int fmtmsg(long classification, const char label, int severity, const char text, const char action, const char tag);
fmtmsg can be used instead of the traditional printf interface to display messages to stderr. fmtmsg, in conjunction with gettxt, provides a simple interface for producing language-independent applications.
A formatted message consists of up to five standard components as defined below. The component, classification, is not part of the standard message displayed to the user, but rather defines the source of the message and directs the display of the formatted message.
An additional identifier, MM_NULLMC, indicates that no classification component is supplied for the message.
Other severity levels may be added by using the addseverity routine.
MSGVERB tells fmtmsg which message components it is to select when writing messages to stderr. The value of MSGVERB is a colon-separated list of optional keywords. MSGVERB can be set as follows:
MSGVERB=[keyword[:keyword[:. . .]]] export MSGVERB
Valid keywords are: label, severity, text, action, and tag. If MSGVERB contains a keyword for a component and the component's value is not the component's null value, fmtmsg includes that component in the message when writing the message to stderr. If MSGVERB does not include a keyword for a message component, that component is not included in the display of the message. The keywords may appear in any order. If MSGVERB is not defined, if its value is the null-string, if its value is not of the correct format, or if it contains keywords other than the valid ones listed above, fmtmsg selects all components.
The first time fmtmsg is called, it examines the MSGVERB environment variable to see which message components it is to select when generating a message to write to the standard error stream, stderr. The values accepted on the initial call are saved for future calls.
MSGVERB affects only which components are selected for display to the standard error stream. All message components are included in console messages.
SEV_LEVEL defines severity levels and associates print strings with them for use by fmtmsg. The standard severity levels shown below cannot be modified. Additional severity levels can also be defined, redefined, and removed using addseverity [see addseverity(3C)]. If the same severity level is defined by both SEV_LEVEL and addseverity, the definition by addseverity is controlling.
SEV_LEVEL can be set as follows:
SEV_LEVEL=[description[:description[:...]]] export SEV_LEVEL
description is a comma-separated list containing three fields:
severity_keyword is a character string that is used as the keyword on the -s severity option to the fmtmsg command. (This field is not used by the fmtmsg function.)
level is a character string that evaluates to a positive integer (other than 0, 1, 2, 3, or 4, which are reserved for the standard severity levels). If the keyword severity_keyword is used, level is the severity value passed on to the fmtmsg function.
printstring is the character string used by fmtmsg in the standard message format whenever the severity value level is used.
If a description in the colon list is not a three-field comma list, or, if the second field of a comma list does not evaluate to a positive integer, that description in the colon list is ignored.
The first time fmtmsg is called, it examines the SEV_LEVEL environment variable, if defined, to see whether the environment expands the levels of severity beyond the five standard levels and those defined using addseverity. The values accepted on the initial call are saved for future calls.
The table below indicates the null values and identifiers for fmtmsg arguments.
Another means of systematically omitting a component is by omitting the component keyword(s) when defining the MSGVERB environment variable (see the ``Environment Variables'' section).
fmtmsg(MM_PRINT, "UX:cat", MM_ERROR, "invalid syntax", "refer to manual", "UX:cat:001")
produces a complete message in the standard message format:
UX:cat: ERROR: invalid syntax TO FIX: refer to manual UX:cat:001
When the environment variable MSGVERB is set as follows:
and the Example 1 is used, fmtmsg produces:
ERROR: invalid syntax TO FIX: refer to manual
the following call to fmtmsg:
fmtmsg(MM_UTIL | MM_PRINT, "UX:cat", 5, "invalid syntax", "refer to manual", "UX:cat:001")
UX:cat: NOTE: invalid syntax TO FIX: refer to manual UX:cat:001