Tribblix: manual page: lfmt.3c

LFMT(3C) Standard C Library Functions LFMT(3C)

NAME

lfmt - display error message in standard format and pass to logging
and monitoring services

SYNOPSIS

#include <pfmt.h>

int lfmt(FILE *stream, long flags, char *format, ... /* arg*/);

DESCRIPTION

The lfmt() function retrieves a format string from a locale-specific
message database (unless MM_NOGET is specified) and uses it for
printf(3C) style formatting of args. The output is displayed on
stream. If stream is NULL no output is displayed.

The lfmt() function encapsulates the output in the standard error
message format (unless MM_NOSTD is specified, in which case the
output is like that of printf(). It forwards its output to the
logging and monitoring facility, even if stream is NULL. Optionally,
lfmt() displays the output on the console with a date and time stamp.

If the printf() format string is to be retrieved from a message
database, the format argument must have the following structure:

<catalog>:<msgnum>:<defmsg>.

If MM_NOGET is specified, only the <defmsg> field must be
specified.

The <catalog> field indicates the message database that contains the
localized version of the format string. This field is limited to 14
characters selected from a set of all characters values, excluding
the null character (\0) and the ASCII codes for slash (/) and colon
(:).

The <msgnum> field is a positive number that indicates the index of
the string into the message database.

If the catalog does not exist in the locale (specified by the last
call to setlocale(3C) using the LC_ALL or LC_MESSAGES categories),
or if the message number is out of bound, lfmt() will attempt to
retrieve the message from the C locale. If this second retrieval
fails, lfmt() uses the <defmsg> field of the format argument.

If <catalog> is omitted, lfmt() will attempt to retrieve the string
from the default catalog specified by the last call to setcat(3C). In
this case, the format argument has the following structure:

:<msgnum>:<defmsg>.

The lfmt() function will output the message

Message not found!!\n

as the format string if <catalog> is not a valid catalog name, if no
catalog is specified (either explicitly or with setcat()), if
<msgnum> is not a valid number, or if no message could be retrieved
from the message databases and <defmsg> was omitted.

The flags argument determines the type of output (whether the format
should be interpreted as it is or be encapsulated in the standard
message format) and the access to message catalogs to retrieve a
localized version of format.

The flags argument is composed of several groups, and can take the
following values (one from each group):

Output format control

MM_NOSTD
Do not use the standard message format but interpret
format as a printf() format. Only catalog access
control flags, console display control and logging
information should be specified if MM_NOSTD is used;
all other flags will be ignored.

MM_STD
Output using the standard message format (default
value is 0).

Catalog access control

MM_NOGET
Do not retrieve a localized version of format. In
this case, only the <defmsg> field of format is
specified.

MM_GET
Retrieve a localized version of format from
<catalog>, using <msgid> as the index and <defmsg> as
the default message (default value is 0).

Severity (standard message format only)

MM_HALT
Generate a localized version of HALT, but donot
halt the machine.

MM_ERROR
Generate a localized version of ERROR (default
value is 0).

MM_WARNING
Generate a localized version of WARNING.

MM_INFO
Generate a localized version of INFO.

Additional severities can be defined with the addsev(3C)
function, using number-string pairs with numeric values in the
range [5-255]. The specified severity is formed by the bitwise OR
operation of the numeric value and other flags arguments.

If the severity is not defined, lfmt() uses the string SEV=N
where N is the integer severity value passed in flags.

Multiple severities passed in flags will not be detected as an
error. Any combination of severities will be summed and the
numeric value will cause the display of either a severity string
(if defined) or the string SEV=N (if undefined).

Action

MM_ACTION
Specify an action message. Any severity value is
superseded and replaced by a localized version of TO
FIX.

Console display control

MM_CONSOLE
Display the message to the console in addition to
the specified stream.

MM_NOCONSOLE
Do not display the message to the console in
addition to the specified stream (default value
is 0).

Logging information

Major classification

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

Message source subclassification

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

STANDARD ERROR MESSAGE FORMAT

The lfmt() function displays error messages in the following format:

label: severity: text

If no label was defined by a call to setlabel(3C), the message is
displayed in the format:

severity: text

If lfmt() is called twice to display an error message and a helpful
action or recovery message, the output may appear as follows:

label: severity: text
label: TO FIX: text

RETURN VALUES

Upon successful completion, lfmt() returns the number of bytes
transmitted. Otherwise, it returns a negative value:

-1
Write the error to stream.

-2
Cannot log and/or display at console.

USAGE

Since lfmt() uses gettxt(3C), it is recommended that lfmt() not be
used.

EXAMPLES

Example 1: The following example

setlabel("UX:test");
lfmt(stderr, MM_ERROR|MM_CONSOLE|MM_SOFT|MM_UTIL,
"test:2:Cannot open file: %s\n", strerror(errno));

displays the message to stderr and to the console and makes it
available for logging:

UX:test: ERROR: Cannot open file: No such file or directory

Example 2: The following example

setlabel("UX:test");
lfmt(stderr, MM_INFO|MM_SOFT|MM_UTIL,
"test:23:test facility is enabled\n");

displays the message to stderr and makes it available for logging:

UX:test: INFO: test facility enabled

ATTRIBUTES