The postmap(1) command creates or queries one or more Postfix
lookup tables, or updates an existing one. The input and output
file formats are expected to be compatible with:
makemap file_typefile_name < file_name
If the result files do not exist they will be created with the
same group and other read permissions as the 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
programs.
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. Unlike with Postfix alias
databases, quotes cannot be used to protect lookup keys that contain
special characters such as `#' or whitespace.
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
-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.
-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.
-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.
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.
-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.
hash
The output file is a hashed file, named file_name.db.
This is available on systems with support for db 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).
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.
