Test for both: boolean and string?

Question

I'd like to cheick that the one of two options are set: either the bin to true, or str is provided:

bin=false; str=; if $bin -o [ -n "$str" ]; then echo yes; fi

doesn't echoes anything, as it should be, but:

bin=false; str='str'; if $bin -o [ -n "$str" ]; then echo yes; fi

doesn't echo either - while it should. What do I do wrong?

choroba · Accepted Answer · 2012-08-03 08:53:37Z

1

Your -o option is getting passed to false. You need ||:

bin=false; str=; if $bin || [ -n "$str" ]; then echo yes; fi
bin=false; str='str'; if $bin || [ -n "$str" ]; then echo yes; fi

answered Aug 3, 2012 at 8:53

choroba

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3 Comments

Dennis Williamson Over a year ago

@Adobe: The reason that -o isn't working is that it's not part of if syntax (it's not getting passed to false, but with false to if), but it's part of the syntax of test (aka [).

choroba Over a year ago

@DennisWilliamson: Set $bin to echo. You will see that -o is getting passed to $bin, whose result goes to if.

Dennis Williamson Over a year ago

Thanks for pointing that out. I overlooked the fact that if executes its argument. However, the part I said about test is correct.

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