What is wrong with my guessing game program?

Question

So yes I am doing this for school but I have most of the script written. I don't know what's going on with it, maybe a syntax error but it keeps messing up(or I do).

The first issue is that it keeps posting the number that you are trying to guess and it says no file or directory(I didn't think I was calling for such things). The 86 is the current random number.

./random: line 14: 86: No such file or directory

The second issue is that the program is telling me guesses are always too low(I can also get them to always be too high)

 I'm thinking of a number between 1 and 100. Your guess:6

./random: line 14: 86: No such file or directory
Sorry, your guess is too low. New guess:87

./random: line 14: 86: No such file or directory
Sorry, your guess is too low. New guess:

Here is my code:

#!/bin/bash


n1=$[($RANDOM % 100) +1]
guesses=1
echo -n "I'm thinking of a number between 1 and 100. Your guess:"

while read n2; do

if   [ $n2 = $n1 ]; then
break;  
else
echo    
if [ $n2 < $n1 ]; then 
echo -n "Sorry, your guess is too high. New guess:"
elif [ $n2 > $n1]; then
echo -n "Sorry, your guess is too low. New guess:"
fi      
fi
guesses=$((guesses+1))

done
echo
echo "Good job! It took you $guesses guesses to get the right number."

Thanks in advance.

..and you expect us to magically figure out what your code is? — Karoly Horvath, Sep 18 '13 at 22:14
I think the solution is pretty simple, whatever file or directory you are referencing is not there, or you are referencing it wrong. — Sorceri, Sep 18 '13 at 22:15
The problem is there is no such file or directory. I think the file missing is your code — But I'm Not A Wrapper Class, Sep 18 '13 at 22:16
The problem is that your telepathy is out of tune. Just like you and your program can't read a number from someone's mind, we can't read code from yours. — Geeky Guy, Sep 18 '13 at 22:16
Try using `[[` instead of `[`. Try using `-gt` instead of `>`. Try using `-lt` instead of `<`. Try using `-eq` instead of `=` — Digital Trauma, Sep 18 '13 at 22:32
Is that a bash script ? < and > are the symbols for input and output redirection in that language, if I'm not mistaken. Credits to digital trauma. — Erwin Smout, Sep 18 '13 at 22:38
@DigitalTrauma When I change the > and < it says guess too high. When I change the [ to [[ it says: I'm thinking of a number between 1 and 100. Your guess:./random: line 16: syntax error in conditional expression: unexpected token `;' ./random: line 16: syntax error near `;' ./random: line 16: `elif [[ $n2 < $n1]]; then' — troylatroy, Sep 18 '13 at 22:40
Also in the elif, you need a space between `$n1` and `]]`. I've made the edits I suggested and it seems to work correctly. — Digital Trauma, Sep 18 '13 at 22:43
@DigitalTrauma Nice catch on the space. I switched that and the < and > to -gt and -lt and it seems to work just fine. Post it as an answer and I'll mark it solved. — troylatroy, Sep 18 '13 at 22:54

Digital Trauma · Accepted Answer · 2013-09-18T23:47:40.843

Here's the answer as described in the comments above:

#!/bin/bash


n1=$[($RANDOM % 100) +1]
guesses=1
echo -n "I'm thinking of a number between 1 and 100. Your guess:"

while read n2; do

if   [[ $n2 -eq $n1 ]]; then
break;  
else
echo    
if [[ $n2 -gt $n1 ]]; then 
echo -n "Sorry, your guess is too high. New guess:"
elif [[ $n2 -lt $n1 ]]; then
echo -n "Sorry, your guess is too low. New guess:"
fi      
fi
guesses=$((guesses+1))

done
echo
echo "Good job! It took you $guesses guesses to get the right number."

In general you need to pay attention to the error messages bash is giving you:

./random: line 14: 86: No such file or directory

Line 14 is:

if [ $n2 < $n1 ]; then

and we know $n1 is 86 in this case. So this means the script is attempting to run 86 as if it were a command, hence the file not found error. Why is bash doing this? Well its probably interpreting < as a redirection instead of a greater-than operator. So there is something wrong with the if conditional syntax. Time to dig out the manuals http://www.gnu.org/software/bash/manual/bashref.html#Conditional-Constructs

The [[ still break the code but it works if you just have a single [. — troylatroy, Sep 18 '13 at 22:57
Oops, I also forgot to add the space between `$n1` and `]]` in the elif. Edited... now it works with `[[` `]]` as expected. — Digital Trauma, Sep 18 '13 at 23:03
More reading on the differences between `[` and `[[`: http://stackoverflow.com/questions/13542832/bash-if-difference-between-square-brackets-and-double-square-brackets — Digital Trauma, Sep 18 '13 at 23:07

What is wrong with my guessing game program?

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