In list context, returns a (possibly empty) list of filename expansions on the value of EXPR such as the standard Unix shell /bin/csh would do. In scalar context, glob iterates through such filename expansions, returning undef when the list is exhausted. This is the internal function implementing the <*.c> operator, but you can use it directly. If EXPR is omitted, $_ is used. The <*.c> operator is discussed in more detail in "I/O Operators" in perlop.
Note that glob splits its arguments on whitespace and treats each segment as separate pattern. As such, glob("*.c *.h") matches all files with a .c or .h extension. The expression glob(".* *") matches all files in the current working directory.
If non-empty braces are the only wildcard characters used in the glob, no filenames are matched, but potentially many strings are returned. For example, this produces nine strings, one for each pairing of fruits and colors:
@many = glob "{apple,tomato,cherry}={green,yellow,red}";Beginning with v5.6.0, this operator is implemented using the standard File::Glob extension. See File::Glob for details, including bsd_glob which does not treat whitespace as a pattern separator.