File tagging in Enhanced ASCII

Enhanced ASCII provides support for file tagging. File tags are used to identify the code set of text data within files. When Enhanced ASCII functionality is enabled, z/OS UNIX needs to know whether files are encoded as ASCII or EBCDIC. The file tag provides this data. If no file tag exists on a particular file, that file is treated as an EBCDIC file. Setting a file tag does not force automatic code set conversion but allows it to take place when automatic code set conversion is enabled. For additional information on automatic code set conversion, see Automatic code set conversion.

Note: An entire file system can be mounted such that untagged files and new files created within the file system are treated as tagged while the mount option is in effect.

z/OS® utilities provide options to manage tags on UNIX files. The chtag command allows you to set, modify, remove, or display information in a file tag. In this example:

chtag -t -c ISO8859-1 christmas.songs

the file christmas.songs is tagged as an ASCII file. ISO8859–1 is the code set for ASCII. In this example:

chtag -t -c IBM-1047 christmas.recipes

the file christmas.recipes is tagged as an EBCDIC file. IBM-1047 is the code set for EBCDIC.

The ls command with option -T and the command chtag -p display information about the file text and codeset tags. For more information about the chtag and ls commands, see z/OS UNIX System Services Command Reference.