Looping for every character in variable string BATCH

问题

I'm trying to loop through every character in a string . I only however know how to loop for every word in a string ussing the following:

(set /P MYTEXT=)<C:\MYTEXTFILE.txt

set MYEXAMPLE=%MYTEXT%
for %%x in (%MYEXAMPLE%) do (
ECHO DO SOMTHING
)

How can I configure it to work per character rather then per word?

回答1:

AFAIK, FOR cannot do a character-wise iteration - A possible workaround is to build a loop like this:

@ECHO OFF
:: string terminator: chose something that won't show up in the input file
SET strterm=___ENDOFSTRING___
:: read first line of input file
SET /P mytext=<C:\MYTEXTFILE.txt
:: add string terminator to input
SET tmp=%mytext%%strterm%
:loop
:: get first character from input
SET char=%tmp:~0,1%
:: remove first character from input
SET tmp=%tmp:~1%
:: do something with %char%, e.g. simply print it out
ECHO char: %char%
:: repeat until only the string terminator is left
IF NOT "%tmp%" == "%strterm%" GOTO loop

Note: The question title states that you want to loop over "every character in variable string", which suggests the input file only contains a single line, because the command (set /P MYTEXT=)<C:\MYTEXTFILE.txt will only read the first line of C:\MYTEXTFILE.txt. If you want to loop over all lines in a file instead, the solution is a bit more complicated and I suggest you open another question for that.

回答2:

This is a simple and direct way to loop through every character in a string:

@echo off
setlocal ENABLEDELAYEDEXPANSION

set /P mytext= < MYTEXTFILE.txt
echo Line is '%mytext%'

set pos=0
:NextChar
    echo Char %pos% is '!mytext:~%pos%,1!'
    set /a pos=pos+1
    if "!mytext:~%pos%,1!" NEQ "" goto NextChar

回答3:

The splitStr subroutine below:

will print out every character in the string one by one
can be safely called regardless of the state of delayed expansion
has no superslow goto loop
handles CR and LF
sets the errorLevel to the number of characters in the string

@echo off & setLocal enableExtensions disableDelayedExpansion
(call;) %= sets errorLevel to 0 =%

set "testStr=uncopyrightable"
call :splitStr testStr
if errorLevel 1 (
    >&2 echo(string is %errorLevel% char(s^) in length
) else (
    >&2 echo(empty string
    goto die
) %= if =%
goto end

:die
(call) %= sets errorLevel to 1 =%
:end
endLocal & goto :EOF

:splitStr string=
:: outputs string one character per line
setLocal disableDelayedExpansion
set "var=%1"

set "chrCount=0" & if defined var for /f "delims=" %%A in ('
    cmd /v:on /q /c for /l %%I in (0 1 8190^) do ^
    if "!%var%:~%%I,1!" neq "" (^
    echo(:^!%var%:~%%I^,1^!^) else exit 0
') do (
    set /a chrCount+=1
    echo%%A
) %= for /f =%

endLocal & exit /b %chrCount%

来源：https://stackoverflow.com/questions/15004825/looping-for-every-character-in-variable-string-batch

标签

loops

batch-file

character