1printf(3UCB) SunOS/BSD Compatibility Library Functions printf(3UCB)
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6 printf, fprintf, sprintf, vprintf, vfprintf, vsprintf - formatted out‐
7 put conversion
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10 /usr/ucb/cc [flag ...] file ...
11 #include <stdio.h>
12 int printf(format, ...)
14 const char *format;
15 int fprintf(stream, format, va_list)
18 FILE *stream;
19 char *format;
20 va_dcl;
21 char *sprintf(s, format, va_list)
24 char *s, *format;
25 va_dcl;
26 int vprintf(format, ap)
29 char *format;
30 va_list ap;
31 int vfprintf(stream, format, ap)
34 FILE *stream;
35 char *format;
36 va_list ap;
37 char *vsprintf(s, format, ap)
40 char *s, *format;
41 va_list ap;
42
45 printf() places output on the standard output stream stdout. fprintf()
46 places output on the named output stream. sprintf() places "output,"
47 followed by the NULL character (\0), in consecutive bytes starting at
48 *s; it is the user's responsibility to ensure that enough storage is
49 available.
50 vprintf(), vfprintf(), and vsprintf() are the same as printf(),
53 fprintf(), and sprintf() respectively, except that instead of being
54 called with a variable number of arguments, they are called with an
55 argument list as defined by <varargs.h>.
56 Each of these functions converts, formats, and prints its args under
59 control of the format. The format is a character string which contains
60 two types of objects: plain characters, which are simply copied to the
61 output stream, and conversion specifications, each of which causes con‐
62 version and printing of zero or more args. The results are undefined if
63 there are insufficient args for the format. If the format is exhausted
64 while args remain, the excess args are simply ignored.
65 Each conversion specification is introduced by the character %. After
68 the %, the following appear in sequence:
69 o Zero or more flags, which modify the meaning of the conver‐
71 sion specification.
72 o An optional decimal digit string specifying a minimum field
74 width. If the converted value has fewer characters than the
75 field width, it will be padded on the left (or right, if the
76 left-adjustment flag `−', described below, has been given)
77 to the field width. The padding is with blanks unless the
78 field width digit string starts with a zero, in which case
79 the padding is with zeros.
80 o A precision that gives the minimum number of digits to
82 appear for the d, i, o, u, x, or X conversions, the number
83 of digits to appear after the decimal point for the e, E,
84 and f conversions, the maximum number of significant digits
85 for the g and G conversion, or the maximum number of charac‐
86 ters to be printed from a string in s conversion. The preci‐
87 sion takes the form of a period (.) followed by a decimal
88 digit string; a NULL digit string is treated as zero. Pad‐
89 ding specified by the precision overrides the padding speci‐
90 fied by the field width.
91 o An optional l (ell) specifying that a following d, i, o, u,
93 x, or X conversion character applies to a long integer arg.
94 An l before any other conversion character is ignored.
95 o A character that indicates the type of conversion to be
97 applied.
98 A field width or precision or both may be indicated by an asterisk (*)
101 instead of a digit string. In this case, an integer arg supplies the
102 field width or precision. The arg that is actually converted is not
103 fetched until the conversion letter is seen, so the args specifying
104 field width or precision must appear before the arg (if any) to be con‐
105 verted. A negative field width argument is taken as a `−' flag followed
106 by a positive field width. If the precision argument is negative, it
107 will be changed to zero.
108 The flag characters and their meanings are:
111 − The result of the conversion will be left-justified within the
113 field.
114 + The result of a signed conversion will always begin with a
117 sign (+ or −).
118 blank If the first character of a signed conversion is not a sign, a
121 blank will be prefixed to the result. This implies that if the
122 blank and + flags both appear, the blank flag will be ignored.
123 # This flag specifies that the value is to be converted to an
126 "alternate form." For c, d, i, s, and u conversions, the flag
127 has no effect. For o conversion, it increases the precision to
128 force the first digit of the result to be a zero. For x or X
129 conversion, a non-zero result will have 0x or 0X prefixed to
130 it. For e, E, f, g, and G conversions, the result will always
131 contain a decimal point, even if no digits follow the point
132 (normally, a decimal point appears in the result of these con‐
133 versions only if a digit follows it). For g and G conversions,
134 trailing zeroes will not be removed from the result (which
135 they normally are).
136 The conversion characters and their meanings are:
140 d,i,o,u,x,X The integer arg is converted to signed decimal (d or i),
142 unsigned octal (o), unsigned decimal (u), or unsigned
143 hexadecimal notation (x and X), respectively; the let‐
144 ters abcdef are used for x conversion and the letters
145 ABCDEF for X conversion. The precision specifies the
146 minimum number of digits to appear; if the value being
147 converted can be represented in fewer digits, it will be
148 expanded with leading zeroes. (For compatibility with
149 older versions, padding with leading zeroes may alterna‐
150 tively be specified by prepending a zero to the field
151 width. This does not imply an octal value for the field
152 width.) The default precision is 1. The result of con‐
153 verting a zero value with a precision of zero is a NULL
154 string.
155 f The float or double arg is converted to decimal notation
158 in the style [−]ddd.ddd where the number of digits after
159 the decimal point is equal to the precision specifica‐
160 tion. If the precision is missing, 6 digits are given;
161 if the precision is explicitly 0, no digits and no deci‐
162 mal point are printed.
163 e,E The float or double arg is converted in the style
166 [−]d.ddde±ddd, where there is one digit before the deci‐
167 mal point and the number of digits after it is equal to
168 the precision; when the precision is missing, 6 digits
169 are produced; if the precision is zero, no decimal point
170 appears. The E format code will produce a number with E
171 instead of e introducing the exponent. The exponent
172 always contains at least two digits.
173 g,G The float or double arg is printed in style f or e (or
176 in style E in the case of a G format code), with the
177 precision specifying the number of significant digits.
178 The style used depends on the value converted: style e
179 or E will be used only if the exponent resulting from
180 the conversion is less than −4 or greater than the pre‐
181 cision. Trailing zeroes are removed from the result; a
182 decimal point appears only if it is followed by a digit.
183 The e, E f, g, and G formats print IEEE indeterminate values (infinity
187 or not-a-number) as "Infinity" or "NaN" respectively.
188 c The character arg is printed.
190 s The arg is taken to be a string (character pointer) and characters
193 from the string are printed until a NULL character (\0) is encoun‐
194 tered or until the number of characters indicated by the precision
195 specification is reached. If the precision is missing, it is taken
196 to be infinite, so all characters up to the first NULL character
197 are printed. A NULL value for arg will yield undefined results.
198 % Print a %; no argument is converted.
201 In no case does a nonexistent or small field width cause truncation of
205 a field; if the result of a conversion is wider than the field width,
206 the field is simply expanded to contain the conversion result. Padding
207 takes place only if the specified field width exceeds the actual width.
208 Characters generated by printf() and fprintf() are printed as if
209 putc(3C) had been called.
210
212 Upon success, printf() and fprintf() return the number of characters
213 transmitted, excluding the null character. vprintf() and vfprintf()
214 return the number of characters transmitted. sprintf() and vsprintf()
215 always return s. If an output error is encountered, printf(), fprint(),
216 vprintf(), and vfprintf() return EOF.
217
219 Example 1 Examples of the printf Command To Print a Date and Time
220 To print a date and time in the form "Sunday, July 3, 10:02," where
223 weekday and month are pointers to NULL-terminated strings:
224 printf("%s, %s %i, %d:%.2d", weekday, month, day, hour, min);
227 Example 2 Examples of the printf Command To Print to Five Decimal
230 Places
231 To print to five decimal places:
234 printf("pi = %.5f", 4 * atan(1. 0));
237
240 econvert(3C), putc(3C), scanf(3C), vprintf(3C)
241
243 Use of these interfaces should be restricted to only applications writ‐
244 ten on BSD platforms. Use of these interfaces with any of the system
245 libraries or in multi-thread applications is unsupported.
246 Very wide fields (>128 characters) fail.
249SunOS 5.11 30 Oct 2007 printf(3UCB)