使用Windows批处理脚本计时进程

Question

Hi and thanks in advance,

I am newbie at developing batch files but I am trying to write a bat file right now that will create and write to a ldif file. I am starting off with something simple 1st. I also need to time the process as it may get more complicated and I may need to do software comparisons later (such as bat vs. java later).

Right now I only got this:

@ echo "LDIF Generator"
@ echo off
:: *** Enter the file here "within the double quotes"
set fileName="test.ldif"
:: *** If file exists, then erase all previous content
::if exist %fileName% ECHO Erase the file >%fileName%

echo Hello>%fileName%
echo Created LDIF File %fileName%


set /a sum = 0
for /L %%A in (1,1,5) do (
    echo %%A>>%fileName%  set a/ sum =  "%sum% + %%A"
)
echo sum is %sum%
pause

I am currently trying to figure out how to add up some numbers and time the process.

It gives me this output so far:

Hello
1  set a/ sum =  0 + 1
2  set a/ sum =  0 + 2
3  set a/ sum =  0 + 3
4  set a/ sum =  0 + 4
5  set a/ sum =  0 + 5

And on cmd sum is "0"

I am trying to it to show the current iterate sum and echo back the finally sum at the end and the time it takes to do that.

Answer 1

@ECHO OFF &SETLOCAL
set /a sum = 0
for /L %%A in (1,1,5) do (
    set /a sum+=%%A
)
echo sum is %sum%

sum is 15

Answer 2

Time calculations in batch are a major pain in the neck. Check the answers to this question for different methods, ranging from a batch script to external tools. Personally I'd prefer the PowerShell Measure-Command cmdlet.

Answer 3

Use Endoro's code or something like it. That is simpler. But by way of explanation... to use code like yours you need to enabledelayedexpansion and use ! instead of % within a FOR or IF construct to specify that you want to use the run-time value of the variable sum instead of the load-time value.

setlocal enabledelayedexpansion
set /a sum = 0
for /L %%A in (1,1,5) do (
    echo %%A>>%fileName%  set a/ sum =  "!sum! + %%A"
)
echo sum is %sum%
endlocal