An alias file contains lines that associate an alias name with an address or group of addresses. The Message Handler (MH) package reads both personal alias files (customarily the $HOME/.mh_alias file) and a systemwide alias file, the /etc/mh/MailAliases file. Depending on the MH configuration, aliases may also be defined in the /etc/aliases file (see the sendmail command).
The alias file name is an argument to several MH commands. These commands can be set automatically by entries in the .mh_profile file. Personal alias files can have any name, but must follow the format described here. The /etc/mh/MailAliases file is the default alias file for systemwide aliases. This file is set up by a user with root user authority.
Specify your personal alias file in your .mh_profile file. Otherwise, you must use the -alias flag each time you use an MH command that requires this flag.
Each line of an .mh_alias file has one of the following formats:
The variables are described as follows:
Alias | Specifies a simple address. |
Address | Specifies a simple Internet-style address. |
Group | Specifies a group name (or number) from the /etc/group file. |
Alias-File | Specifies a system file name. The MH package treats alias file names as case-sensitive. Alias expansion is case-sensitive as well. |
The Address-Group variable can be either of the following:
AddressList | List of addresses that make up a group. |
<Alias-File | System file to be read for more alias definitions. |
The addresses in the AddressList variable must be separated by commas.
Note: If there are references to aliases within an alias definition, those aliases must be defined in a following line of the alias file.
\ (backslash) | You can continue an alias definition on the next line by ending the line to be continued with a \ (backslash) followed by a new-line character. |
< (less than) | If a line starts with a < (less-than sign), MH reads the file specified after the less-than sign for more alias definitions. The reading is done recursively.
If an address group starts with a < (less-than sign), MH reads the file specified after the less-than sign and adds the contents of that file to the address list for the alias. |
= (equal) | If an address group starts with an = (equal sign), MH consults the /etc/group file for the group specified after an equal sign. The MH package adds each login name occurring as a member of the group to the address list for the alias. |
+ (plus) | If an address group starts with a + (plus sign), MH consults the /etc/group file to determine the ID of the group. Each login name appearing in the /etc/passwd file that matches the address group is added to the address list for the alias. |
* (asterisk) | If an address group is defined by an * (asterisk), MH consults the /etc/passwd file and adds all login names with a user number greater than 200 (or the value set for everyone in the /etc/mh/mtstailor file) to the address list for the alias. |
The following list explains how the system resolves aliases at posting time:
In pattern matching, a trailing * (asterisk) in an alias matches just about anything appropriate.
The following example of an .mh_alias file illustrates some of its features:
</home/sarah/morealiases systems:= systems staff:+ staff everyone:+* manager: harold@harold project:lance,mark@remote,peter,manager
The first line says that more aliases should be read from the /home/sarah/morealiases file. The systems alias is defined as all users listed as members of the group systems in the /etc/group file. The staff alias is defined as all users whose group ID in the /etc/passwd file is equivalent to the staff group. Finally, the everyone alias is defined as all users with a user ID in the /etc/passwd file greater than 200.
The manager alias is defined as an alias for user harold@harold . The project alias is defined as the users lance , mark@remote , peter , and manager .
This file format is part of Message Handler in the Base Operating System.
/etc/aliases | Contains systemwide aliases for the sendmail command. |
/etc/group | Contains basic group attributes. |
/etc/passwd | Contains user authentication information. |
/etc/mh/MailAliases | Contains the defaults alias file for systemwide aliases, which is set up by a user with root user authority. |
/etc/mh/mtstailor | Tailors the Message Handler (MH) environment to the local environment. |
.mh_profile | Customizes the Message Handler (MH) package. |
The aliases file, /etc/group file, /etc/passwd file, $HOME/.mh_profile file.
The ali command, conflict command, post command, sendmail command, whom command.