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 __FBSDID("$FreeBSD$"); 45 46 #include <sys/types.h> 47 #include <sys/uio.h> 48 49 #include <assert.h> 50 #include <capsicum_helpers.h> 51 #include <err.h> 52 #include <errno.h> 53 #include <limits.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <unistd.h> 57 58 /* 59 * Report an error and exit. 60 * Use it instead of err(3) to avoid linking-in stdio. 61 */ 62 static __dead2 void 63 errexit(const char *prog, const char *reason) 64 { 65 char *errstr = strerror(errno); 66 write(STDERR_FILENO, prog, strlen(prog)); 67 write(STDERR_FILENO, ": ", 2); 68 write(STDERR_FILENO, reason, strlen(reason)); 69 write(STDERR_FILENO, ": ", 2); 70 write(STDERR_FILENO, errstr, strlen(errstr)); 71 write(STDERR_FILENO, "\n", 1); 72 exit(1); 73 } 74 75 int 76 main(int argc, char *argv[]) 77 { 78 int nflag; /* if not set, output a trailing newline. */ 79 int veclen; /* number of writev arguments. */ 80 struct iovec *iov, *vp; /* Elements to write, current element. */ 81 char space[] = " "; 82 char newline[] = "\n"; 83 char *progname = argv[0]; 84 85 if (caph_limit_stdio() < 0 || caph_enter() < 0) 86 err(1, "capsicum"); 87 88 /* This utility may NOT do getopt(3) option parsing. */ 89 if (*++argv && !strcmp(*argv, "-n")) { 90 ++argv; 91 --argc; 92 nflag = 1; 93 } else 94 nflag = 0; 95 96 veclen = (argc >= 2) ? (argc - 2) * 2 + 1 : 0; 97 98 if ((vp = iov = malloc((veclen + 1) * sizeof(struct iovec))) == NULL) 99 errexit(progname, "malloc"); 100 101 while (argv[0] != NULL) { 102 size_t len; 103 104 len = strlen(argv[0]); 105 106 /* 107 * If the next argument is NULL then this is this 108 * the last argument, therefore we need to check 109 * for a trailing \c. 110 */ 111 if (argv[1] == NULL) { 112 /* is there room for a '\c' and is there one? */ 113 if (len >= 2 && 114 argv[0][len - 2] == '\\' && 115 argv[0][len - 1] == 'c') { 116 /* chop it and set the no-newline flag. */ 117 len -= 2; 118 nflag = 1; 119 } 120 } 121 vp->iov_base = *argv; 122 vp++->iov_len = len; 123 if (*++argv) { 124 vp->iov_base = space; 125 vp++->iov_len = 1; 126 } 127 } 128 if (!nflag) { 129 veclen++; 130 vp->iov_base = newline; 131 vp++->iov_len = 1; 132 } 133 /* assert(veclen == (vp - iov)); */ 134 while (veclen) { 135 int nwrite; 136 137 nwrite = (veclen > IOV_MAX) ? IOV_MAX : veclen; 138 if (writev(STDOUT_FILENO, iov, nwrite) == -1) 139 errexit(progname, "write"); 140 iov += nwrite; 141 veclen -= nwrite; 142 } 143 return 0; 144 } 145