1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 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 32 #if 0 33 #ifndef lint 34 static char const copyright[] = 35 "@(#) Copyright (c) 1989, 1993\n\ 36 The Regents of the University of California. All rights reserved.\n"; 37 #endif /* not lint */ 38 39 #ifndef lint 40 static char sccsid[] = "@(#)echo.c 8.1 (Berkeley) 5/31/93"; 41 #endif /* not lint */ 42 #endif 43 #include <sys/cdefs.h> 44 #include <sys/types.h> 45 #include <sys/uio.h> 46 47 #include <assert.h> 48 #include <capsicum_helpers.h> 49 #include <err.h> 50 #include <errno.h> 51 #include <limits.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.h> 55 56 int 57 main(int argc, char *argv[]) 58 { 59 int nflag; /* if not set, output a trailing newline. */ 60 int veclen; /* number of writev arguments. */ 61 struct iovec *iov, *vp; /* Elements to write, current element. */ 62 char space[] = " "; 63 char newline[] = "\n"; 64 65 if (caph_limit_stdio() < 0 || caph_enter() < 0) 66 err(1, "capsicum"); 67 68 /* This utility may NOT do getopt(3) option parsing. */ 69 if (*++argv && !strcmp(*argv, "-n")) { 70 ++argv; 71 --argc; 72 nflag = 1; 73 } else 74 nflag = 0; 75 76 veclen = (argc >= 2) ? (argc - 2) * 2 + 1 : 0; 77 78 if ((vp = iov = malloc((veclen + 1) * sizeof(struct iovec))) == NULL) 79 err(1, "malloc"); 80 81 while (argv[0] != NULL) { 82 size_t len; 83 84 len = strlen(argv[0]); 85 86 /* 87 * If the next argument is NULL then this is the last argument, 88 * therefore we need to check for a trailing \c. 89 */ 90 if (argv[1] == NULL) { 91 /* is there room for a '\c' and is there one? */ 92 if (len >= 2 && 93 argv[0][len - 2] == '\\' && 94 argv[0][len - 1] == 'c') { 95 /* chop it and set the no-newline flag. */ 96 len -= 2; 97 nflag = 1; 98 } 99 } 100 vp->iov_base = *argv; 101 vp++->iov_len = len; 102 if (*++argv) { 103 vp->iov_base = space; 104 vp++->iov_len = 1; 105 } 106 } 107 if (!nflag) { 108 veclen++; 109 vp->iov_base = newline; 110 vp++->iov_len = 1; 111 } 112 /* assert(veclen == (vp - iov)); */ 113 while (veclen) { 114 int nwrite; 115 116 nwrite = (veclen > IOV_MAX) ? IOV_MAX : veclen; 117 if (writev(STDOUT_FILENO, iov, nwrite) == -1) 118 err(1, "write"); 119 iov += nwrite; 120 veclen -= nwrite; 121 } 122 return 0; 123 } 124