The postalias(1) command creates or queries one or more Postfix
alias databases, or updates an existing one. The input and output
file formats are expected to be compatible with Sendmail version 8,
and are expected to be suitable for the use as NIS alias maps.
If the result files do not exist they will be created with the
same group and other read permissions as their source file.
While a database update is in progress, signal delivery is
postponed, and an exclusive, advisory, lock is placed on the
entire database, in order to avoid surprises in spectator
processes.
The format of Postfix alias input files is described in
aliases(5).
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.
Options:
-
- -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.
-
- -i
-
Incremental mode. Read entries from standard input and do not
truncate an existing database. By default, postalias(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, postalias(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, postalias(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, postalias(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 postalias(1) command can query any supported file type,
but it can create only the following file types:
-
- btree
-
The output is a btree file, named file_name.db.
This is available on systems with support for db databases.
- cdb
-
The output is 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 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.
The default value for this parameter depends on the host environment.
- file_name
-
The name of the alias database source file when creating a database.