1 /* $NetBSD: subr_prf.c,v 1.9 2003/04/27 11:12:14 tron 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)printf.c 8.1 (Berkeley) 6/11/93 36 */ 37 38 /* 39 * Scaled down version of printf(3). 40 */ 41 42 #include <sys/cdefs.h> 43 #include <sys/types.h> 44 #include <machine/stdarg.h> 45 46 #include "stand.h" 47 48 static void kprintn(void (*)(int), u_long, int); 49 static void sputchar(int); 50 static void kdoprnt(void (*)(int), const char *, va_list); 51 52 static char *sbuf, *ebuf; 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: switch (ch = *fmt++) { 96 case 'l': 97 lflag = 1; 98 goto reswitch; 99 case 'c': 100 ch = va_arg(ap, int); 101 put(ch & 0x7f); 102 break; 103 case 's': 104 p = va_arg(ap, char *); 105 while ((ch = *p++)) 106 put(ch); 107 break; 108 case 'd': 109 ul = lflag ? 110 va_arg(ap, long) : va_arg(ap, int); 111 if ((long)ul < 0) { 112 put('-'); 113 ul = -(long)ul; 114 } 115 kprintn(put, ul, 10); 116 break; 117 case 'o': 118 ul = lflag ? 119 va_arg(ap, u_long) : va_arg(ap, u_int); 120 kprintn(put, ul, 8); 121 break; 122 case 'u': 123 ul = lflag ? 124 va_arg(ap, u_long) : va_arg(ap, u_int); 125 kprintn(put, ul, 10); 126 break; 127 case 'p': 128 put('0'); 129 put('x'); 130 lflag = 1; 131 /* fall through */ 132 case 'x': 133 ul = lflag ? 134 va_arg(ap, u_long) : va_arg(ap, u_int); 135 kprintn(put, ul, 16); 136 break; 137 default: 138 put('%'); 139 if (lflag) 140 put('l'); 141 if (ch == '\0') 142 return; 143 put(ch); 144 } 145 } 146 } 147 148 static void 149 kprintn(void (*put)(int), unsigned long ul, int base) 150 { 151 /* hold a long in base 8 */ 152 char *p, buf[(sizeof(long) * NBBY / 3) + 1]; 153 154 p = buf; 155 do { 156 *p++ = "0123456789abcdef"[ul % base]; 157 } while (ul /= base); 158 do { 159 put(*--p); 160 } while (p > buf); 161 } 162