incremental loop

[farjibaba]

Dear friends

say i have a file like

1
2
3
5
8
9
16
17
35
36
.
.
..
till 50

now I ask user to give a input between 1 to 50.
now there are two condition
First: if the number is found in file then script should display the number --------------- no problem grep woks it for me
Second: but problem is this if the number given by user; does not found in the file then script should display the very next no to the screen. like say

echo " give a number between 1 to 50 " # user gives 5 !!! then script should display $read1
# if user gives 10 then script should display the very next no to 10 is 16.............

please help me ........

thanks to you all

[jlittle]

I assume you're scripting in bash. I suggest loading the file into a bash indexed array; then you can look it up with a for loop.

Say your file is "numbers.txt", and the user has input "num":

arr=($(<numbers.txt))
for (( i=0; i < ${#arr[*]}; ++i )); do
    (( arr[i] >= num )) && break;
done
echo The first number on or after $num is ${arr[i]}

Regards, John Little

Note you'd want to handle going off the end, that would be i == ${#arr[*])