man pages section 3: Basic Library Functions

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Updated: July 2014



pfmt - display error message in standard format


#include <pfmt.h>

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


The pfmt() 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.

The pfmt() function encapsulates the output in the standard error message format (unless MM_NOSTD is specified, in which case the output is similar to printf()).

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


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

The catalog field is used to indicate the message database that contains the localized version of the format string. This field must be limited to 14 characters selected from the set of all characters values, excluding \0 (null) 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, pfmt() will attempt to retrieve the message from the C locale. If this second retrieval fails, pfmt() uses the defmsg field of the format argument.

If catalog is omitted, pfmt() 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:


The pfmt() will output Message not found!!\n as 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 determine the type of output (such as whether the format should be interpreted as is or 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


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


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

Catalog access control


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


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

Severity (standard message format only)


Generate a localized version of HALT, but do not halt the machine.


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


Generate a localized version of WARNING.


Generate a localized version of INFO.

Additional severities can be defined. Add-on severities can be defined with number-string pairs with numeric values from the range [5-255], using addsev(3C). The specified severity will be generated from the bitwise OR operation of the numeric value and other flags If the severity is not defined, pfmt() uses the string SEV=N, where N is replaced by 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).



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



The pfmt() 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 pfmt() is called twice to display an error message and a helpful action or recovery message, the output can look like:

label: severity: textlabel: TO FIX: text

Return Values

Upon success, pfmt() returns the number of bytes transmitted. Upon failure, it returns a negative value:


Write error to stream.


Example 1 Example of pfmt() function.

Example 1:

pfmt(stderr, MM_ERROR, "test:2:Cannot open file: %s\n",

displays the message:

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

Example 2:

pfmt(stderr, MM_ERROR, ":10:Syntax error\n");
pfmt(stderr, MM_ACTION, "55:Usage ...\n");

displays the message

UX:test: ERROR: Syntax error
UX:test: TO FIX: Usage ...


Since it uses gettxt(3C), pfmt() should not be used.


See attributes(5) for descriptions of the following attributes:


See also

addsev(3C), gettxt(3C), lfmt(3C), printf(3C), setcat(3C), setlabel(3C), setlocale(3C), attributes(5), environ(5)