Recursive function in bash

Question

I want to do a function that will return the factorial of a number in bash

Here\'s the current code that doesn\'t work, can anyone tell me what\'s wrong and how to c

Answer 1

#!/bin/bash

function factorial() 
{ 
   if (( $1 < 2 ))
   then
     echo 1
   else
     echo $(( $1 * $(factorial $(( $1 - 1 ))) ))
   fi
}

This will work better.

(It works up to 25, anyway, which should be enough to prove the point about recursion.)

For higher numbers, bc would be the tool to use, making the ninth line above:

echo "$1 * $(factorial $(( $1 - 1 )))" | bc

but you have to be a bit careful with bc --

$ factorial 260
38301958608361692351174979856044918752795567523090969601913008174806\
51475135399533485285838275429773913773383359294010103333339344249624\
06009974551133984962615380298039823284896547262282019684886083204957\
95233137023276627601257325925519566220247124751398891221069403193240\
41688318583612166708334763727216738353107304842707002261430265483385\
20637683911007815690066342722080690052836580858013635214371395680329\
58941156051513954932674117091883540235576934400000000000000000000000\
00000000000000000000000000000000000000000

was quite a strain on my poor system!