1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 28 /* All Rights Reserved */ 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 #include "lint.h" 33 #include <mtlib.h> 34 #include <stdarg.h> 35 #include <values.h> 36 #include <thread.h> 37 #include <synch.h> 38 #include <errno.h> 39 #include <sys/types.h> 40 #include "print.h" 41 #include "libc.h" 42 43 /*VARARGS2*/ 44 int 45 snprintf(char *string, size_t n, const char *format, ...) 46 { 47 ssize_t count; 48 FILE siop; 49 va_list ap; 50 size_t max = MAXINT; 51 unsigned char tmpbuf[1]; /* dummy buffer for _doprnt() if NULL string */ 52 53 siop._cnt = n - 1; 54 siop._base = siop._ptr = (unsigned char *)string; 55 siop._flag = _IOREAD; /* distinguish dummy file descriptor */ 56 #ifdef _LP64 57 /* 58 * _bufend() (_realbufend()) should return NULL for v/snprintf, 59 * so PUT() macro in _doprnt() will bounds check. For 32-bit, 60 * there is no _end field, and _realbufend() will return NULL 61 * since it cannot find the dummy FILE structure in the linked 62 * list of FILE strucutres. See bug 4274368. 63 */ 64 siop._end = NULL; 65 #endif /* _LP64 */ 66 67 if (n == 0) { 68 /* 69 * When n==0, string may be NULL, so always use tmpbuf to 70 * guard for this case. No bytes should be transmitted to 71 * the buffer when n==0, so using tmpbuf instead of string 72 * (ie, if string is not NULL) should not matter. 73 */ 74 siop._base = siop._ptr = tmpbuf; 75 siop._cnt = 0; 76 } else if (n > max) { 77 errno = EOVERFLOW; 78 return (EOF); 79 } 80 81 va_start(ap, format); 82 count = _ndoprnt(format, ap, &siop, 0); 83 va_end(ap); 84 85 *siop._ptr = '\0'; /* plant terminating null character */ 86 87 if (count == EOF) 88 return (EOF); 89 90 /* overflow check */ 91 if ((size_t)count > max) { 92 errno = EOVERFLOW; 93 return (EOF); 94 } else { 95 return ((int)count); 96 } 97 } 98 99 #ifndef _LP64 100 101 /* 102 * 32-bit shadow function of snprintf(). 103 * When using the c89 compiler to build 32-bit applications, the size 104 * of intmax_t is 32-bits, otherwise the size of intmax_t is 64-bits. 105 * The shadow function uses 32-bit size of intmax_t for %j conversion. 106 * The #pragma redefine_extname in <stdio.h> selects the proper routine 107 * at compile time for the user application. 108 * NOTE: this function is only available in the 32-bit library. 109 */ 110 111 int 112 _snprintf_c89(char *string, size_t n, const char *format, ...) 113 { 114 ssize_t count; 115 va_list ap; 116 117 va_start(ap, format); 118 count = _vsnprintf_c89(string, n, format, ap); 119 va_end(ap); 120 return ((int)count); 121 } 122 123 #endif /* _LP64 */ 124