FMTMSG(3P)						     POSIX Programmer's Manual							FMTMSG(3P)

PROLOG

       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME

       fmtmsg - display a message in the specified format on standard error and/or a system console

SYNOPSIS

       #include <fmtmsg.h>

       int fmtmsg(long classification, const char *label, int severity,
	      const char *text, const char *action, const char *tag);

DESCRIPTION

       The fmtmsg() function shall display messages in a specified format instead of the traditional printf() function.

       Based on a message's classification component, fmtmsg() shall write a formatted message either to standard error, to  the  console,  or	to
       both.

       A formatted message consists of up to five components as defined below.	The component classification is not part of a message displayed to
       the user, but defines the source of the message and directs the display of the formatted message.

       classification
	      Contains the sum of identifying values constructed from the constants defined below. Any one identifier from a subclass may be  used
	      in  combination  with  a	single identifier from a different subclass.  Two or more identifiers from the same subclass should not be
	      used together, with the exception of identifiers from the display subclass. (Both display subclass identifiers may be used  so  that
	      messages can be displayed to both standard error and the system console.)

       Major Classifications

	      Identifies the source of the condition. Identifiers are: MM_HARD (hardware), MM_SOFT (software), and MM_FIRM (firmware).

       Message Source Subclassifications

	      Identifies  the  type  of software in which the problem is detected.  Identifiers are: MM_APPL (application), MM_UTIL (utility), and
	      MM_OPSYS (operating system).

       Display Subclassifications

	      Indicates where the message is to be displayed. Identifiers are: MM_PRINT to display the	message  on  the  standard  error  stream,
	      MM_CONSOLE to display the message on the system console. One or both identifiers may be used.

       Status Subclassifications

	      Indicates  whether  the  application  can recover from the condition.  Identifiers are: MM_RECOVER (recoverable) and MM_NRECOV (non-
	      recoverable).

       An additional identifier, MM_NULLMC, indicates that no classification component is supplied for the message.

       label  Identifies the source of the message. The format is two fields separated by a colon. The first field is up to 10 bytes,  the  second
	      is up to 14 bytes.

       severity
	      Indicates the seriousness of the condition. Identifiers for the levels of severity are:

       MM_HALT
	      Indicates that the application has encountered a severe fault and is halting. Produces the string "HALT" .

       MM_ERROR
	      Indicates that the application has detected a fault. Produces the string "ERROR" .

       MM_WARNING
	      Indicates a condition that is out of the ordinary, that might be a problem, and should be watched. Produces the string "WARNING" .

       MM_INFO
	      Provides information about a condition that is not in error. Produces the string "INFO" .

       MM_NOSEV
	      Indicates that no severity level is supplied for the message.

       text   Describes  the  error  condition that produced the message. The character string is not limited to a specific size. If the character
	      string is empty, then the text produced is unspecified.

       action Describes the first step to be taken in the error-recovery process.  The fmtmsg() function precedes the action string with the  pre-
	      fix: "TO FIX:" . The action string is not limited to a specific size.

       tag    An  identifier  that  references on-line documentation for the message.  Suggested usage is that tag includes the label and a unique
	      identifying number. A sample tag is "XSI:cat:146" .

       The MSGVERB environment variable (for message verbosity) shall determine for fmtmsg() which message components it is to select when writing
       messages to standard error. The value of MSGVERB shall be a colon-separated list of optional keywords. 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()
       shall include that component in the message when writing the message to standard error. If MSGVERB does not include a keyword for a message
       component, that component shall not be 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() shall select all components.

       MSGVERB shall determine which components are selected for display to standard error. All message components shall be  included  in  console
       messages.

RETURN VALUE

       The fmtmsg() function shall return one of the following values:

       MM_OK  The function succeeded.

       MM_NOTOK
	      The function failed completely.

       MM_NOMSG
	      The function was unable to generate a message on standard error, but otherwise succeeded.

       MM_NOCON
	      The function was unable to generate a console message, but otherwise succeeded.

ERRORS

       None.

       The following sections are informative.

EXAMPLES

	1. The following example of fmtmsg():

	   fmtmsg(MM_PRINT, "XSI:cat", MM_ERROR, "illegal option",
	   "refer to cat in user's reference manual", "XSI:cat:001")

       produces a complete message in the specified message format:

	      XSI:cat: ERROR: illegal option
	      TO FIX: refer to cat in user's reference manual XSI:cat:001

	2. When the environment variable MSGVERB is set as follows:

	   MSGVERB=severity:text:action

       and Example 1 is used, fmtmsg() produces:

	      ERROR: illegal option
	      TO FIX: refer to cat in user's reference manual

APPLICATION USAGE

       One or more message components may be systematically omitted from messages generated by an application by using the null value of the argu-
       ment for that component.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       printf(), the Base Definitions volume of IEEE Std 1003.1-2001, <fmtmsg.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and  the  original  IEEE
       and  The  Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained
       online at http://www.opengroup.org/unix/online.html .

IEEE
/The Open Group						       2003								FMTMSG(3P)