vprintf(3X)                                           vprintf(3X)



     NAME
          vprintf, vfprintf, vsprintf - print formatted output of a
          varargs argument list

     SYNOPSIS
          #include <stdio.h>
          #include <varargs.h>

          int vprintf (format, ap)
          char *format;
          valist ap;

          int vfprintf (stream, format, ap)
          FILE *stream;
          char *format;
          valist ap;

          int vsprintf (s, format, ap)
          char *s, *format;
          valist ap;

     DESCRIPTION
          vprintf, vfprintf, and vsprintf are the same as printf,
          fprintf, and sprintf respectively, except that instead of
          being called with a variable number of arguments, they are
          called with an argument list as defined by varargs(5).

     EXAMPLE
          The following demonstrates how vfprintf could be used to
          write an error routine.

          #include <stdio.h>
          #include <varargs.h>
               .
               .
               .
          /*
          /*   error should be called like
          /*     error(function_name, format, arg1, arg2...);
          /*/
          /*VARARGS0*/
          void
          error(va_alist)
          /* Note that the function_name and format arguments
          /* cannot be separately declared because of the
                 definition of varargs.
          va_dcl
          {
             va_list args;
             char *fmt;

             va_start(args);



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     vprintf(3X)                                           vprintf(3X)



             /* print out name of function causing error */
             (void)fprintf(stderr, "ERROR in %s: ",
                                   va_arg(args, char *));
             fmt = va_arg(args, char *);
             /* print out remainder of message */
             (void)vfprintf(fmt, args);
             va_end(args);
             (void)abort( );
          }

     SEE ALSO
          printf(3S), varargs(5).











































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