Created
October 6, 2019 21:30
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Encode / Decode Ascii Text by shifting chars
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| #!/usr/bin/env bash | |
| function asciirotby { | |
| case $1 in | |
| "+1" | "-25") tr 'a-zA-Z' 'b-za-aB-ZA-A';; #Rotates by +1 , go to next letter (a becomes b) or rotate -25 (25 letters back) | |
| "+2" | "-24") tr 'a-zA-Z' 'c-za-bC-ZA-B';; #Rotates by +2 , go to next 2 letters (a becomes c) | |
| "+3" | "-23") tr 'a-zA-Z' 'd-za-cD-ZA-C';; #Ceasar Cipher - rotate by 3 | |
| "+4" | "-22") tr 'a-zA-Z' 'e-za-dE-ZA-D';; | |
| "+5" | "-21") tr 'a-zA-Z' 'f-za-eF-ZA-E';; | |
| "+6" | "-20") tr 'a-zA-Z' 'g-za-fG-ZA-F';; | |
| "+7" | "-19") tr 'a-zA-Z' 'h-za-gH-ZA-G';; | |
| "+8" | "-18") tr 'a-zA-Z' 'i-za-hI-ZA-H';; | |
| "+9" | "-17") tr 'a-zA-Z' 'j-za-iJ-ZA-I';; | |
| "+10" | "-16") tr 'a-zA-Z' 'k-za-jK-ZA-J';; | |
| "+11" | "-15") tr 'a-zA-Z' 'l-za-kL-ZA-K';; | |
| "+12" | "-14") tr 'a-zA-Z' 'm-za-lM-ZA-L';; | |
| "+13" | "-13") tr 'a-zA-Z' 'n-za-mN-ZA-M';; | |
| "+14" | "-12") tr 'a-zA-Z' 'o-za-nO-ZA-N';; | |
| "+15" | "-11") tr 'a-zA-Z' 'p-za-oP-ZA-O';; | |
| "+16" | "-10") tr 'a-zA-Z' 'q-za-pQ-ZA-P';; | |
| "+17" | "-9") tr 'a-zA-Z' 'r-za-qR-ZA-Q';; | |
| "+18" | "-8") tr 'a-zA-Z' 's-za-rS-ZA-R';; | |
| "+19" | "-7") tr 'a-zA-Z' 't-za-sT-ZA-S';; | |
| "+20" | "-6") tr 'a-zA-Z' 'u-za-tU-ZA-T';; | |
| "+21" | "-5") tr 'a-zA-Z' 'v-za-uV-ZA-U';; | |
| "+22" | "-4") tr 'a-zA-Z' 'w-za-vW-ZA-V';; | |
| "+23" | "-3") tr 'a-zA-Z' 'x-za-wX-ZA-W';; | |
| "+24" | "-2") tr 'a-zA-Z' 'y-za-xY-ZA-X';; | |
| "+25" | "-1") tr 'a-zA-Z' 'z-za-yZ-ZA-Y';; | |
| esac | |
| } |
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Source the script running
. ./rotatechars.shThen use the function like this:
asciirotby +3to rotate / encrypt each letter by +3 chars.Alternativelly copy the function in your script. I use to keep functions like that in
.bash_aliasessince this file is sourced by default when shell is loaded.Symbol
+means add 3 chars , symbol-subtract 3 chars.You can add or subtract any number of chars.
Example: