How to reverse a string on Linux and Windows
Via shell script on Linux
sh-3.2# vi reverse.sh
#### Start Script #####
#!/bin/bash
input_string=”$1″
reverse_string=””
input_string_length=${#input_string}
for (( i=$input_string_length-1; i>=0; i– ))
do
reverse_string=”$reverse_string${input_string:$i:1}”
done
echo “$reverse_string”
##### End Script #####
Let’s run it:
sh-3.2# chmod 775 reverse.sh
sh-3.2# ./reverse.sh Etienne
enneitE
Via powershell script on Windows
#Let’s use the script reverse.ps1 below.
######
$string=”Etienne”
$string_array=$string -split “”
[array]::Reverse($string_array)
$string_array -join ”
#####Output#####
PS C:\Users\etienne_noumen\Documents\Etienne\Scripting> .\reverse.ps1
E t i e n n e
enneitE
Via powershell script on Windows in one line
([regex]::Matches($String,’.’,’RightToLeft’) | ForEach {$_.value}) -join ”
Via batch script on Windows
::Note: ReverseStr also calls StrLen
::and string length is not greater than 80 chars
:: but can be changed.
@echo off
SetLocal EnableDelayedExpansion
cls
set Str=Etienne
call :StrLen %Str%
echo Length=%Len%
call :ReverseStr %Str%
echo String=%Str%
echo Reverse Str=%Reverse%
exit /b
::—————-
:: Calc Var Length
::—————-
:: %*=Str to Check
:: Returns %Len%
:: —————
:StrLen %*
set Data=%*
for /L %%a in (0,1,80) do (
set Char=!Data:~%%a,1!
if not “!Char!”==”” (
set /a Len=%%a+1
) else (exit /b)
)
exit /b
::—————
:: Reverse String
::—————
:: %* Str to Reverse
:: Returns %Reverse%
::——————
:ReverseStr %*
set Data=%*
call :StrLen %Data%
for /L %%a in (!Len!,-1,0) do (
set Char=!Data:~%%a,1!
set Reverse=!Reverse!!Char!
)
exit /b
Via perl script on Windows or Linux
Via python script on Windows or Linux
def reverse_string(a_string)
return a_string[::-1]
reverse_string(“etienne”) returns “enneite”
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