China DOS Union

-- Unite DOS · Advance DOS · Grow DOS --
Union site: www.cn-dos.net　Forum site: www.cn-dos.net/forum

中国DOS联盟论坛
The time now is 2026-08-15 23:59

47,813 topics / 349,903 posts / today 1 new / 48,258 members

DOS疑难解答 & 问题讨论（解答室） » How can I use a return value from one parameter to verify whether my network is connected?

Floor1　萍客	Posted 2003-07-02 00:00
初级用户　Posts 19　Credits 205
In a batch file I need to check whether my machine is connected to the Internet. What I'm using is to ping a website, save the result as text, then search it for a specified string. I don't know how to use errorlevel?

Floor2　Lydong	Posted 2003-07-02 00:00
元老会员　Posts 407　Credits 1,468　From 广州
Just use PING. If the PING succeeds, errorlevel is 0; if it fails, then it is 1. Written as a batch file: @echo off echo Please wait . . . ping www.163.com >nul if errorlevel 0 echo yes if errorlevel 1 echo no

Floor3　萍客	Posted 2003-07-02 00:00
初级用户　Posts 19　Credits 205
So that's how it is, many thanks. I only knew the textbook said every command returns an erroelevel value, but I just didn't understand what it meant. In the future, if I have questions about batch files, I hope the moderator won't hesitate to give guidance.

Floor5　Wengier	Posted 2003-07-03 00:00
系统支持　Posts 10,521　Credits 27,736
if errorlevel 0 echo yes if errorlevel 1 echo no It should be changed to this, right: if not errorlevel 1 echo yes if errorlevel 1 echo no

Floor6　hunome	Posted 2003-07-03 00:00
银牌会员　Posts 721　Credits 2,265
What exactly is the difference? if not errorlevel 0 echo no if errorlevel 0 echo yes Would that work?

Floor7　萍客	Posted 2003-07-03 00:00
初级用户　Posts 19　Credits 205
Yes, after handling it that way, it seems in both cases it’s true. Can eq be used? Also, what does the >nul after ping mean? Is it assigning to a value or creating a file? Let me ask a few more questions at the same time, please help me sort them out: 1。How can I make a loop based on time, for example running once every minute? Can I jump out of the loop like break? 2。Can batch files recurse? 3。When do I need to use an escape character? Which symbol is it?

Floor8　Lydong	Posted 2003-07-11 00:00
元老会员　Posts 407　Credits 1,468　From 广州
The >nul after ping makes the text prompts produced after executing ping not display on the screen; wanting to make a time-based loop may be a bit more complicated, but you can try CountDown, a tool used to run a program within a specified period of time (mainly used in batch files). Could you explain the second and third questions a bit more clearly?

Floor10　萍客	Posted 2003-07-11 00:00
初级用户　Posts 19　Credits 205
Isn't >nul something that's in the shell under linux? It works here too, huh As for the second question, I mean whether a.bat can contain a call a.bat statement? The third question is, if I want to use quotation marks inside quotation marks, or if I want to cancel the effect of a wildcard, how can I do it? For example "he said: "..." " and wanting to find files ending with * .

Floor12　萍客	Posted 2003-07-14 00:00
初级用户　Posts 19　Credits 205
Got it. By the way, one off-topic question: are you an alumnus of Zhengzhou University? I originally came to this site from a recommendation in Computer News, and when I found that it was actually on a Zhengzhou University server, I was really quite pleased.