Shell Programming and Scripting

Hi,

I have a task of "encrypting" a file by replacing the numbers with another set of numbers. Sort of swapping the values, say:

1 = 5
2 = 8
3 = 7
4 = 1
5 = 9 and so on..

so if i have 12345, my output should be 58719.

problem is i get 98719 since after swapping 1 to 5, my sed command has yet to pass the 5 to 9 swap, so the 5 that was swapped from 1 is being swapped a second time to 9.

my test code is:

Code:

echo 12345 | sed -e 's/1/5/g;s/2/8/g;s/3/7/g;s/4/1/g;s/5/9/g;'

Is there a better solution for this?

Thanks.

Is this homework?

You can use the sed's transform feature for this...

Code:

echo 12345 | sed 'y/12345/58719/'

--ahamed

hi zaxxon,

Nope. Just a task at work i'm having a hard time coding. Been trying with a few algorithms for the past hour or so. Just thought there might be help from others while I'm figuring it out.

Thanks.

See ahamed's post above. I hope this is not being used for encrypting Having several tries you will easily guess which number translates to which so this does not really look suited for a professional environment; no offense.

Telling sed that the second number 5 is at the end of the string works:

Code:

echo 12345 | sed -e 's/1/5/g;s/2/8/g;s/3/7/g;s/4/1/g;s/5$/9/g;'

58719

Hope this helps.

tr is much, much, much better suited for this than sed. No tricks are required to prevent repeat substitution and you feed it the sets directly.

Code:

$ echo 123456789 | tr '[12345]' '[58719]'
587196789

$