Simple bash script sometimes fails
1
I have a bash script that disables a USB port if there is no internet connection and after five seconds enables it again. But SOMETIMES it fails, the script disables the port but is not enabled again. Note that I only have a one USB port. This is my script:
#!/bin/bash
while true
do
sleep 10
if ping -c 2 google.com >> /dev/null 2>&1;then
echo $(date +"%r") >> /root/log.txt
echo "Conectado a SopelaBari" >> /root/log.txt
else
echo $(date +"%r") >> /root/log.txt
echo "Sin conexion" >> /root/log.txt
echo '2-1' |tee /sys/bus/usb/drivers/usb/unbind
sleep 5
echo '2-1' |tee /sys/bus/usb/drivers/usb/bind
sleep 5
fi
sleep 30
done
I am running Ubuntu 14.04.05 and the script is run as root with crontab.
bash shell-script usb
edited 39 mins ago
Rui F Ribeiro
41.5k1483140
asked Feb 11 '18 at 16:31
AndermutuAndermutu
85
|
show 4 more comments
1
I have a bash script that disables a USB port if there is no internet connection and after five seconds enables it again. But SOMETIMES it fails, the script disables the port but is not enabled again. Note that I only have a one USB port. This is my script:
#!/bin/bash
while true
do
sleep 10
if ping -c 2 google.com >> /dev/null 2>&1;then
echo $(date +"%r") >> /root/log.txt
echo "Conectado a SopelaBari" >> /root/log.txt
else
echo $(date +"%r") >> /root/log.txt
echo "Sin conexion" >> /root/log.txt
echo '2-1' |tee /sys/bus/usb/drivers/usb/unbind
sleep 5
echo '2-1' |tee /sys/bus/usb/drivers/usb/bind
sleep 5
fi
sleep 30
done
I am running Ubuntu 14.04.05 and the script is run as root with crontab.
bash shell-script usb
edited 39 mins ago
Rui F Ribeiro
41.5k1483140
asked Feb 11 '18 at 16:31
AndermutuAndermutu
85
I don't see anything obviously wrong with your script. Try adding2> /tmp/script.logfileto the end of your crontab line and see if any error output is generated when it doesn't work. You could also try increasing thesleep 510 or 20 or so, to be sure it isn't a problem with how long it takes for the port to be disabled/enabled.
– terdon♦
Feb 11 '18 at 16:38
@terdon, thanks for your answer. Do I have to create 2> /tmp/script.logfile directory or is automatically created? I don't think time is a problem, normally it takes less than 1 sec to enable/disable the port.
– Andermutu
Feb 11 '18 at 16:42
The/tmpdirectory is created by default, just add2> /tmp/script.logfileand that will create a file calledscript.logfilein/tmp. And yes, I agree that it should take less than a second but since you say it usually works, but sometimes does not, then we're looking for something strange. So maybe it sometimes takes longer.
– terdon♦
Feb 11 '18 at 16:47
Thanks @terdon. I added the script.logfile and increased the time. I will need some time to reproduce the error. I will tell you something as soon as I can.
– Andermutu
Feb 11 '18 at 16:53
1
Great! When you have more details, please edit your question and add them there (don't write "edit" or anything, just write your question as if you had included this information from the beginning). That way, the next person to read your question will have all the information.
– terdon♦
Feb 11 '18 at 17:20
|
show 4 more comments
1
1
1
1
I have a bash script that disables a USB port if there is no internet connection and after five seconds enables it again. But SOMETIMES it fails, the script disables the port but is not enabled again. Note that I only have a one USB port. This is my script:
#!/bin/bash
while true
do
sleep 10
if ping -c 2 google.com >> /dev/null 2>&1;then
echo $(date +"%r") >> /root/log.txt
echo "Conectado a SopelaBari" >> /root/log.txt
else
echo $(date +"%r") >> /root/log.txt
echo "Sin conexion" >> /root/log.txt
echo '2-1' |tee /sys/bus/usb/drivers/usb/unbind
sleep 5
echo '2-1' |tee /sys/bus/usb/drivers/usb/bind
sleep 5
fi
sleep 30
done
I am running Ubuntu 14.04.05 and the script is run as root with crontab.
bash shell-script usb
edited 39 mins ago
Rui F Ribeiro
41.5k1483140
asked Feb 11 '18 at 16:31
AndermutuAndermutu
85
I have a bash script that disables a USB port if there is no internet connection and after five seconds enables it again. But SOMETIMES it fails, the script disables the port but is not enabled again. Note that I only have a one USB port. This is my script:
#!/bin/bash
while true
do
sleep 10
if ping -c 2 google.com >> /dev/null 2>&1;then
echo $(date +"%r") >> /root/log.txt
echo "Conectado a SopelaBari" >> /root/log.txt
else
echo $(date +"%r") >> /root/log.txt
echo "Sin conexion" >> /root/log.txt
echo '2-1' |tee /sys/bus/usb/drivers/usb/unbind
sleep 5
echo '2-1' |tee /sys/bus/usb/drivers/usb/bind
sleep 5
fi
sleep 30
done
I am running Ubuntu 14.04.05 and the script is run as root with crontab.
bash shell-script usb
bash shell-script usb
edited 39 mins ago
Rui F Ribeiro
41.5k1483140
asked Feb 11 '18 at 16:31
AndermutuAndermutu
85
edited 39 mins ago
Rui F Ribeiro
41.5k1483140
asked Feb 11 '18 at 16:31
AndermutuAndermutu
85
edited 39 mins ago
Rui F Ribeiro
41.5k1483140
edited 39 mins ago
Rui F Ribeiro
41.5k1483140
edited 39 mins ago
Rui F Ribeiro
41.5k1483140
41.5k1483140
asked Feb 11 '18 at 16:31
AndermutuAndermutu
85
asked Feb 11 '18 at 16:31
AndermutuAndermutu
85
asked Feb 11 '18 at 16:31
AndermutuAndermutu
85
85
I don't see anything obviously wrong with your script. Try adding2> /tmp/script.logfileto the end of your crontab line and see if any error output is generated when it doesn't work. You could also try increasing thesleep 510 or 20 or so, to be sure it isn't a problem with how long it takes for the port to be disabled/enabled.
– terdon♦
Feb 11 '18 at 16:38
@terdon, thanks for your answer. Do I have to create 2> /tmp/script.logfile directory or is automatically created? I don't think time is a problem, normally it takes less than 1 sec to enable/disable the port.
– Andermutu
Feb 11 '18 at 16:42
The/tmpdirectory is created by default, just add2> /tmp/script.logfileand that will create a file calledscript.logfilein/tmp. And yes, I agree that it should take less than a second but since you say it usually works, but sometimes does not, then we're looking for something strange. So maybe it sometimes takes longer.
– terdon♦
Feb 11 '18 at 16:47
Thanks @terdon. I added the script.logfile and increased the time. I will need some time to reproduce the error. I will tell you something as soon as I can.
– Andermutu
Feb 11 '18 at 16:53
1
Great! When you have more details, please edit your question and add them there (don't write "edit" or anything, just write your question as if you had included this information from the beginning). That way, the next person to read your question will have all the information.
– terdon♦
Feb 11 '18 at 17:20
|
show 4 more comments
I don't see anything obviously wrong with your script. Try adding2> /tmp/script.logfileto the end of your crontab line and see if any error output is generated when it doesn't work. You could also try increasing thesleep 510 or 20 or so, to be sure it isn't a problem with how long it takes for the port to be disabled/enabled.
– terdon♦
Feb 11 '18 at 16:38
@terdon, thanks for your answer. Do I have to create 2> /tmp/script.logfile directory or is automatically created? I don't think time is a problem, normally it takes less than 1 sec to enable/disable the port.
– Andermutu
Feb 11 '18 at 16:42
The/tmpdirectory is created by default, just add2> /tmp/script.logfileand that will create a file calledscript.logfilein/tmp. And yes, I agree that it should take less than a second but since you say it usually works, but sometimes does not, then we're looking for something strange. So maybe it sometimes takes longer.
– terdon♦
Feb 11 '18 at 16:47
Thanks @terdon. I added the script.logfile and increased the time. I will need some time to reproduce the error. I will tell you something as soon as I can.
– Andermutu
Feb 11 '18 at 16:53
1
Great! When you have more details, please edit your question and add them there (don't write "edit" or anything, just write your question as if you had included this information from the beginning). That way, the next person to read your question will have all the information.
– terdon♦
Feb 11 '18 at 17:20
I don't see anything obviously wrong with your script. Try adding
2> /tmp/script.logfile to the end of your crontab line and see if any error output is generated when it doesn't work. You could also try increasing the sleep 5 10 or 20 or so, to be sure it isn't a problem with how long it takes for the port to be disabled/enabled.– terdon♦
Feb 11 '18 at 16:38
I don't see anything obviously wrong with your script. Try adding
2> /tmp/script.logfile to the end of your crontab line and see if any error output is generated when it doesn't work. You could also try increasing the sleep 5 10 or 20 or so, to be sure it isn't a problem with how long it takes for the port to be disabled/enabled.– terdon♦
Feb 11 '18 at 16:38
@terdon, thanks for your answer. Do I have to create 2> /tmp/script.logfile directory or is automatically created? I don't think time is a problem, normally it takes less than 1 sec to enable/disable the port.
– Andermutu
Feb 11 '18 at 16:42
@terdon, thanks for your answer. Do I have to create 2> /tmp/script.logfile directory or is automatically created? I don't think time is a problem, normally it takes less than 1 sec to enable/disable the port.
– Andermutu
Feb 11 '18 at 16:42
The
/tmp directory is created by default, just add 2> /tmp/script.logfile and that will create a file called script.logfile in /tmp. And yes, I agree that it should take less than a second but since you say it usually works, but sometimes does not, then we're looking for something strange. So maybe it sometimes takes longer.– terdon♦
Feb 11 '18 at 16:47
The
/tmp directory is created by default, just add 2> /tmp/script.logfile and that will create a file called script.logfile in /tmp. And yes, I agree that it should take less than a second but since you say it usually works, but sometimes does not, then we're looking for something strange. So maybe it sometimes takes longer.– terdon♦
Feb 11 '18 at 16:47
Thanks @terdon. I added the script.logfile and increased the time. I will need some time to reproduce the error. I will tell you something as soon as I can.
– Andermutu
Feb 11 '18 at 16:53
Thanks @terdon. I added the script.logfile and increased the time. I will need some time to reproduce the error. I will tell you something as soon as I can.
– Andermutu
Feb 11 '18 at 16:53
1
1
Great! When you have more details, please edit your question and add them there (don't write "edit" or anything, just write your question as if you had included this information from the beginning). That way, the next person to read your question will have all the information.
– terdon♦
Feb 11 '18 at 17:20
Great! When you have more details, please edit your question and add them there (don't write "edit" or anything, just write your question as if you had included this information from the beginning). That way, the next person to read your question will have all the information.
– terdon♦
Feb 11 '18 at 17:20
|
show 4 more comments
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I don't see anything obviously wrong with your script. Try adding
2> /tmp/script.logfileto the end of your crontab line and see if any error output is generated when it doesn't work. You could also try increasing thesleep 510 or 20 or so, to be sure it isn't a problem with how long it takes for the port to be disabled/enabled.– terdon♦
Feb 11 '18 at 16:38
@terdon, thanks for your answer. Do I have to create 2> /tmp/script.logfile directory or is automatically created? I don't think time is a problem, normally it takes less than 1 sec to enable/disable the port.
– Andermutu
Feb 11 '18 at 16:42
The
/tmpdirectory is created by default, just add2> /tmp/script.logfileand that will create a file calledscript.logfilein/tmp. And yes, I agree that it should take less than a second but since you say it usually works, but sometimes does not, then we're looking for something strange. So maybe it sometimes takes longer.– terdon♦
Feb 11 '18 at 16:47
Thanks @terdon. I added the script.logfile and increased the time. I will need some time to reproduce the error. I will tell you something as soon as I can.
– Andermutu
Feb 11 '18 at 16:53
1
Great! When you have more details, please edit your question and add them there (don't write "edit" or anything, just write your question as if you had included this information from the beginning). That way, the next person to read your question will have all the information.
– terdon♦
Feb 11 '18 at 17:20