The on-line documentation which provides further information about the condition and the message, such as “
fmtmsg(3)”. The character string is not limited to a specific size.
If no
tag is to be supplied,
MM_NOTAG must be specified.
Further effect on the formatting of the message as displayed on the standard error stream (but not on the system console!) may be taken by setting the
MSGVERB environment variable, which selects the subset of message components to be printed. It consists of a colon-separated list of the optional keywords
label,
severity,
text,
action, and
tag, which correspond to the arguments to
fmtmsg() with the same names. If
MSGVERB is either not set or malformed (containing empty or unknown keywords), its content is ignored an all message components will be selected.
Note that displaying a message on the system console may fail due to inappropriate privileges or a non-permissive file mode of the console device.