- Unix Commands Reference
- Unix - Tutorial Home
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
postalias - Unix, Linux Command
NAMEpostalias - Postfix alias database maintenance
DESCRIPTIONThe 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 the 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 programs.
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.
|-c config_dir||Read the main.cf configuration file in the named directory instead of the default configuration directory.|
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, 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||Dont 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).|
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.|
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:
|file_name||The name of the alias database source file when creating a database.|
DIAGNOSTICSProblems 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(1) 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.
|MAIL_CONFIG||Directory with Postfix configuration files.|
|MAIL_VERBOSE||Enable verbose logging for debugging purposes.|
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 configuration 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(1), postalias(1) and postmap(1) commands.|
|syslog_facility (mail)||The syslog facility of Postfix logging.|
|syslog_name (postfix)||The mail system name that is prepended to the process name in syslog records, so that "smtpd" becomes, for example, "postfix/smtpd".|
RFC 822 (ARPA Internet Text Messages)
aliases(5), format of alias database input file. local(8), Postfix local delivery agent. postconf(1), supported database types postconf(5), configuration parameters postmap(1), create/update/query lookup tables newaliases(1), Sendmail compatibility interface. syslogd(8), system logging
DATABASE_README, Postfix lookup table overview
Wietse Venema IBM T.J. Watson Research P.O. Box 704 Yorktown Heights, NY 10598, USA