Shell special variables
- $1 - $9
- these variables are the positional parameters.
- $0
- the name of the command currently being executed.
- $#
- the number of positional arguments given to this invocation of the shell.
- $?
- the exit status of the last command executed is given as a decimal string. When a command completes successfully, it returns the exit status of 0 (zero), otherwise it returns a non-zero exit status.
- $$
- the process number of this shell - useful for including in filenames, to make them unique.
- $!
- the process id of the last command run in the background.
- $-
- the current options supplied to this invocation of the shell.
- $*
- a string containing all the arguments to the shell, starting at $1.
- $@@
- same as above, except when quoted.
page revision: 1, last edited: 03 Apr 2009 17:04
