Compound if statements with multiple expressions in Bash

Question

I would like to recreate something like this

if ( arg1 || arg2 || arg 3) {}

And I did got so far, but I get the following error:

line 11: [.: command not found

if [ $char == $';' -o $char == $'\\' -o $char == $'\'' ]
then ...

I tried different ways, but none seemed to work. Some of the ones I tried.

Answer 1

For Bash, you can use the [[ ]] form rather than [ ], which allows && and || internally:

if [[ foo || bar || baz ]] ; then
  ...
fi

Otherwise, you can use the usual Boolean logic operators externally:

[ foo ] || [ bar ] || [ baz ]

...or use operators specific to the test command (though modern versions of the POSIX specification describe this XSI extension as deprecated -- see the APPLICATION USAGE section):

[ foo -o bar -o baz ]

...which is a differently written form of the following, which is similarly deprecated:

test foo -o bar -o baz