at-file.texi

理解和实践操作系统的一本好书

@c This file is designed to be included in manuals that use 
@c expandargv.

@item @@@var{file}
Read command-line options from @var{file}.  The options read are
inserted in place of the original @@@var{file} option.  If @var{file}
does not exist, or cannot be read, then the option will be treated
literally, and not removed.  

Options in @var{file} are separated by whitespace.  A whitespace
character may be included in an option by surrounding the entire
option in either single or double quotes.  Any character (including a
backslash) may be included by prefixing the character to be included
with a backslash.  The @var{file} may itself contain additional
@@@var{file} options; any such options will be processed recursively.