echo.c revision 256281
1143206Sdas/*- 2143206Sdas * Copyright (c) 1989, 1993 3143206Sdas * The Regents of the University of California. All rights reserved. 4143206Sdas * 5143206Sdas * Redistribution and use in source and binary forms, with or without 6143206Sdas * modification, are permitted provided that the following conditions 7143206Sdas * are met: 8143206Sdas * 1. Redistributions of source code must retain the above copyright 9143206Sdas * notice, this list of conditions and the following disclaimer. 10143206Sdas * 2. Redistributions in binary form must reproduce the above copyright 11143206Sdas * notice, this list of conditions and the following disclaimer in the 12143206Sdas * documentation and/or other materials provided with the distribution. 13143206Sdas * 4. Neither the name of the University nor the names of its contributors 14143206Sdas * may be used to endorse or promote products derived from this software 15143206Sdas * without specific prior written permission. 16143206Sdas * 17143206Sdas * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18143206Sdas * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19143206Sdas * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20143206Sdas * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21143206Sdas * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22143206Sdas * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23143206Sdas * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24143206Sdas * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25143206Sdas * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26143206Sdas * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27143206Sdas * SUCH DAMAGE. 28143206Sdas */ 29143206Sdas 30143206Sdas#if 0 31143206Sdas#ifndef lint 32143206Sdasstatic char const copyright[] = 33143206Sdas"@(#) Copyright (c) 1989, 1993\n\ 34143206Sdas The Regents of the University of California. All rights reserved.\n"; 35143206Sdas#endif /* not lint */ 36143206Sdas 37143206Sdas#ifndef lint 38143206Sdasstatic char sccsid[] = "@(#)echo.c 8.1 (Berkeley) 5/31/93"; 39143206Sdas#endif /* not lint */ 40143206Sdas#endif 41143206Sdas#include <sys/cdefs.h> 42143206Sdas__FBSDID("$FreeBSD: stable/10/bin/echo/echo.c 181269 2008-08-04 01:25:48Z cperciva $"); 43143206Sdas 44143206Sdas#include <sys/types.h> 45143206Sdas#include <sys/uio.h> 46143206Sdas 47143206Sdas#include <assert.h> 48143206Sdas#include <errno.h> 49143206Sdas#include <limits.h> 50143206Sdas#include <stdlib.h> 51143206Sdas#include <string.h> 52143206Sdas#include <unistd.h> 53143206Sdas 54143206Sdas/* 55143206Sdas * Report an error and exit. 56143206Sdas * Use it instead of err(3) to avoid linking-in stdio. 57143206Sdas */ 58143206Sdasstatic __dead2 void 59143206Sdaserrexit(const char *prog, const char *reason) 60143206Sdas{ 61143206Sdas char *errstr = strerror(errno); 62143206Sdas write(STDERR_FILENO, prog, strlen(prog)); 63143206Sdas write(STDERR_FILENO, ": ", 2); 64143206Sdas write(STDERR_FILENO, reason, strlen(reason)); 65143206Sdas write(STDERR_FILENO, ": ", 2); 66143206Sdas write(STDERR_FILENO, errstr, strlen(errstr)); 67143206Sdas write(STDERR_FILENO, "\n", 1); 68143206Sdas exit(1); 69143206Sdas} 70143206Sdas 71143206Sdasint 72main(int argc, char *argv[]) 73{ 74 int nflag; /* if not set, output a trailing newline. */ 75 int veclen; /* number of writev arguments. */ 76 struct iovec *iov, *vp; /* Elements to write, current element. */ 77 char space[] = " "; 78 char newline[] = "\n"; 79 char *progname = argv[0]; 80 81 /* This utility may NOT do getopt(3) option parsing. */ 82 if (*++argv && !strcmp(*argv, "-n")) { 83 ++argv; 84 --argc; 85 nflag = 1; 86 } else 87 nflag = 0; 88 89 veclen = (argc >= 2) ? (argc - 2) * 2 + 1 : 0; 90 91 if ((vp = iov = malloc((veclen + 1) * sizeof(struct iovec))) == NULL) 92 errexit(progname, "malloc"); 93 94 while (argv[0] != NULL) { 95 size_t len; 96 97 len = strlen(argv[0]); 98 99 /* 100 * If the next argument is NULL then this is this 101 * the last argument, therefore we need to check 102 * for a trailing \c. 103 */ 104 if (argv[1] == NULL) { 105 /* is there room for a '\c' and is there one? */ 106 if (len >= 2 && 107 argv[0][len - 2] == '\\' && 108 argv[0][len - 1] == 'c') { 109 /* chop it and set the no-newline flag. */ 110 len -= 2; 111 nflag = 1; 112 } 113 } 114 vp->iov_base = *argv; 115 vp++->iov_len = len; 116 if (*++argv) { 117 vp->iov_base = space; 118 vp++->iov_len = 1; 119 } 120 } 121 if (!nflag) { 122 veclen++; 123 vp->iov_base = newline; 124 vp++->iov_len = 1; 125 } 126 /* assert(veclen == (vp - iov)); */ 127 while (veclen) { 128 int nwrite; 129 130 nwrite = (veclen > IOV_MAX) ? IOV_MAX : veclen; 131 if (writev(STDOUT_FILENO, iov, nwrite) == -1) 132 errexit(progname, "write"); 133 iov += nwrite; 134 veclen -= nwrite; 135 } 136 return 0; 137} 138