NAME    [Toc]    [Back]

       vprintf, vfprintf, vsnprintf, vsprintf - Format a variable
       number of parameters for output

SYNOPSIS    [Toc]    [Back]

       #include <stdarg.h> #include <stdio.h>

       int vprintf(
               const char *format,
               va_list printarg ); int vfprintf(
               FILE *stream,
               const char *format,
               va_list printarg ); int vsnprintf(
               char *string,
               size_t n,
               const char *format,
               va_list printarg ); int vsprintf(
               char *string,
               const char *format,
               va_list printarg );

LIBRARY    [Toc]    [Back]

       Standard C Library (libc)

STANDARDS    [Toc]    [Back]

       Interfaces documented on this reference  page  conform  to
       industry standards as follows:

       vfprintf(),  vprintf(),  vsnprintf(),  vsprintf():  ISO C,
       XPG4, XPG4-UNIX

       Refer to the standards(5) reference page for more information
 about industry standards and associated tags.

PARAMETERS    [Toc]    [Back]

       Specifies  a  character  string that contains two types of
       objects: Plain characters, which are copied to the  output
       stream.   Conversion  specifications, each of which causes
       zero or more items to be fetched from the stdarg parameter
       lists.   Specifies the arguments to be printed.  Specifies
       the output stream.  Specifies the buffer to  which  output
       is  printed.  Specifies the size of the buffer referred to
       by string.

DESCRIPTION    [Toc]    [Back]

       The vprintf(),  vfprintf(),  vsnprintf(),  and  vsprintf()
       functions format and write stdarg parameter lists.

       These  functions  are the same as the printf(), fprintf(),
       snprintf(), and sprintf() functions, respectively,  except
       that these functions are not called with a variable number
       of    parameters.    Instead,    vprintf(),    vfprintf(),
       vsnprintf(),  and  vsprintf()  are called with a parameter
       list pointer as defined by stdarg. Because these functions
       invoke  the va_arg() macro and not the va_end() macro, the
       value of printarg is indeterminate after a return.  Therefore,
  applications  should execute a call to the va_end()
       macro after a call to one of these functions.

EXAMPLES    [Toc]    [Back]

       The following  example  demonstrates  how  the  vfprintf()
       function can be used to write an error routine:

       #include <stdarg.h> #include <stdio.h>


       void    error(char *funct, char *fmt, ...)  {
               va_list args;
               /*
               **  Display  the  name of the function that called
       error
               */
               fprintf(stderr, "ERROR in %s: ", funct);
               /*
               ** Display the remainder of the message
               */
               va_start(args, fmt);
               vfprintf(stderr, fmt, args);
               va_end(args);
               abort(); }

SEE ALSO    [Toc]    [Back]

       Functions: fopen(3), printf(3), vwprintf(3), wprintf(3)



                                                       vprintf(3)