=/server=""/acl ''address''
As an example of its use, consider file <tt>test.conf</tt> with the following contents:
acl {
        deny from;
        deny from;
        log from any "Connect from ${address}";
        allow from;
        allow from;
        deny from any;
Then, running <tt>mu acl --file=test.conf</tt> you will get:
  mu: Connect from deny
More examples:
  $ mu acl --file=test.conf
  mu: Connect from deny
  Testing deny
  Testing deny
  mu: Connect from accept
  mu: Connect from accept
  mu: Connect from accept
The <tt>mu</tt> option <tt>--debug-level</tt> will give you a [[Debug_level#acl|deeper insight]] into the address matching algorithm:
  $ mu --debug-level=acl.trace9 acl --file test.conf
  mu: Checking sockaddr
  mu: 1:deny: Does match no;
  mu: 2:deny: Does match no;
  mu: 3:log: Does any match yes;
  mu: Expanding "Connect from ${address}"
  mu: Expansion: "Connect from".
  mu: Connect from
  mu: 4:accept: Does match no;
  mu: 5:accept: Does match no;
  mu: 6:deny: Does any match yes; deny
== wicket ==
The <tt>mu wicket</tt> command looks up matching URLs in the Mailutils [[Fetching_Mail_with_Movemail#Mailutils Ticket File|ticket file]] (by default, <tt>~/.mu-tickets</tt>) and prints them.  The URLs to look for are supplied in the command line. 
Consider the following ticket file as an example:
Now, running <tt>mu wicket smtp://bar@gnu.org</tt> will show:
smtp://bar@gnu.org: /home/''user''/.mu-tickets:2
which means that this URL matches the line 2 in your <tt>.mu-tickets</tt> file.  The <tt>wicket</tt> command does not show the actual matching line to avoid revealing eventual security-sensitive information.  You can instruct it to do so using the <tt>--verbose</tt> (<tt>-v</tt>) option:
  $ mu wicket -v smtp://bar@gnu.org
  smtp://bar@gnu.org: /home/''user''/.mu-tickets:2: smtp://bar:***@gnu.org
As you see, even in that case the tool hides the actual password part by replacing it with three asteriscs.  If you are working in a secure environment, you can tell <tt>mu wicket</tt> to show passwords as well, by giving the <tt>-v</tt> option twice.
A counterpart of <tt>--verbose</tt> is the <tt>--quite</tt> (<tt>-q</tt>) option, which instructs <tt>wicket</tt> to suppress any output, excepting error messages.  This can be used in scripts, which analyze the <tt>mu</tt> exit code to alter the control flow.
The <tt>mu wicket</tt> tool exits with code 0 if all URLs were matched and with code 1 if some of them were not matched in the ticket file.  If an error occurred, the code 2 is returned.
== dbm ==
The <tt>mu dbm</tt> tool manages DBM files using [[libmu_dbm]].  The invocation syntax is:
  mu dbm ''command'' [''options''] ''file'' [''keys'']
  mu dbm [''options''] ''command'' ''file'' [''keys'']
where ''command'' selects the operation mode, ''options'' modify the tool behavior and ''file'' specifies the DBM file to operate upon.  Some ''command''s allow for optional ''keys'' to be specified.
The ''file'' argument can be either a DBM file name or a [[Database URL]].
=== Create a Database ===
The <tt>create</tt> command and its synonym <tt>load</tt> instruct the tool to create a new database:
  mu dbm create file.db
If the argument file already exists, it will be truncated prior to adding new records to it.
The data to populate the database with are read from the standard input.  The <tt>dbm</tt> tool supports several formats for these data, which are [[#Dump Formats|discussed later]].  In the simplest case (a so called ''format 0.0'') each input line must consist of two fields separated by any amount of whitespace.  The first field is treated as a key and the second one as the corresponding value.
The usual way to read data from a file is, of course, by redirecting the file to the standard input as in:
  mu dbm create file.db < input.txt
There is also a special option for that purpose: <tt>--file</tt> (<tt>-f</tt>).  Thus, the following command is equivalent to the one above:
  mu dbm create --file input.txt file.db
The <tt>--file</tt> option has the advantage that it allows, in conjunction with another options, for copying input file metadata (owner UID, GID and file mode) to the created database.  For example, the following command ensures that the created database file will have the same metadata as the input file:
  mu dbm create --file input.txt --copy-permissions file.db
The <tt>--copy-permissions</tt> (<tt>-P</tt>) option is the one that does the job.
There are also other ways to control mode and ownership of the created database, which are [[#options|described below]].
More advanced dump formats (e.g. [[#Format 1.0|1.0]]) carry additional information about the file, including its original name, ownership and mode.  If input is in one of these formats, the file name argument becomes optional.  If it is not supplied, the name stored in the input stream will be used.  For example, supposing that the file <tt>users.dump</tt> is in format 1.0, the following command suffices to restore the original filename, ownership, mode and, of course, data:
  mu dbm create --file users.dump
=== Add Records to a Database ===
The <tt>add</tt> command adds records to a database.  Records are read from the standard input and must be formatted as for <tt>create</tt> command.
  mu dbm add file.db
If the argument file does not exist, it will be created. 
Adding a record with a key which is already present in the database produces an error.  To replace existing records, use the <tt>replace</tt> command instead. 
The same options that affect the behavior of <tt>create</tt> apply to <tt>add</tt> and <tt>replace</tt> as well, e.g.:
  mu dbm replace --file input.txt --copy-permissions file.db
=== Delete Records ===
To delete records, use the <tt>delete</tt> command.  It reads a list of keys to delete to be specified as arguments in the command line:
  mu dbm delete file.db foo bar
The command above will delete from <tt>file.db</tt> records with keys <tt>foo</tt> and <tt>bar</tt>. 
It is not an error to attempt to delete a key that does not exist in the database, although such use will produce a warning message.
By default, keys are matched literally.  It is also possible to use various pattern matching techniques, depending on the option specified.
<div id="patterns"></div>
The <tt>--glob</tt> (<tt>-G</tt>) option instructs the tool to use UNIX globbing pattern matching.  For example, the command below will delete all keys starting with <tt>foo</tt> and ending with a decimal digit:
  mu dbm delete file.db 'foo*[0-9]'
(note the quoting necessary to prevent shell from interpreting the metacharacters itself).
Another option, <tt>--regex</tt> (<tt>-R</tt>) instructs <tt>mu</tt> to treat keys as extended regular expressions:
  mu dbm delete --regex file.db 'foo.*[0-9]{1,3}'
Both options are affected by the <tt>--ignore-case</tt> (<tt>-i</tt>) option, which turns on case-insensitive matching.
Using pattern matching to delete records can be a risky operation as selecting a wrong pattern will lead to removing wrong records.  It is recommended to first use the [[#List the Database|list mode]] described below to verify that the patterns match the right keys.
=== List the Database ===
The <tt>list</tt> command lists the content of the database:
  mu dbm list file.db
By default, entire content is listed on the standard output in [[#Format 0.0|format 0.0]].
If supplied more than one command line argument, this mode treats the rest of arguments after the database file name as the keys to look for and lists only records with these keys:
  $ mu dbm list file.db foo bar
  foo 1
  bar 56
The <tt>--glob</tt> and <tt>--regex</tt> options instruct the tool to use UNIX globbing or extended regular expression matching, correspondingly.  These are described in detail [[#patterns|above]].
=== Dump the Database ===
The <tt>dump</tt> subcommand dumps the database to the standard output in a format suitable for backup or sending over the network (a [[#Format 1.0|version 1.0]] format).
  mu dbm dump file.db > file.dump
The produced file is suitable for input to the <tt>create</tt> (<tt>load</tt>) command.  Among other uses, this provides for an easy way to convert databases between various formats supported by Mailutils.  For example this is how to convert the database file ''file.db'' to the GDBM database ''new.db'':
  mu dbm dump file.db | mu dbm create gdbm://new.db
Both <tt>list</tt> and <tt>dump</tt> subcommands share the same set of options.  In fact, they are pretty similar, except that use different defaults.  The <tt>list</tt> subcommand is oriented to produce a human-readable output, whereas the <tt>dump</tt> subcommand is oriented towards backup purposes.
=== Dump Formats ===
As of version 2.99.93, <tt>mu dbm</tt> supports three formats for dumping DBM databases.  All three are line-oriented.  Comments are introduced with a sharp (''#'') sign in the column 0 of a line, followed by at least one white space character (space or tab).  Sharp sign followed by a colon (''#:'') introduces a ''pragmatic comment'', which carries some additional information to the loader.
<div id="Format 0.0"></div>
The '''version 0.0''' format is suitable for databases whose records contain only ASCII data.  In this format, each record occupies a separate line, which consists of the key and value separated by one or more whitespace characters.  Empty lines are ignored.  For example:
  $ mu list /etc/mail/users.db
  root    guessme
  smith  pAssword
  qed    fooBar
Output in version 0.0 format is human readable and can be used as input to the [[popauth]] utility.  However, version 0.0 has serious drawbacks.  First of all, it is not suitable for databases that contain binary data.  Secondly, it cannot properly handle keys beginning with a sharp sign or containing whitespace characters.  The version 1.0 format is free from these drawbacks.
<div id="Format 1.0"></div>
The '''version 1.0''' format begins with a ''header'' containing important information about the file, such as its file name, ownership and file mode.  This information is stored in pragmatic comments and allows <tt>mu dbm load</tt> to easily recreate an exact copy of the file.  The following comments are defined:
:Indicates that the data that follow are in version 1.0 format.
:Original database file name, without directory parts.
:Owner UID.
:Owner name.
:Owner GID
:Owner group name.
:File mode in octal
Following this header are actual data.  Each record is output in two parts: key and value.  Each part begins with a '''#:len=''n''''' construct on a line by itself, where '''''n''''' is the length of the data in decimal.  This line is followed by one or more lines of the actual data, encoded in [[Base64 (filter)|base64]].  The data are formatted so that each line does not exceed 76 bytes in length (not counting the terminating newline).  An example of this format follows:
# Database dump file created by GNU Mailutils 2.99.93 on Tue Nov  1 13:28:03 2011
<div id="Format C"></div>
The third format called <tt>C</tt> is designed to allow programmers to create input data for <tt>mu load</tt> using conventional means.  This format represents both key and content as C strings (hence its name), with usual C (literal and octal) escapes to represent non-printable characters.  Records are separated with a single newline character. 
An example dump in this format follows:
# Database dump file created by GNU Mailutils 2.99.95 on Sun Nov 27 02:12:13 2011
=== Exit Codes ===
The table below summarizes exit codes used by <tt>mu dbm</tt>:
{| style="border-collapse: collapse; border-width: 1px; border-style: solid; border-color: #000"
! style="border-style: solid; border-width: 1px"|Code
! style="border-style: solid; border-width: 1px"|Symbolic name
! style="border-style: solid; border-width: 1px"|Meaning
| style="border-style: solid; border-width: 1px"|0
| style="border-style: solid; border-width: 1px"|EX_OK
| style="border-style: solid; border-width: 1px"|Successful termination
| style="border-style: solid; border-width: 1px"|64
| style="border-style: solid; border-width: 1px"|EX_USAGE
| style="border-style: solid; border-width: 1px"|Command line usage error
| style="border-style: solid; border-width: 1px"|65
| style="border-style: solid; border-width: 1px"|EX_DATAERR
| style="border-style: solid; border-width: 1px"|Error in user-supplied data: the input file is badly formatted, or some of the data supplied in the command line are invalid (e.g. user name, uid or the like), etc.
| style="border-style: solid; border-width: 1px"|66
| style="border-style: solid; border-width: 1px"|EX_NOINPUT
| style="border-style: solid; border-width: 1px"|Cannot open input file
| style="border-style: solid; border-width: 1px"|67
| style="border-style: solid; border-width: 1px"|EX_NOUSER
| style="border-style: solid; border-width: 1px"|No such user or UID when trying to set output file ownership
| style="border-style: solid; border-width: 1px"|69
| style="border-style: solid; border-width: 1px"|EX_UNAVAILABLE
| style="border-style: solid; border-width: 1px"|Operation cannot be performed due to some kind of problem (e.g. access to the file denied, etc.)
| style="border-style: solid; border-width: 1px"|70
| style="border-style: solid; border-width: 1px"|EX_SOFTWARE
| style="border-style: solid; border-width: 1px"|Internal software error
| style="border-style: solid; border-width: 1px"|74
| style="border-style: solid; border-width: 1px"|EX_IOERR
| style="border-style: solid; border-width: 1px"|Input/output error
== logger ==
The <tt>mu logger</tt> tool logs information using Mailutils log facility. 
  mu logger [''options''] [''message'']
The ''message'' argument, if supplied, gives the text to log.  If not supplied, the utility reads lines of text from standard input or a file (if the <tt>--file</tt> option is given) and sends them to log:
  # Send text to log
  $ mu logger I am here
  # Log each line from file.txt
  $ mu logger --file file.txt
  # Read stdin and log it:
  $ mu logger
The default logging channel is bound to standard error.  To bind it to syslog, use the <tt>--syslog</tt> command line option. In that case <tt>mu</tt> uses facility <tt>user</tt> and priority <tt>err</tt>.  You can change this by using the <tt>--priority</tt> (<tt>-p</tt>) option.  Its argument is either a syslog facility name or facility and severity names separated by a dot.  Thus, the following invocation will use facility <tt>auth</tt>, severity <tt>info</tt>:
  mu logger --priority auth.info
The syslog tag can be set using the <tt>--tag</tt> (<tt>-t</tt>) option:
  mu logger --tag myprog
The default tag is <tt>mu-logger</tt>.
The <tt>--severity</tt> (<tt>-s</tt>) option sets the Mailutils severity level.  Its argument can be any of the following strings: <tt>debug</tt>, <tt>info</tt>, <tt>notice</tt>, <tt>warning</tt>, <tt>error</tt>, <tt>crit</tt>, <tt>alert</tt>, <tt>emerg</tt>.
Finally, the <tt>--locus</tt> (<tt>-l</tt>) option binds log messages to a location in a file.  Its argument has the following syntax:
where ''file'' is the file name, ''line'' is the line number and optional ''col'' is the column number in that file.
For example, the following invocation:
  mu logger --locus mailutils.rc:34 Suspicious statement
will send the following to the log:
  mu-logger: mailutils.rc:34: Suspicious statement
== pop ==
The <tt>mu pop</tt> command invokes an interactive POP3 client shell.  It reads commands from the standard input, executes them and displays the results on the standard output.  If the standard input is connected to a terminal, the [http://cnswww.cns.cwru.edu/php/chet/readline/readline.html#Command-Line-Editing readline and history] facilities are enabled (provided that Mailutils is configured with GNU Readline).
The <tt>mu pop</tt> commands form two major groups.  The POP3 protocol commands interact with the remote POP3 server and display responses obtained from it.  These commands are named after their POP3 equivalents.  Another group, ''internal commands'', are used to configure the shell itself.
=== POP3 protocol commands ===
;connect [-tls] ''hostname'' [''port'']
:Open connection to ''hostname''.  If the <tt>-tls</tt> option is given, TLS encryption (also known as POPS protocol) will be used.  If ''port'' argument is not given, the command uses port 110 for a plain POP connection or 995 for POPS (if <tt>-tls</tt> is given).
:Start TLS negotiation.  This command is valid only after successful unencrypted connection has been initiated (using <tt>connect</tt> without <tt>-tls</tt> argument).
;user ''name''
:Send user name to the server.  The <tt>pass</tt> command must follow.
;pass [''password'']
:Send password.  This command is valid only after <tt>user</tt>.  If the ''password'' argument is omitted, the shell will ask you to enter it.  While entering, both echoing and history recording will be disabled.  Use this to avoid compromising your password.
;apop ''user'' [''password'']
:Authenticate with APOP.  If the ''password'' argument is omitted, you will be asked to supply it.  While entering, both echoing and history recording will be disabled.
;capa [-reread] [''name''...]
:List server capabilities.  Any number of ''name'' arguments is accepted.  If given, the shell will display only the named capabilities, otherwise it displays entire list.  By default <tt>capa</tt> reuses the response of its previous invocation (if there was any), instead of resending the <tt>CAPA</tt> command to the server.  To force it do so, use the <tt>-reread</tt> option.
:Send a ''no operation''.
:Get the mailbox size and number of messages in it.
;uidl [''number'']
:Shows unique message identifiers.  Without arguments, shows identifiers for each message in the mailbox.  If ''number'' is given, the command returns the UIDL of that particular message only.
;list [''number'']
:Lists messages.  See above for the meaning of ''number''.  Each line of the produced listing contains describes a single message and contains at least the message number and size in bytes.  Depending on the POP3 server implementation, additional fields may be present.  For example, Mailutils '''pop3d''' can also output number of lines in the message in the additional third field.
;retr ''number''
:Retrieve a message.
;top ''msgno'' [''number'']
:Display message headers and first ''number'' (default 5) lines of its body.
;dele ''number''
:Mark message for deletion.
:Remove deletion marks.
:Quit pop3 session.
:Close existing connection.
<div id="pop-internal"></div>
=== Internal commands ===
;verbose [on|off|mask|unmask] [secure [payload]]
Control output verbosity.  Without arguments the <tt>verbose</tt> command shows current settings.
The argument <tt>off</tt> (the default) turns off all additional output.  The <tt>verbose on</tt> command enables POP3 protocol tracing output.  Additional arguments can be used to provide more verbosity.  The <tt>secure</tt> argument enables display of user passwords in the trace output and the <tt>payload</tt> enables showing payload data (e.g. response body sent in the reply to <tt>RETR</tt> command, etc.)  Thus, the full diagnostics output is obtained by
  verbose on secure payload
The <tt>mask</tt> and <tt>unmask</tt> argument allow to disable and enable such additional verbosity.  For example, supposing the command above is in action, the following command
will suppress the display of user passwords in the traces:
  verbose mask secure
Similarly, <tt>verbose unmask secure</tt> will turn it back again.
;prompt ''string''
:Set command prompt.  The argument can contain ''variable references'' in the following forms:
where ''name'' is the variable name.  Such references are expanded to the actual value of the variable at the time of expansion.  The following variables are defined:
{| style="border-collapse: collapse; border-width: 1px; border-style: solid; border-color: #000"
! style="border-style: solid; border-width: 1px"|Variable
! style="border-style: solid; border-width: 1px"|Expansion
| style="border-style: solid; border-width: 1px"|user
| style="border-style: solid; border-width: 1px"|Login name of the authenticated POP3 user.  If the session is not authenticated yet, expands to ''[nouser]''.
| style="border-style: solid; border-width: 1px"|host
| style="border-style: solid; border-width: 1px"|Name of the remote host, or ''[nohost]'' if no connection is established.
| style="border-style: solid; border-width: 1px"|program-name
| style="border-style: solid; border-width: 1px"|Name of the program, as typed on the command line to invoke it.
| style="border-style: solid; border-width: 1px"|canonical-program-name
| style="border-style: solid; border-width: 1px"|''mu''
| style="border-style: solid; border-width: 1px"|package
| style="border-style: solid; border-width: 1px"|''Mailutils''
| style="border-style: solid; border-width: 1px"|version
| style="border-style: solid; border-width: 1px"|Mailutils version number
| style="border-style: solid; border-width: 1px"|status
| style="border-style: solid; border-width: 1px"|Session status.  One of: ''disconnected'', ''connected'' or ''logged in''.
For example:
  prompt "[${user}@$host] "
Notice the use of quotes to include the space character in the prompt.
:Exit the program.
;help [''command'']
:Without arguments displays a list of commands with possible arguments and short descriptions.
:With one argument, displays a terse description for the given ''command''.
;? [''command'']
:A synonym for <tt>help</tt>.
:Shows command history.
== imap ==
The <tt>mu imap</tt> command invokes an interactive IMAP4 client shell. It reads commands from the standard input, executes them and displays the results on the standard output. The shell is similar to the <tt>pop</tt> shell, which see.
=== IMAP protocol commands ===
Most commands in this group correspond (with minor differences) to IMAP commands described in [http://www.faqs.org/rfcs/rfc3501.html RFC 3501].
;connect [-tls] ''hostname'' [''port'']
:Open connection to ''hostname''. If the <tt>-tls</tt> option is given, TLS encryption (also known as IMAPS protocol) will be used. If port argument is not supplied, the command uses port 143 for a plain IMAP connection or 993 for IMAPS (if <tt>-tls</tt> is given).
;capability [-reread] [''name''...]
:List server capabilities.  Any number of ''name'' arguments is accepted.  If given, the shell will display only the named capabilities, otherwise it displays the entire list.  By default <tt>capability</tt> reuses the response of its previous invocation (if there was any), instead of resending the <tt>CAPABILITY</tt> command to the server.  To force it do so, use the <tt>-reread</tt> option.
:Start TLS negotiation.  This command is valid only after unencrypted connection has been successfully initiated using <tt>connect</tt> without <tt>-tls</tt> argument.
;login ''user'' [''pass'']
:Login to the server as ''user'' with password ''pass''.  If the ''pass'' argument is omitted, the shell will ask you to enter it.  While entering, both echoing and history recording will be disabled.  Use this to avoid compromising your password.
:Quit imap session
;id [-test ''kw''] [''arg'' [''arg''...]]
:Send IMAP ID command.  See [http://www.faqs.org/rfcs/rfc2971.html RFC 2971], for a discussion of arguments.  By default, this command outputs entire ID list.  If, however, the <tt>-test ''kw''</tt> option is given, it will check whether the keyword ''kw'' is defined and display its value if so.
:Request a server checkpoint.
;select [''mbox'']
:Select a mailbox.  Without argument, selects <tt>"INBOX"</tt>.
;examine [''mbox'']
:Examine a mailbox, i.e. select it in read-only mode.  If ''mbox'' is not given, <tt>"INBOX"</tt> is assumed.
;status ''mbox'' ''kw'' [''kw''...]
:Get mailbox status.  Valid keywords (''kw'') are: <tt>MESSAGES</tt>, <tt>RECENT</tt>, <tt>UIDNEXT</tt>, <tt>UIDVALIDITY</tt>, and <tt>UNSEEN</tt>.  Keywords are case-insensitive.
;fetch ''msgset'' ''items''
:Fetch message data.  See [http://tools.ietf.org/html/rfc3501#section-6.4.5 RFC 3501, section 6.4.5], for a discussion of its arguments.
;store ''msgset'' ''items''
:Alter mailbox data.  See [http://tools.ietf.org/html/rfc3501#section-6.4.6 RFC 3501, section 6.4.6], for a discussion of its arguments.
:Close the mailbox (with expunge).
:Close the mailbox (without expunge).
;delete ''mbox''
:Delete the mailbox.
;rename ''old-name'' ''new-name''
:Rename existing mailbox ''old-name'' to ''new-name''
:Permanently remove messages marked for deletion.
;create ''mbox''
:Create new mailbox.
;append [-time ''datetime''] [-flag ''flag''] ''mailbox'' ''file''
:Read an RFC-822 message from ''file'' and append it to the ''mailbox''.  Use the <tt>-time</tt> option to supply envelope date for the message.  Use <tt>-flag</tt> option to supply message flags.  For example:
  append -time "25-Aug-2002 18:00:00 +0200" -flag \Seen INBOX input.msg
;list ''ref'' ''mbox''
:List matching mailboxes.  See [http://tools.ietf.org/html/rfc3501#section-6.3.8 RFC 3501, section 6.3.8], for a discussion of its arguments.
;lsub ''ref'' ''mbox''
:List subscribed mailboxes ([http://tools.ietf.org/html/rfc3501#section-6.3.9 RFC 3501, section 6.3.9]).
;subscribe ''mbox''
:Subscribe to a mailbox.
;unsubscribe ''mbox''
:Remove mailbox ''mbox'' from the subscription list.
:Same as <tt>logout</tt>.
:Send a ''no operation''.
:Close existing connection.
=== Internal commands ===
The <tt>imap</tt> shell implements the same set of internal commands as <tt>pop</tt> shell (see the [[#pop-internal|description above]]).  There is only one imap-specific internal command:
;uid [on|off]
:Control UID mode.  When the UID mode is <tt>on</tt>, the commands <tt>fetch</tt> and <tt>store</tt> (and, in future, <tt>search</tt> and <tt>copy</tt>) operate on and return message UIDs instead of their sequence numbers.
:To examine the current state of the UID mode, issue the <tt>uid</tt> command without arguments.

Latest revision as of 10:37, 11 July 2015