<!-- Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009, 2013 The President and Fellows of Harvard College. 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 UNIVERSITY 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 UNIVERSITY 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. --> <html> <head> <title>warn</title> <body bgcolor=#ffffff> <h2 align=center>warn</h2> <h4 align=center>OS/161 Reference Manual</h4> <h3>Name</h3> <p> warn, warnx, vwarn, vwarnx - print warning messages </p> <h3>Library</h3> <p> Standard C Library (libc, -lc) </p> <h3>Synopsis</h3> <p> <tt>#include <err.h></tt><br> <br> <tt>void</tt><br> <tt>warn(const char *</tt><em>format</em><tt>, ...);</tt><br> <br> <tt>void</tt><br> <tt>warnx(const char *</tt><em>format</em><tt>, ...);</tt><br> <br> <tt>void</tt><br> <tt>vwarn(const char *</tt><em>format</em><tt>, va_list);</tt><br> <br> <tt>void</tt><br> <tt>vwarnx(const char *</tt><em>format</em><tt>, va_list);</tt><br> </p> <h3>Description</h3> <p> The <tt>warn</tt>, <tt>warnx</tt>, <tt>vwarn</tt>, and <tt>vwarnx</tt> functions print warning messages to the standard error stream. </p> <p> <tt>warnx</tt> prints the name of the program, a colon, the text generated by passing <em>format</em> and subsequent args through <A HREF=printf.html>printf</A>, and a newline. </p> <p> <tt>warn</tt> prints the same thing, except that a colon and the error string for the current error (obtained by calling <A HREF=strerror.html>strerror</A> on <A HREF=../syscall/errno.html>errno</A>) are printed prior to the newline. </p> <p> <tt>vwarnx</tt> and <tt>vwarn</tt> are the same as <tt>warnx</tt> and <tt>warn</tt> respectively, except that the additional arguments for printf are taken to have been already packaged up in a <tt>va_list</tt> by use of the <A HREF=stdarg.html>stdarg</A> facility. </p> <h3>See Also</h3> <p> <A HREF=err.html>err</A> </p> </body> </html>