in at&t assembly: Implement a cryptographic encoder$/$decoder that will input a line of text and output an

encoding of the text. The method will be similar to Caesar$$s cipher and ROT$13$system$.$ The user will

provide a verb $($encode or decode$)$and an integer key as a command line argument. This key will be

a decimal number. For each of the characters in the line of text to be encoded:

$1$

$$if it is between the space and the tilde $(),$use the formula c

$=((($c $32)+$key$)$mod $95)+32$

to compute the encoded character

$$if it is less than the space, use the character as is$.$

$$if it is after the tilde, use the character as is$.$

To decode, follow this method:

$$if it is between space and the tilde $(),$use the formula c

$=(((($c $32)$key$)$mod $95)+95)$

mod $95+32$to compute the encoded character

$$if it is less than space, use the character as is$.$

$$if it is after the tilde, use the character as is$.$

Here are some sample runs you should be able to produce.

$ echo "abcDEF" $|./$crypto encode $13$

nopQRS

$ echo "abcDEF" $|./$crypto encode $91$

$]^\_$@AB

$ echo "Hello, world!" $|./$crypto encode $3771$

$+$HOORnbZRUOGc

$ echo $$cde$|./$crypto decode $2$

abc

$ echo $$Hello$,$world$!|./$crypto encode $2173|./$crypto decode $2173$

Hello, world!

In order to access the command line arguments, remember that stdlib is calling main with this signature:

int main$($int argc, char $*$argv$[])$

To read the string, use fgets and not scanf$("\%$s$",..)$since the latter will stop at the first white

space.

Save your program as crytpo.s$.$