1vpfmt(3C) Standard C Library Functions vpfmt(3C)
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6 vpfmt - display error message in standard format and pass to logging
7 and monitoring services
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10 #include <pfmt.h>
11 #include <stdarg.h>
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13 int vpfmt(FILE *stream, long flag, const char *format, va_list ap);
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17 The vpfmt() function is identical to pfmt(3C), except that it is called
18 with an argument list as defined by <stdarg.h>.
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21 The <stdarg.h> header defines the type va_list and a set of macros for
22 advancing through a list of arguments whose number and types may vary.
23 The ap argument is of type va_list. This argument is used with the
24 <stdarg.h> macros va_start(), va_arg(), and va_end(). See stdarg(3EXT).
25 The example in the EXAMPLES section below demonstrates their use with
26 vpfmt().
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29 Upon successful completion, vpfmt() returns the number of bytes trans‐
30 mitted. Otherwise, −1 is returned if there was a write error to
31 stream.
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34 Example 1 Use of vpfmt() to write an error routine.
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37 The following example demonstrates how vpfmt() could be used to write
38 an error() routine. The va_alist() macro is used as the parameter list
39 in a function definition. The va_start(ap, ...) call, where ap is of
40 type va_list, must be invoked before any attempt to traverse and access
41 unnamed arguments. Calls to va_arg(ap, atype) traverse the argument
42 list. Each execution of va_arg() expands to an expression with the
43 value and type of the next argument in the list ap, which is the same
44 object initialized by va_start(). The atype argument is the type that
45 the returned argument is expected to be. The va_end(ap) macro must be
46 invoked when all desired arguments have been accessed. The argument
47 list in ap can be traversed again if va_start() is called again after
48 va_end(). In the example below, va_arg() is executed first to retrieve
49 the format string passed to error(). The remaining error() arguments
50 (arg1, arg2, ...) are passed to vpfmt() in the argument ap.
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53 #include <pfmt.h>
54 #include <stdarg.h>
55 /*
56 * error should be called like
57 * error(format, arg1, ...);
58 */
59 void error(...)
60 {
61 va_list ap;
62 char *format;
63 va_start(ap, );
64 format = va_arg(ap, char *);
65 (void) vpfmt(stderr, MM_ERROR, format, ap);
66 va_end(ap);
67 (void) abort();
68 }
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72 Since vpfmt() uses gettxt(3C), it is recommended that vpfmt() not be
73 used.
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76 See attributes(5) for descriptions of the following attributes:
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81 ┌─────────────────────────────┬─────────────────────────────┐
82 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
83 ├─────────────────────────────┼─────────────────────────────┤
84 │MT-Level │MT-Safe │
85 └─────────────────────────────┴─────────────────────────────┘
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88 gettxt(3C), pfmt(3C), attributes(5), stdarg(3EXT)
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92SunOS 5.11 29 Dec 1996 vpfmt(3C)