Find and Replace (Encryption)

[Jacob]

I am in the process of making some kind of encrypter and decrypter, for this I need to find and replace letters, for instance "a" will be replaced with "$".

I have already searched around but the topics I have seen are inconclusive, thanks to anybody who offers any kind of support.

I am looking for help on how to find and replace strings in a text file.

[Prince_]

for instance "a" will be replaced with "$".

what if there is $ in the original codes?

[Jacob]

for instance "a" will be replaced with "$".

what if there is $ in the original codes?

It's a text file. It is only meant to contain text. Then if that happens I will replace "a" with "\$1" it was simply an example, to help the person who answers my question.

Besides, then "$" will be replaced with "^&".

[Prince_]

i think you may replace each other in the 26 chars.
e.g.

a->b
b->c
c->d
...
z->a

[Jacob]

You don't get it do you.
I will be replacing only text but I can encrypt that into any symbol.

Code: [Select]

a -> !!
b -> *!
c -> (!
d -> ^!
e -> :!as an example, and to decrypt:

Code: [Select]

!! -> a
*! -> b
(! -> c
^! -> d
:! -> eI would prefer it if you no longer posted if you can provide no help on my topic.

[Prince_]

srr, but what help do you need? i dun follow you...

[Dias de verano]

To replace text in a string, you can use the set command thus

set string=%string:a=b%

where a and b are strings

Code: [Select]

C:\>set string=bab

C:\>set string=%string:a=o%

C:\>echo %string%
bob

C:\>set string=%string:o=eee%

C:\>echo %string%
beeeb

C:\>set string=%string:e=^!%

C:\>echo %string%
b!!!b

[Jacob]

To replace text in a string, you can use the set command thus

set string=%string:a=b%

where a and b are strings

Code: [Select]

C:\>set string=bab

C:\>set string=%string:a=o%

C:\>echo %string%
bob

C:\>set string=%string:o=eee%

C:\>echo %string%
beeeb

C:\>set string=%string:e=^!%

C:\>echo %string%
b!!!b

Thanks you very much, problem solved.
But how would i get this to run through everything in a text file rather than just a variable.

[Dias de verano]

But how would i get this to run through everything in a text file rather than just a variable.

An interesting exercise for you, Jacob.

You can read the text file line by line into a variable using FOR, as I am sure you must know by now. Inside the loop you can do all the string replacements in the line of text, and then write it out to a new file.

[Prince_]

you dun know how to replace a char in a string? ...
then i have to tell you that there are lots of limitations when the cmd.exe dealing with the replacement.
i advise that you give up your complex idea about the encryption, juz use my method.

[Jacob]

But how would i get this to run through everything in a text file rather than just a variable.

An interesting exercise for you, Jacob.

You can read the text file line by line into a variable using FOR, as I am sure you must know by now. Inside the loop you can do all the string replacements in the line of text, and then write it out to a new file.

Sorry, I do not know how to set a line as a variable.

[Dias de verano]

you dun know how to replace a char in a string? ...
then i have to tell you that there are lots of limitations when the cmd.exe dealing with the replacement.
i advise that you give up your complex idea about the encryption, juz use my method.

What method? I don't see any method. Just an idea. Both your idea and Jacob's are equivalent. The classic simple substitution cypher.

[Dias de verano]

But how would i get this to run through everything in a text file rather than just a variable.

An interesting exercise for you, Jacob.

You can read the text file line by line into a variable using FOR, as I am sure you must know by now. Inside the loop you can do all the string replacements in the line of text, and then write it out to a new file.

Sorry, I do not know how to set a line as a variable.

You did on Oct 24th

http://www.computerhope.com/forum/index.php/topic,69075.msg451057.html#msg451057

[Jacob]

Code: [Select]

If in doubt, delims== will always grab the whole line (which is what you want.) Note I used set /a because the 2nd line of the output file
from wmic contains a TAB character after the percentage number, which I wanted to remove

So, I did, thanks, and sorry. 

[Prince_]

Sorry, I do not know how to set a line as a variable.

...

Code: [Select]

C:\>type test.txt
hello
world
C:\>for /f %a in (test.txt) do @set line=%a

C:\>echo %line%
world