I need to get my wifi scanning while I run Wireshark in Ubuntu. I tried some of the scripts that I found on the internet, but they did not run correctly. So, I decided to write my own very simple script. I know there are more elegant ways to do this, but I decided to keep things as simple as possible, after verifying that if I enter, for example, sudo iwconfig wlan0 channel 1 that the wifi modem tunes to channel 1. So, what I want to do is to continuously scan through the a and b channels while running Wireshark. I want it to dwell on each channel for 0.1 seconds. But, every time I try to run this shell script, I get an "unexpected end of file" error. What is wrong? I suspect it is something simple and stupid, but I can't spot it.
#!/bin/bash
while true
do
iwconfig mon0 channel 1
sleep .1
iwconfig mon0 channel 2
sleep .1
iwconfig mon0 channel 3
sleep .1
iwconfig mon0 channel 4
sleep .1
iwconfig mon0 channel 5
sleep .1
iwconfig mon0 channel 6
sleep .1
iwconfig mon0 channel 7
sleep .1
iwconfig mon0 channel 8
sleep .1
iwconfig mon0 channel 9
sleep .1
iwconfig mon0 channel 10
sleep .1
iwconfig mon0 channel 11
sleep .1
iwconfig mon0 channel 36
sleep .1
iwconfig mon0 channel 40
sleep .1
iwconfig mon0 channel 44
sleep .1
iwconfig mon0 channel 48
sleep .1
iwconfig mon0 channel 52
sleep .1
iwconfig mon0 channel 56
sleep .1
iwconfig mon0 channel 60
sleep .1
iwconfig mon0 channel 64
sleep .1
iwconfig mon0 channel 149
sleep .1
iwconfig mon0 channel 153
sleep .1
iwconfig mon0 channel 157
sleep .1
iwconfig mon0 channel 161
sleep .1
done

Nothing wrong with the bash syntax, maybe you have odd hidden characters? did you use a windows text editor to make the script if so you will have windows style line endings which would produce that or a similar error

I did use the windows text editor to create the script, although I did some modifications in Gedit. How do I find and eliminate the extra characters? As I said, latest version edited and saved with Gedit.

usually that means \r\n at the end of line which may cause such kind of errors.
use od -xv filename for example to check it

Thanks. That was the problem. I ran dos2unix on the file and it works now.

> I tried some of the scripts that I found on the internet, but they did not run correctly.

why not? i'm sure the authors hoped what they spent time writing and releasing could be used by others.

so you tried several and they were damaged? very bad. please say what you think the cause of damage is!