Is any alias equivalent to a function, in the sense that each appearance of the alias can be replaced with the function's name, and the function name in each call to the function can be replaced with the alias?
If I am correct, an arbitrary alias is defined in the following form:
alias myalias=blahblah Is the alias defined in the above form always equivalent to a function defined as
myfun () { blahblah $@ } ?
If not, what function is the alias equivalent to?
Thanks.
As the fine manual tells us, aliases are almost completely superceded by functions. Functions can do pretty much anything an alias can do, and are capable of doing a lot more as they take arguments which can be used in arbitrary order.
The thing that functions can't do is prevent the expansion of their arguments. This means that the only reason for using an alias is to set up a function call without expansion.
alias funny='set -f; _funny' _funny(){ set +f ; do_something_with_unexpanded_args ;} and now you can run funny * and see the * rather than a list of the files in the current directory.
NO function is always equivalent to a given alias, since::
$ alias foo=bar + alias foo=bar $ myfun () { bar "$@"; } Now, let us use foo and myfun to define a function:
$ foo () { blah "$@"; } $ myfun () { blah "$@"; } What happens to foo and myfun?
$ type -a foo bar myfun + type -a foo bar myfun foo is aliased to `bar' bar is a function bar () { blah "$@" } myfun is a function myfun () { blah "$@" } Clearly, the function that was a supposed equivalent of the alias got redefined, but the alias was unaffected.
For most other cases, myfun would have been an equivalent to foo.
alias test1="echo Hello"test2(){ echo Hello ; }