POSTMAP(1) General Commands Manual POSTMAP(1)
📛 NAME
postmap - Postfix lookup table management
🚀 Quick Reference
| Use Case | Command | Description |
|---|
| Create/Update map | postmap file_name | Create or update a Postfix lookup table from a source file. |
| Query map | postmap -q key file_type:file_name | Search a map for a key and print the value. |
| Delete key | postmap -d key file_type:file_name | Search a map for a key and remove the entry. |
| List all | postmap -s file_type:file_name | Retrieve all database elements. |
| Incremental update | postmap -i file_type:file_name | Read entries from stdin and do not truncate existing database. |
| Verbose logging | postmap -v file_name | Enable verbose logging for debugging. |
📋 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 as of Postfix 3.2.
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 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 FORMAT for details).
- -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 parameters 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..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".
- lmdb_map_size (16777216) The initial OpenLDAP LMDB database size limit in bytes. (Available in Postfix 2.11 and later)
📚 SEE ALSO
📖 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
