1 /* $NetBSD: subr_prf.c,v 1.10 2003/08/07 16:32:30 agc 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 <machine/stdarg.h> 41 42 #include "stand.h" 43 44 static void kprintn(void (*)(int), u_long, int); 45 static void sputchar(int); 46 static void kdoprnt(void (*)(int), const char *, va_list); 47 48 static char *sbuf, *ebuf; 49 50 static void 51 sputchar(int c) 52 { 53 54 if (sbuf < ebuf) 55 *sbuf++ = c; 56 } 57 58 void 59 vprintf(const char *fmt, va_list ap) 60 { 61 62 kdoprnt(putchar, fmt, ap); 63 } 64 65 int 66 vsnprintf(char *buf, size_t size, const char *fmt, va_list ap) 67 { 68 69 sbuf = buf; 70 ebuf = buf + size - 1; 71 kdoprnt(sputchar, fmt, ap); 72 *sbuf = '\0'; 73 return (sbuf - buf); 74 } 75 76 static void 77 kdoprnt(void (*put)(int), const char *fmt, va_list ap) 78 { 79 char *p; 80 int ch; 81 unsigned long ul; 82 int lflag; 83 84 for (;;) { 85 while ((ch = *fmt++) != '%') { 86 if (ch == '\0') 87 return; 88 put(ch); 89 } 90 lflag = 0; 91 reswitch: switch (ch = *fmt++) { 92 case 'l': 93 lflag = 1; 94 goto reswitch; 95 case 'c': 96 ch = va_arg(ap, int); 97 put(ch & 0x7f); 98 break; 99 case 's': 100 p = va_arg(ap, char *); 101 while ((ch = *p++)) 102 put(ch); 103 break; 104 case 'd': 105 ul = lflag ? 106 va_arg(ap, long) : va_arg(ap, int); 107 if ((long)ul < 0) { 108 put('-'); 109 ul = -(long)ul; 110 } 111 kprintn(put, ul, 10); 112 break; 113 case 'o': 114 ul = lflag ? 115 va_arg(ap, u_long) : va_arg(ap, u_int); 116 kprintn(put, ul, 8); 117 break; 118 case 'u': 119 ul = lflag ? 120 va_arg(ap, u_long) : va_arg(ap, u_int); 121 kprintn(put, ul, 10); 122 break; 123 case 'p': 124 put('0'); 125 put('x'); 126 lflag = 1; 127 /* fall through */ 128 case 'x': 129 ul = lflag ? 130 va_arg(ap, u_long) : va_arg(ap, u_int); 131 kprintn(put, ul, 16); 132 break; 133 default: 134 put('%'); 135 if (lflag) 136 put('l'); 137 if (ch == '\0') 138 return; 139 put(ch); 140 } 141 } 142 } 143 144 static void 145 kprintn(void (*put)(int), unsigned long ul, int base) 146 { 147 /* hold a long in base 8 */ 148 char *p, buf[(sizeof(long) * NBBY / 3) + 1]; 149 150 p = buf; 151 do { 152 *p++ = "0123456789abcdef"[ul % base]; 153 } while (ul /= base); 154 do { 155 put(*--p); 156 } while (p > buf); 157 } 158