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.