Direct mail is a broad term that includes the following types of mailed promotions: Institutional direct mail serves to promote the name of the publishing house with no reasonable expectation of sales revenues.
touch (Unix) touch is a standard Unix command-line interface program which is used to update the access date and / or modification date of a file or directory. In its default usage, it is the equivalent of creating or opening a file and saving it without any change to the file contents.
4.3. Shell MetacharactersÂ¶ Linux for Programmers and Users, Section 5.5. As was discussed in Structure of a Command, the command options, option arguments and command arguments are separated by the space character. However, we can also use special characters called metacharacters in a Unix command that the shell interprets rather than passing to the command. The Shell Metacharacters are listed here for reference. Many of the metacharacters are described elsewhere in the study guide.