@node Quoting @section Quoting @c Copyright (C) 2005, 2009-2012 Free Software Foundation, Inc. @c Permission is granted to copy, distribute and/or modify this document @c under the terms of the GNU Free Documentation License, Version 1.3 or @c any later version published by the Free Software Foundation; with no @c Invariant Sections, with no Front-Cover Texts, and with no Back-Cover @c Texts. A copy of the license is included in the ``GNU Free @c Documentation License'' file as part of this distribution. @cindex Quoting @findex quote @findex quotearg Gnulib provides @samp{quote} and @samp{quotearg} modules to help with quoting text, such as file names, in messages to the user. Here's an example of using @samp{quote}: @example #include ... error (0, errno, _("cannot change owner of %s"), quote (fname)); @end example This differs from @example error (0, errno, _("cannot change owner of '%s'"), fname); @end example @noindent in that @code{quote} escapes unusual characters in @code{fname}, e.g., @samp{'} and control characters like @samp{\n}. @findex quote_n However, a caveat: @code{quote} reuses the storage that it returns. Hence if you need more than one thing quoted at the same time, you need to use @code{quote_n}. @findex quotearg_alloc Also, the quote module is not suited for multithreaded applications. In that case, you have to use @code{quotearg_alloc}, defined in the @samp{quotearg} module, which is decidedly less convenient.