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FMTMSG(3)                BSD Library Functions Manual                FMTMSG(3)

NAME
     fmtmsg -- display a detailed diagnostic message

LIBRARY
     Standard C Library (libc, -lc)

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 displays a detailed diagnostic message, based on the supplied arguments, to
     stderr and/or the system console.

     The classification argument is the bitwise inclusive OR of zero or one of the manifest constants from
     each of the classification groups below.  The Output classification group is an exception since both
     MM_PRINT and MM_CONSOLE may be specified.

     Output

             MM_PRINT    Output should take place on stderr.

             MM_CONSOLE  Output should take place on the system console.

     Source of Condition (Major)

             MM_HARD     The source of the condition is hardware related.

             MM_SOFT     The source of the condition is software related.

             MM_FIRM     The source of the condition is firmware related.

     Source of Condition (Minor)

             MM_APPL     The condition was detected at the application level.

             MM_UTIL     The condition was detected at the utility level.

             MM_OPSYS    The condition was detected at the operating system level.

     Status

             MM_RECOVER  The application can recover from the condition.

             MM_NRECOV   The application is unable to recover from the condition.

     Alternatively, the MM_NULLMC manifest constant may be used to specify no classification.

     The label argument indicates the source of the message.  It is made up of two fields separated by a
     colon (`:').  The first field can be up to 10 bytes, and the second field can be up to 14 bytes.  The
     MM_NULLLBL manifest constant may be used to specify no label.

     The severity argument identifies the importance of the condition.  One of the following manifest con-stants constants
     stants should be used for this argument.

           MM_HALT     The application has confronted a serious fault and is halting.

           MM_ERROR    The application has detected a fault.

           MM_WARNING  The application has detected an unusual condition, that could be indicative of a
                       problem.

           MM_INFO     The application is providing information about a non-error condition.

           MM_NOSEV    No severity level supplied.

     The text argument details the error condition that caused the message.  There is no limit on the size
     of this character string.  The MM_NULLTXT manifest constant may be used to specify no text.

     The action argument details how the error-recovery process should begin.  Upon output, fmtmsg() will
     prefix "TO FIX:" to the beginning of the action argument.  The MM_NULLACT manifest constant may be used
     to specify no action.

     The tag argument should reference online documentation for the message.  This usually includes the
     label and a unique identifying number.  An example tag is "BSD:ls:168".  The MM_NULLTAG manifest con-stant constant
     stant may be used to specify no tag.

RETURN VALUES
     The fmtmsg() function returns MM_OK upon success, MM_NOMSG to indicate output to stderr failed,
     MM_NOCON to indicate output to the system console failed, or MM_NOTOK to indicate output to stderr and
     the system console failed.

ENVIRONMENT
     The MSGVERB (message verbosity) environment variable specifies which arguments to fmtmsg() will be out-put output
     put to stderr, and in which order.  MSGVERB should be a colon (`:') separated list of identifiers.
     Valid identifiers include: label, severity, text, action, and tag.  If invalid identifiers are speci-fied specified
     fied or incorrectly separated, the default message verbosity and ordering will be used.  The default
     ordering is equivalent to a MSGVERB with a value of "label:severity:text:action:tag".

EXAMPLES
     The code:

           fmtmsg(MM_UTIL | MM_PRINT, "BSD:ls", MM_ERROR,
               "illegal option -- z", "refer to manual", "BSD:ls:001");

     will output:

           BSD:ls: ERROR: illegal option -- z
           TO FIX: refer to manual BSD:ls:001

     to stderr.

     The same code, with MSGVERB set to "text:severity:action:tag", produces:

           illegal option -- z: ERROR
           TO FIX: refer to manual BSD:ls:001

SEE ALSO
     err(3), exit(3), strerror(3)

STANDARDS
     The fmtmsg() function conforms to IEEE Std 1003.1-2001 (``POSIX.1'').

HISTORY
     The fmtmsg() function first appeared in FreeBSD 5.0.

BUGS
     Specifying MM_NULLMC for the classification argument makes little sense, since without an output speci-fied, specified,
     fied, fmtmsg() is unable to do anything useful.

     In order for fmtmsg() to output to the system console, the effective user must have appropriate permis-sion permission
     sion to write to /dev/console.  This means that on most systems fmtmsg() will return MM_NOCON unless
     the effective user is root.

BSD                             August 5, 2002                             BSD