UNIX® Shells by Example, Third Edition

C.3. Double Quotes

1. Must be matched.

2. Protect all metacharacters from interpretation except the following:

   1. Itself.

   2. Exclamation point (csh only).

   3. $ used for variable substitution.

   4. ' ' Backquotes for command substitution.

Examples:

C Shell	Bourne Shell	Korn Shell
echo "Hello $LOGNAME\!"	echo "Hello $LOGNAME!"	print "Hello $LOGNAME!"
echo "I don't care"	echo "I don't care"	print "I don't care"
echo "The date is 'date'"	echo "The date is 'date'"	print "The date is $(date)"
echo "\\\\"	echo "\\\\"	print "\\\\"
\\\\	\	\