postalias Man page

POSTALIAS(1) General Commands Manual POSTALIAS(1)

NAME

postalias – Postfix alias database maintenance

SYNOPSIS

postalias [-Nfinoprsuvw] [-c config_dir] [-d key] [-q key] [file_type:]file_name …

DESCRIPTION

The postalias command creates or queries one or more Postfix alias
databases, or updates an existing one. The input and output file for‐
mats 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 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 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 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 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.

-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.

-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 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.

fail A table that reliably fails all requests. The lookup ta‐
ble name is used for logging only. This table exists to
simplify Postfix error tests.

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 data‐
base.

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.

postalias terminates with zero exit status in case of success
(including successful “postalias -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 pro‐
gram.

The text below provides only a parameter summary. See postconf(5) for
more details including examples.

alias_database (see ‘postconf -d’ output)
The alias databases for local(8) delivery that are updated with
“newaliases” or with “sendmail -bi”.

config_directory (see ‘postconf -d’ output)
The default location of the Postfix main.cf and master.cf con‐
figuration files.

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.

default_database_type (see ‘postconf -d’ output)
The default database type for use in newaliases, postalias
and postmap commands.

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)
The mail system name that is prepended to the process name in
syslog records, so that “smtpd” becomes, for example, “post‐
fix/smtpd”.

STANDARDS
RFC 822 (ARPA Internet Text Messages)

SEE ALSO

aliases(5), format of alias database input file.
local(8), Postfix local delivery agent.
postconf, supported database types
postconf(5), configuration parameters
postmap, create/update/query lookup tables
newaliases, Sendmail compatibility interface.
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

POSTALIAS(1)