xv -wait 0 *.gif *.jpgwhere perhaps no *.gif files are present (and this is not an error). However, POSIX requires that a wildcard pattern is left unchanged when it is syntactically incorrect, or the list of matching pathnames is empty. With bash one can force the classical behaviour by setting allow_null_glob_expansion=true.
rm `find . -name "*~"`new scripts require
rm -f nosuchfile `find . -name "*~"`to avoid error messages from rm called with an empty argument list.)
[:alnum:] [:alpha:] [:blank:] [:cntrl:] [:digit:] [:graph:] [:lower:] [:print:] [:punct:] [:space:] [:upper:] [:xdigit:]so that one can say `[[:lower:]]' instead of `[a-z]', and have things work in Denmark, too, where there are three letters past `z' in the alphabet. These character classes are defined by the LC_CTYPE category in the current locale.