Updated: 2022/Sep/29
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POSTMAP(1) General Commands Manual POSTMAP(1)
NAME
postmap - Postfix lookup table management
SYNOPSIS
postmap [-bfFhimnNoprsuUvw] [-c config_dir] [-d key] [-q key]
[file_type:]file_name ...
DESCRIPTION
The postmap(1) command creates or queries one or more Postfix lookup
tables, or updates an existing one.
If the result files do not exist they will be created with the same
group and other read permissions as their source file.
While the table update is in progress, signal delivery is postponed,
and an exclusive, advisory, lock is placed on the entire table, in
order to avoid surprises in spectator processes.
INPUT FILE FORMAT
The format of a lookup table input file is as follows:
⊕ A table entry has the form
key whitespace value
⊕ Empty lines and whitespace-only lines are ignored, as are lines
whose first non-whitespace character is a `#'.
⊕ A logical line starts with non-whitespace text. A line that
starts with whitespace continues a logical line.
The key and value are processed as is, except that surrounding white
space is stripped off. Whitespace in lookup keys is supported in
Postfix 3.2 and later, by surrounding the key with double quote
characters `"'. Within the double quotes, double quote `"' and
backslash `\' characters can be included by quoting them with a
preceding backslash.
When the -F option is given, the value must specify one or more
filenames separated by comma and/or whitespace; postmap(1) will
concatenate the file content (with a newline character inserted between
files) and will store the base64-encoded result instead of the value.
When the key specifies email address information, the localpart should
be enclosed with double quotes if required by RFC 5322. For example, an
address localpart that contains ";", or a localpart that starts or ends
with ".".
By default the lookup key is mapped to lowercase to make the lookups
case insensitive; as of Postfix 2.3 this case folding happens only with
tables whose lookup keys are fixed-case strings such as btree:, dbm: or
hash:. With earlier versions, the lookup key is folded even with tables
where a lookup field can match both upper and lower case text, such as
regexp: and pcre:. This resulted in loss of information with $number
substitutions.
COMMAND-LINE ARGUMENTS
-b Enable message body query mode. When reading lookup keys from
standard input with "-q -", process the input as if it is an
email message in RFC 5322 format. Each line of body content
becomes one lookup key.
By default, the -b option starts generating lookup keys at the
first non-header line, and stops when the end of the message is
reached. To simulate body_checks(5) processing, enable MIME
parsing with -m. With this, the -b option generates no
body-style lookup keys for attachment MIME headers and for
attached message/* headers.
NOTE: with "smtputf8_enable = yes", the -b option disables UTF-8
syntax checks on query keys and lookup results. Specify the -U
option to force UTF-8 syntax checks anyway.
This feature is available in Postfix version 2.6 and later.
-c config_dir
Read the main.cf configuration file in the named directory
instead of the default configuration directory.
-d key Search the specified maps for key and remove one entry per map.
The exit status is zero when the requested information was
found.
If a key value of - is specified, the program reads key values
from the standard input stream. The exit status is zero when at
least one of the requested keys was found.
-f Do not fold the lookup key to lower case while creating or
querying a table.
With Postfix version 2.3 and later, this option has no effect
for regular expression tables. There, case folding is controlled
by appending a flag to a pattern.
-F When querying a map, or listing a map, base64-decode each value.
When creating a map from source file, process each value as a
list of filenames, concatenate the content of those files, and
store the base64-encoded result instead of the value (see INPUT
FILE FORMAT for details).
This feature is available in Postfix version 3.4 and later.
-h Enable message header query mode. When reading lookup keys from
standard input with "-q -", process the input as if it is an
email message in RFC 5322 format. Each logical header line
becomes one lookup key. A multi-line header becomes one lookup
key with one or more embedded newline characters.
By default, the -h option generates lookup keys until the first
non-header line is reached. To simulate header_checks(5)
processing, enable MIME parsing with -m. With this, the -h
option also generates header-style lookup keys for attachment
MIME headers and for attached message/* headers.
NOTE: with "smtputf8_enable = yes", the -b option option
disables UTF-8 syntax checks on query keys and lookup results.
Specify the -U option to force UTF-8 syntax checks anyway.
This feature is available in Postfix version 2.6 and later.
-i Incremental mode. Read entries from standard input and do not
truncate an existing database. By default, postmap(1) creates a
new database from the entries in file_name.
-m Enable MIME parsing with "-b" and "-h".
This feature is available in Postfix version 2.6 and later.
-N Include the terminating null character that terminates lookup
keys and values. By default, postmap(1) does whatever is the
default for the host operating system.
-n Don't include the terminating null character that terminates
lookup keys and values. By default, postmap(1) does whatever is
the default for the host operating system.
-o Do not release root privileges when processing a non-root input
file. By default, postmap(1) drops root privileges and runs as
the source file owner instead.
-p Do not inherit the file access permissions from the input file
when creating a new file. Instead, create a new file with
default access permissions (mode 0644).
-q key Search the specified maps for key and write the first value
found to the standard output stream. The exit status is zero
when the requested information was found.
Note: this performs a single query with the key as specified,
and does not make iterative queries with substrings of the key
as described for access(5), canonical(5), transport(5),
virtual(5) and other Postfix table-driven features.
If a key value of - is specified, the program reads key values
from the standard input stream and writes one line of key value
output for each key that was found. The exit status is zero when
at least one of the requested keys was found.
-r When updating a table, do not complain about attempts to update
existing entries, and make those updates anyway.
-s Retrieve all database elements, and write one line of key value
output for each element. The elements are printed in database
order, which is not necessarily the same as the original input
order.
This feature is available in Postfix version 2.2 and later, and
is not available for all database types.
-u Disable UTF-8 support. UTF-8 support is enabled by default when
"smtputf8_enable = yes". It requires that keys and values are
valid UTF-8 strings.
-U With "smtputf8_enable = yes", force UTF-8 syntax checks with the
-b and -h options.
-v Enable verbose logging for debugging purposes. Multiple -v
options make the software increasingly verbose.
-w When updating a table, do not complain about attempts to update
existing entries, and ignore those attempts.
Arguments:
file_type
The database type. To find out what types are supported, use the
"postconf -m" command.
The postmap(1) command can query any supported file type, but it
can create only the following file types:
btree The output file is a btree file, named file_name.db.
This is available on systems with support for db
databases.
cdb The output consists of one file, named file_name.cdb.
This is available on systems with support for cdb
databases.
dbm The output consists of two files, named file_name.pag and
file_name.dir. This is available on systems with support
for dbm databases.
fail A table that reliably fails all requests. The lookup
table name is used for logging only. This table exists to
simplify Postfix error tests.
hash The output file is a hashed file, named file_name.db.
This is available on systems with support for db
databases.
lmdb The output is a btree-based file, named file_name.lmdb.
lmdb supports concurrent writes and reads from different
processes, unlike other supported file-based tables.
This is available on systems with support for lmdb
databases.
sdbm The output consists of two files, named file_name.pag and
file_name.dir. This is available on systems with support
for sdbm databases.
When no file_type is specified, the software uses the database
type specified via the default_database_type configuration
parameter.
file_name
The name of the lookup table source file when rebuilding a
database.
DIAGNOSTICS
Problems are logged to the standard error stream and to syslogd(8) or
postlogd(8). No output means that no problems were detected. Duplicate
entries are skipped and are flagged with a warning.
postmap(1) terminates with zero exit status in case of success
(including successful "postmap -q" lookup) and terminates with non-zero
exit status in case of failure.
ENVIRONMENT
MAIL_CONFIG
Directory with Postfix configuration files.
MAIL_VERBOSE
Enable verbose logging for debugging purposes.
CONFIGURATION PARAMETERS
The following main.cf parameters are especially relevant to this
program. The text below provides only a parameter summary. See
postconf(5) for more details including examples.
berkeley_db_create_buffer_size (16777216)
The per-table I/O buffer size for programs that create Berkeley
DB hash or btree tables.
berkeley_db_read_buffer_size (131072)
The per-table I/O buffer size for programs that read Berkeley DB
hash or btree tables.
config_directory (see 'postconf -d' output)
The default location of the Postfix main.cf and master.cf
configuration files.
default_database_type (see 'postconf -d' output)
The default database type for use in newaliases(1), postalias(1)
and postmap(1) commands.
import_environment (see 'postconf -d' output)
The list of environment variables that a privileged Postfix
process will import from a non-Postfix parent process, or
name=value environment overrides.
smtputf8_enable (yes)
Enable preliminary SMTPUTF8 support for the protocols described
in RFC 6531, RFC 6532, and RFC 6533.
syslog_facility (mail)
The syslog facility of Postfix logging.
syslog_name (see 'postconf -d' output)
A prefix that is prepended to the process name in syslog
records, so that, for example, "smtpd" becomes "prefix/smtpd".
Available in Postfix 2.11 and later:
lmdb_map_size (16777216)
The initial OpenLDAP LMDB database size limit in bytes.
SEE ALSO
postalias(1), create/update/query alias database
postconf(1), supported database types
postconf(5), configuration parameters
postlogd(8), Postfix logging
syslogd(8), system logging
README FILES
Use "postconf readme_directory" or "postconf html_directory" to locate
this information.
DATABASE_README, Postfix lookup table overview
LICENSE
The Secure Mailer license must be distributed with this software.
AUTHOR(S)
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
POSTMAP(1)