1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if 0 35 #ifndef lint 36 static char const copyright[] = 37 "@(#) Copyright (c) 1989, 1993\n\ 38 The Regents of the University of California. All rights reserved.\n"; 39 #endif /* not lint */ 40 41 #ifndef lint 42 static char sccsid[] = "@(#)echo.c 8.1 (Berkeley) 5/31/93"; 43 #endif /* not lint */ 44 #endif 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include <sys/types.h> 49 #include <sys/uio.h> 50 51 #include <assert.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 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 /* This utility may NOT do getopt(3) option parsing. */ 86 if (*++argv && !strcmp(*argv, "-n")) { 87 ++argv; 88 --argc; 89 nflag = 1; 90 } else 91 nflag = 0; 92 93 veclen = (argc >= 2) ? (argc - 2) * 2 + 1 : 0; 94 95 if ((vp = iov = malloc((veclen + 1) * sizeof(struct iovec))) == NULL) 96 errexit(progname, "malloc"); 97 98 while (argv[0] != NULL) { 99 size_t len; 100 101 len = strlen(argv[0]); 102 103 /* 104 * If the next argument is NULL then this is this 105 * the last argument, therefore we need to check 106 * for a trailing \c. 107 */ 108 if (argv[1] == NULL) { 109 /* is there room for a '\c' and is there one? */ 110 if (len >= 2 && 111 argv[0][len - 2] == '\\' && 112 argv[0][len - 1] == 'c') { 113 /* chop it and set the no-newline flag. */ 114 len -= 2; 115 nflag = 1; 116 } 117 } 118 vp->iov_base = *argv; 119 vp++->iov_len = len; 120 if (*++argv) { 121 vp->iov_base = space; 122 vp++->iov_len = 1; 123 } 124 } 125 if (!nflag) { 126 veclen++; 127 vp->iov_base = newline; 128 vp++->iov_len = 1; 129 } 130 /* assert(veclen == (vp - iov)); */ 131 while (veclen) { 132 int nwrite; 133 134 nwrite = (veclen > IOV_MAX) ? IOV_MAX : veclen; 135 if (writev(STDOUT_FILENO, iov, nwrite) == -1) 136 errexit(progname, "write"); 137 iov += nwrite; 138 veclen -= nwrite; 139 } 140 return 0; 141 } 142