1 /* $NetBSD: subr_prf.c,v 1.16 2007/11/24 13:20:57 isaki Exp $ */ 2 3 /*- 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)printf.c 8.1 (Berkeley) 6/11/93 32 */ 33 34 /* 35 * Scaled down version of printf(3). 36 */ 37 38 #include <sys/cdefs.h> 39 #include <sys/types.h> 40 #include <sys/stdint.h> /* XXX: for intptr_t */ 41 #include <machine/stdarg.h> 42 43 #include "stand.h" 44 45 static void kprintn(void (*)(int), u_long, int); 46 static void sputchar(int); 47 static void kdoprnt(void (*)(int), const char *, va_list); 48 49 static char *sbuf, *ebuf; 50 51 const char HEXDIGITS[] = "0123456789ABCDEF"; 52 const char hexdigits[] = "0123456789abcdef"; 53 54 static void 55 sputchar(int c) 56 { 57 58 if (sbuf < ebuf) 59 *sbuf++ = c; 60 } 61 62 void 63 vprintf(const char *fmt, va_list ap) 64 { 65 66 kdoprnt(putchar, fmt, ap); 67 } 68 69 int 70 vsnprintf(char *buf, size_t size, const char *fmt, va_list ap) 71 { 72 73 sbuf = buf; 74 ebuf = buf + size - 1; 75 kdoprnt(sputchar, fmt, ap); 76 *sbuf = '\0'; 77 return sbuf - buf; 78 } 79 80 static void 81 kdoprnt(void (*put)(int), const char *fmt, va_list ap) 82 { 83 char *p; 84 int ch; 85 unsigned long ul; 86 int lflag; 87 88 for (;;) { 89 while ((ch = *fmt++) != '%') { 90 if (ch == '\0') 91 return; 92 put(ch); 93 } 94 lflag = 0; 95 reswitch: 96 switch (ch = *fmt++) { 97 case 'l': 98 lflag = 1; 99 goto reswitch; 100 case 't': 101 #if 0 /* XXX: abuse intptr_t until the situation with ptrdiff_t is clear */ 102 lflag = (sizeof(ptrdiff_t) == sizeof(long)); 103 #else 104 lflag = (sizeof(intptr_t) == sizeof(long)); 105 #endif 106 goto reswitch; 107 case 'z': 108 lflag = (sizeof(size_t) == sizeof(unsigned long)); 109 goto reswitch; 110 case 'c': 111 ch = va_arg(ap, int); 112 put(ch & 0x7f); 113 break; 114 case 's': 115 p = va_arg(ap, char *); 116 while ((ch = *p++)) 117 put(ch); 118 break; 119 case 'd': 120 ul = lflag ? 121 va_arg(ap, long) : va_arg(ap, int); 122 if ((long)ul < 0) { 123 put('-'); 124 ul = -(long)ul; 125 } 126 kprintn(put, ul, 10); 127 break; 128 case 'o': 129 ul = lflag ? 130 va_arg(ap, u_long) : va_arg(ap, u_int); 131 kprintn(put, ul, 8); 132 break; 133 case 'u': 134 ul = lflag ? 135 va_arg(ap, u_long) : va_arg(ap, u_int); 136 kprintn(put, ul, 10); 137 break; 138 case 'p': 139 put('0'); 140 put('x'); 141 lflag = 1; 142 /* FALLTHROUGH */ 143 case 'x': 144 ul = lflag ? 145 va_arg(ap, u_long) : va_arg(ap, u_int); 146 kprintn(put, ul, 16); 147 break; 148 default: 149 put('%'); 150 if (lflag) 151 put('l'); 152 if (ch == '\0') 153 return; 154 put(ch); 155 break; 156 } 157 } 158 } 159 160 static void 161 kprintn(void (*put)(int), unsigned long ul, int base) 162 { 163 /* hold a long in base 8 */ 164 char *p, buf[(sizeof(long) * NBBY / 3) + 1]; 165 166 p = buf; 167 do { 168 *p++ = hexdigits[ul % base]; 169 } while (ul /= base); 170 do { 171 put(*--p); 172 } while (p > buf); 173 } 174