vwarn(), vwarnx()

Formatted error message (varargs)

Synopsis:

#include <err.h>

void vwarn( const char *fmt, 
            va_list args );

void vwarnx( const char *fmt, 
             va_list args );

Arguments:

fmt

NULL, or a printf()-style string used to format the message.

args

A variable-argument list of the additional arguments, which you must have initialized with the va_start() macro.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The err() and warn() family of functions display a formatted error message on stderr. For a comparison of the members of this family, see err().

The vwarn() function produces a message that consists of:

• the last component of the program name, followed by a colon and a space
• the formatted message, followed by a colon and a space, if the fmt argument isn't NULL
• the string associated with the current value of errno
• a newline character.

The vwarnx() function produces a similar message, except that it doesn't include the string associated with errno. The message consists of:

• the last component of the program name, followed by a colon and a space
• the formatted message, if the fmt argument isn't NULL
• a newline character.

Classification:

Unix

See also:

err(), errx(), stderr, strerror(), verr(), verrx(), warn(), warnx()