Computer Science - Unix - Discussion
Discussion Forum : Unix - Section 1 (Q.No. 28)
28.
Which of the following special shell variables is used to process number of the last background job?
Discussion:
2 comments Page 1 of 1.
Sruthi said:
10 years ago
I think $0 displays current shell.
Dharmajit said:
1 decade ago
$0 The filename of the current script.
$n These variables correspond to the arguments with which a script was invoked. Here n is a positive decimal number corresponding to the position of an argument (the first argument is $1, the second argument is $2, and so on).
$# The number of arguments supplied to a script.
$* All the arguments are double quoted. If a script receives two arguments, $* is equivalent to $1 $2.
$@ All the arguments are individually double quoted. If a script receives two arguments, $@ is equivalent to $1 $2.
$? The exit status of the last command executed.
$$ The process number of the current shell. For shell scripts, this is the process ID under which they are executing.
$! The process number of the last background command.
$n These variables correspond to the arguments with which a script was invoked. Here n is a positive decimal number corresponding to the position of an argument (the first argument is $1, the second argument is $2, and so on).
$# The number of arguments supplied to a script.
$* All the arguments are double quoted. If a script receives two arguments, $* is equivalent to $1 $2.
$@ All the arguments are individually double quoted. If a script receives two arguments, $@ is equivalent to $1 $2.
$? The exit status of the last command executed.
$$ The process number of the current shell. For shell scripts, this is the process ID under which they are executing.
$! The process number of the last background command.
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