diff --git a/usr.bin/yes/yes.1 b/usr.bin/yes/yes.1 index 8ed8beab0d28..689031345dc3 100644 --- a/usr.bin/yes/yes.1 +++ b/usr.bin/yes/yes.1 @@ -1,52 +1,54 @@ .\" Copyright (c) 1980, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.Dd June 4, 2014 +.Dd March 2, 2026 .Dt YES 1 .Os .Sh NAME .Nm yes .Nd be repetitively affirmative .Sh SYNOPSIS .Nm -.Op Ar expletive +.Op Ar expletive ... .Sh DESCRIPTION The .Nm utility outputs .Ar expletive , or, by default, .Dq y , forever. +If multiple arguments are given, they are concatenated into a single +space-separated string. .Sh SEE ALSO .Xr jot 1 , .Xr seq 1 .Sh HISTORY The .Nm command appeared in .At v7 . diff --git a/usr.bin/yes/yes.c b/usr.bin/yes/yes.c index d9e896b6ea27..53224603cf95 100644 --- a/usr.bin/yes/yes.c +++ b/usr.bin/yes/yes.c @@ -1,74 +1,105 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1987, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include +/* + * Default expletive + */ +#define EXP "y\n" +#define EXPLEN strlen(EXP) + +/* + * Optimum and maximum buffer size. The optimum is just a little less + * than the default value of kern.ipc.pipe_mindirect; writing more than + * that is significantly slower, but we want to get as close as possible + * to minimize the number of system calls. The maximum is enough for a + * maximal command line plus a newline and terminating NUL. + */ +#define OPTBUF 8190 +#define MAXBUF (ARG_MAX + 2) + int main(int argc, char **argv) { - char buf[8192]; - char y[2] = { 'y', '\n' }; - char * exp = y; - size_t buflen = 0; - size_t explen = sizeof(y); - size_t more; - ssize_t ret; + static char buf[MAXBUF] = EXP; + char *end = buf + sizeof(buf), *exp, *pos = buf + EXPLEN; + size_t buflen, explen = EXPLEN; + ssize_t wlen = 0; if (caph_limit_stdio() < 0 || caph_enter() < 0) err(1, "capsicum"); - if (argc > 1) { - exp = argv[1]; - explen = strlen(exp) + 1; - exp[explen - 1] = '\n'; - } + argc -= 1; + argv += 1; - if (explen <= sizeof(buf)) { - while (buflen < sizeof(buf) - explen) { - memcpy(buf + buflen, exp, explen); - buflen += explen; + /* Assemble the expletive */ + if (argc > 0) { + /* Copy positional arguments into expletive buffer */ + for (pos = buf, end = buf + sizeof(buf); + argc > 0 && pos < end; argc--, argv++) { + /* Separate with spaces */ + if (pos > buf) + *pos++ = ' '; + exp = *argv; + while (*exp != '\0' && pos < end) + *pos++ = *exp++; } - exp = buf; - explen = buflen; + /* This should not be possible, but check anyway */ + if (pos > end - 2) + pos = end - 2; + *pos++ = '\n'; + explen = pos - buf; } - more = explen; - while ((ret = write(STDOUT_FILENO, exp + (explen - more), more)) > 0) - if ((more -= ret) == 0) - more = explen; + /* + * Double until we're past OPTBUF, then reduce buflen to exactly + * OPTBUF. It doesn't matter if that's not a multiple of explen; + * the modulo operation in the write loop will take care of that. + */ + for (buflen = explen; buflen < OPTBUF; pos += buflen, buflen += buflen) + memcpy(pos, buf, buflen); + if (explen < OPTBUF && buflen > OPTBUF) + buflen = OPTBUF; + /* Dump it to stdout */ + end = (pos = buf) + buflen; + do { + pos = buf + (pos - buf + wlen) % explen; + wlen = write(STDOUT_FILENO, pos, end - pos); + } while (wlen > 0); err(1, "stdout"); /*NOTREACHED*/ }