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It seems to me that they both store all the command-line arguments.
So is there a difference between the two?
249
There is no difference if you do not put $* or $@ in quotes. But if you put them inside quotes (which you should, as a general good practice), then $@ will pass your parameters as separate parameters, whereas $* will just pass all params as a single parameter.
"$@" Stores all the arguments that were entered on the command line, individually quoted ("$1" "$2" ...). So basically, $# is a number of arguments given when your script was executed. $* is a string containing all arguments. For example, $1 is the first argument and so on.
It's a space separated string of all arguments. For example, if $1 is "hello" and $2 is "world", then $* is "hello world".
The $@ holds list of all arguments passed to the script. The $* holds list of all arguments passed to the script.
The difference is subtle; "$*" creates one argument separated by the $IFS variable, while "$@" will expand into separate arguments. As an example, consider:
for i in "$@"; do echo "@ '$i'"; done for i in "$*"; do echo "* '$i'"; done When run with multiple arguments:
./testvar foo bar baz 'long arg' @ 'foo' @ 'bar' @ 'baz' @ 'long arg' * 'foo bar baz long arg' For more details:
http://www.gnu.org/software/bash/manual/bashref.html#Special-Parameters
$*
Expands to the positional parameters, starting from one. When the expansion occurs within double quotes, it expands to a single word with the value of each parameter separated by the first character of the IFS special variable. That is, "$*" is equivalent to "$1c$2c...", where c is the first character of the value of the IFS variable. If IFS is unset, the parameters are separated by spaces. If IFS is null, the parameters are joined without intervening separators.
$@
Expands to the positional parameters, starting from one. When the expansion occurs within double quotes, each parameter expands to a separate word. That is, "$@" is equivalent to "$1" "$2" .... If the double-quoted expansion occurs within a word, the expansion of the first parameter is joined with the beginning part of the original word, and the expansion of the last parameter is joined with the last part of the original word. When there are no positional parameters, "$@" and $@ expand to nothing (i.e., they are removed).
191
A key difference from my POV is that "$@" preserves the original number of arguments. It's the only form that does.
For example, if file my_script contains:
#!/bin/bash main() { echo 'MAIN sees ' $# ' args' } main $* main $@ main "$*" main "$@" ### end ### and I run it like this:
my_script 'a b c' d e I will get this output:
MAIN sees 5 args MAIN sees 5 args MAIN sees 1 args MAIN sees 3 args If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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