Linux and Unix Shell Programming

15.5. Backslash

The backslash stops the shell from misinterpreting the next character if it has special meaning to the shell. The following characters may have special meaning: & * = ^ $ ` " | ?.

Issuing the echo command with an * causes a listing of the whole current directory in a squashed up format, instead of echoing just the asterisk.

						$ echo * 

conf.linuxconf conf.modules cron.daily cron.hourly cron.monthly 
cron.weekly crontab csh.cshrc default dosemu.conf dosemu.users exports 
fdprm fstab gettydefs gpm-root.c 
onf group group- host.conf hosts hosts.allow hosts.deny httpd inetd 
...
					

To disable the special meaning of the asterisk, use a backslash.

						$ echo \* 
*
					

The same thing goes for the $$ command which the shell interprets as your current ...