Bash: Syntax questions about this script's errors

[null_reflections]

read greeting

case "$greeting" in
    "fu*k you" ) echo "fu*k you too!"
    ;;
    [Nn][Yy] ) echo "I think you meant to type yes or no..."
    ;;
    "Hello?" ) echo "Hello there, aren't you sexy!"
    ;;
    "i hate you" | "die, please" | "nerd" | "fu*k off" )
    echo "wow! soooo polite!"
    ;;
    * ) echo "try again!"
    continue
    ;;
esac

So above we have a functioning (yet very rude) case/switch script, where a user inputs any one of those responses on the left before the ")", and the shell answers with what matches after "echo". It took me over 20 minutes to make this because of a couple of different things:

[Nn] [Yy]

Why does bash give an error if there is white space between them?

 "i hate you" || "die, please" || "nerd" || "fu*k off"

Why do these need a pipe instead of an or symbol?

Again, this is just an exercise, i try to make them funny sometimes since no one else would care/understand anyway ;-)

 

[Antero360]

read greeting

case "$greeting" in
    "fu*k you" ) echo "fu*k you too!"
    ;;
    [Nn][Yy] ) echo "I think you meant to type yes or no..."
    ;;
    "Hello?" ) echo "Hello there, aren't you sexy!"
    ;;
    "i hate you" | "die, please" | "nerd" | "fu*k off" )
    echo "wow! soooo polite!"
    ;;
    * ) echo "try again!"
    continue
    ;;
esac

So above we have a functioning (yet very rude) case/switch script, where a user inputs any one of those responses on the left before the ")", and the shell answers with what matches after "echo". It took me over 20 minutes to make this because of a couple of different things:

[Nn] [Yy]

Why does bash give an error if there is white space between them?

 "i hate you" || "die, please" || "nerd" || "fu*k off"

Why do these need a pipe instead of an or symbol?

Again, this is just an exercise, i try to make them funny sometimes since no one else would care/understand anyway ;-)

Might want to look up the OR operator for bash HINT HINT WINK WINK
single pipe means you are passing the result of the current command to the next command
double pipe means OR

 

[Deleted member 2829]

To address the first question:

Why does bash give an error if there is white space between them?

I'm not a big bash expert but I think it's because [Nn] [Yy] is a string and should therefore be surrounded by quotes just like the other strings in the case. If [Nn][Yy] works, it would seem that bash only requires the quotes when the string contains whitespace. Personally I would use the quotes anyway (unless that breaks it of course).

 

[null_reflections]

Might want to look up the OR operator for bash HINT HINT WINK WINK
single pipe means you are passing the result of the current command to the next command
double pipe means OR

So I guess OR only takes two operands? I'm wondering if you could use it like if/else/elif

 

[Antero360]

So I guess OR only takes two operands? I'm wondering if you could use it like if/else/elif

not sure what you mean there bud

 

[null_reflections]

not sure what you mean there bud

Online it says 2 operands, I'm wondering if you could do something like...x OR y OR z, I would be more descriptive but I'm away on my phone

 

[Antero360]

Online it says 2 operands, I'm wondering if you could do something like...x OR y OR z, I would be more descriptive but I'm away on my phone

here's a little something for ya

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