I have a problem with a script. I have a voltage meter connected to a serial USB device(ttyUSB1).
The smart meter needs an initial sequence and shortly followed by a second command to give all of it's information. That works fine. 1.8.0*00(000898.46) for example comes in this is the line I am interested in. The number in brackets is the kWh number i want. If i open a second terminal and do a cat /dev/ttyUSB1 it works fine and i can see the information coming in. After 4 to 5 seconds the line I want comes in. But the script is not working. If i start a script in one terminal it keeps waiting. Grep is not finishing. If I start it in a second terminal then the first terminal gets finished. Or just the grep 1.8.0 /dev/ttyUSB1 -m1 in another terminal works but not in the script.
I tried different methos with read and so none worked. To be honest i don't understand much of scripting and always succeed somehow but here nothings helped :(
Please help. Thank you!
Arne
here the script:
#! /bin/bash
echo start
echo $'\x2f\x3f\x21\x0d' > /dev/ttyUSB1
sleep 1
echo ask
echo $'\x06\x30\x30\x30\x0d' > /dev/ttyUSB1
echo wait
grep 1.8.0 /dev/ttyUSB1 -m1
echo end
You can try creating a file with voltimeter's output and grep from that file:
#! /bin/bash
dev=/dev/ttyUSB1
file=/tmp/testfile
(tail -f $dev | tee $file) & # let's continuously copy in background
echo start
echo $'\x2f\x3f\x21\x0d' > $dev
sleep 1
echo ask
echo $'\x06\x30\x30\x30\x0d' > $dev
echo wait
grep 1.8.0 $file # lets get the info from the file instead
echo end
sleep 1
exit
Related
I have script with name : run.sh
This is my script code :
#!/usr/bin/env bash
install() {
sudo apt-get update
sudo apt-get upgrade
}
if [ "$1" = "install" ]; then
install
else
if [ ! -f ./tg/tgcli ]; then
echo "tg not found"
echo "Run $0 install"
exit 1
fi
#sudo service redis-server restart
#./tg/tgcli -s ./bot/bot.lua -l 1 -E $#
./tg/tgcli -s ./bot/bot.lua $#
fi
and when run this script give me output like this every second :
[09:54] 2014 Hello
[09:55] 2014 Hi
[09:57] 2014 How Are you ?
and many like this (thousands in hour !)
and my server get slow in 5 hour.
i check print commands in bot.lua but there are no way to remove print it.
can you add some codes to clear my script logs every 10 second ?
Thanks a lot.
My Script Output Doesn't Save Anywhere and Just Show me in terminal
I want a code such as clear command on linux terminal , clear my script logs every 10 minute or 5 minute.
After 5 day of script running i can (sometimes can't) login my server and my server get very slow and i must wait 3 or 5 minute to login my server and this amazing after login my server my server again get fast !
and i forgot say i use byobu screen for run my scripts and I think screen get my server slow down.
I don't think that something as simple as this would cause your server to slow down, but you can add a check to your script to calculate the size or line count of your log file every time it runs.
This function assumes you are redirecting your output to a log file. Set the variables to whatever makes the most sense.
log_check() {
line_count=$(wc -l $log_file | awk '{print $1}')
size_check=$(du -ax $log_file | awk '{print $1}')
max_file_size="1500"
max_file_length="1000"
if [[ $line_count >= $max_file_length || $size_check >= $max_file_size ]]; then
echo "" > $log_file
fi
}
I would also recommend using [[ ]] over [ ] since this is a bash script, as long as you don't plan in it being posix compliant and only plan on using it with bash [[]] is always better than [].
EDIT:
Since you are logging output to the terminal and not a file you can literally use the clear command in your script.
Try this out and see how the functionality works
for i in {1..20}; do
echo $i
if (( i == 10 )); then
clear
fi
done
I'm assuming your code has a loop somewhere, if not it will be a bit more complex to clear the terminal session. I'm not really sure what part of your code is actually printing anything to stdout, I'm guessing it's this piece here
./tg/tgcli -s ./bot/bot.lua $#
You could try something like this, which will background your initial process and then run clear every 60 seconds to clear the terminal window. Is there any reason you're not writing the output to a log file? That alone could solve some of your issues as well.
#!/bin/bash
./tg/tgcli -s ./bot/bot.lua $# &
pid="$!"
check_pid() {
ps -ef |grep "$pid"|grep -v 'grep' &>/dev/null
}
cnt=1
until ! check_pid; do
if (( cnt == 6 )); then
clear
cnt=1
fi
sleep 10
((cnt++))
done
I'm working on an optimization and for that I need to link a matlab code into a linux program and keep monitoring the outputs. I'd done this link using this sh below, however it wasn't working well, since I couldn't keep track of more than one 'expression'.
#!/bin/bash
../program inputfile &> OutputFile.dat &
tail -f OutputFile.dat | sed -n '/NaN/q;/STOP/q'
killall program
I've asked for help here, and I got a good solution. The solution solved partially the problem. Running the program on the prompt it was possible to keep track on those expressions and kill the program when needed. The solution given was:
#!/bin/bash
( stdbuf -o 0 -e 0 ../program inputfile & ) &> OutputFile.dat
sed -n '/NaN/q;/STOP/q' <(tail -f OutputFile.dat)
killall program
When I implemented on the matlab, and did the 'linkage' the code didn't responded well. After a few minutes running, the matlab got stuck, I couldn't get any answer from the terminal. When looked manually on the outputs of my program I realized that there were no problems on the program, and the outputs was normally being written.
I can't solve this problem. I don't have a lot of experience on sh. I've searched for answers, but I couldn't find any. Alternative suggestions to achieve the same thing are also welcome.
Thanks in advance
The tail -f is causing the hang. You need to also kill the sed/tail process in order to continue.
#!/bin/bash
( stdbuf -o 0 -e 0 ../program inputfile & ) &> OutputFile.dat
# get the process id (pid) of "program"
# (bash sets $! to the pid of the last background process)
program_pid=$!
# put this in the background, too
sed -n '/NaN/q;/STOP/q' <(tail -f OutputFile.dat) &
# get its pid
sed_pid=$!
# wait while "program" and sed are both still running
while ps -p $program_pid && ps -p $sed_pid; do
sleep 1
done >/dev/null
# one (or both) have now ended
if ps -p $program_pid >/dev/null; then
# "program" is still running, and sed must have found a match and ended
echo "found Nan or STOP; killing program"
kill $program_pid
elif ps -p $sed_pid; then
# sed is still running, so program must have finished ok
kill $sed_pid
fi
ref: https://stackoverflow.com/a/2041505/1563960
So I am running into a problem with unix scripts that use curl to make rest calls. I have one script, that runs two other scripts inside of it.
cat example.sh
FILE="file1.txt"
RECIP="wilfred#blamagam.com"
rm -f $FILE
./script1.sh > $FILE
mail -s "subject" $RECIP < $FILE
RECIP="bob#blamagam.com"
rm -f $FILE
./script2.sh > $FILE
mail -s "subject" $RECIP < $FILE
exit 0
Each script makes rest calls to the same service. It is my understanding that script1.sh should completely finish before script2.sh is ran, however that is not the case. In the logs for the rest service I see a rest call from the second script in the middle of the first one still executing. The second script then fails because of this (it does not get any data returned).
I am modifying this process so I am not the one who originally wrote it. I am not seeing any forked processes, or background processes at all and I have been banging my head against the wall.
I do know that script2.sh works. Whenever script1.sh takes under a minute script2.sh works just fine, but more often than not script1.sh takes over a min, causing the second script to fail.
This is ran by a cron, and the contents of the files are mailed out, so I cant just default to running them manually. Any suggestions for what to look into would be much appreciated!
EDIT: Here is a high pseudo code example
script1.sh
ITEMS=`/usr/bin/curl -m 10 -k -u userName:passWord -L https://server/rest-service/rest?where=clause=value;clause2=value2&sel=field 2>/dev/null | sed s/<\/\?Attribute[^>]*>/\n/g | grep -v '^<' | grep -v '^$' | sed 's/ //g'`
echo "\n Subject for these metrics"
echo "$ITEMS"
Both scripts have lots of entries like this. There are 2 or 3 for loops but they are simple and I do not see any background processes being called. Its a large script so I could only provide a snippet. Could the rest call into pipes be causing an issue?
Edit:
Just tested this on my system and it seems to work.
cat example.sh
FILE="file1.txt"
RECIP="wilfred#blamagam.com"
rm -f "$FILE"
(./script1.sh > "$FILE") &
procscript1=$!
wait "$procscript1"
mail -s "subject" "$RECIP" < "$FILE"
RECIP="bob#blamagam.com"
rm -f "$FILE"
(./script2.sh > "$FILE") &
procscript2=$!
wait "$procscript2"
mail -s "subject" "$RECIP" < "$FILE"
exit 0
Put the script executions in the background with the &.
Get the process id's for each script execution.
Use the wait command to block until the execution is done.
I am having great difficulty in understanding what shows up on ps command. To test my understanding I created below dummy script
#!/bin/bash
for i in {1..100000}
do
date -u
date -u
date -u
done
while running this script I opened a new terminal and executed repeatedly
ps -eaf | grep date | grep -v grep
and I was able to date process in the output.
I later changed dummy script by replacing date -u with echo "what is going on"
#!/bin/bash
for i in {1..100000}
do
echo "What is going on"
echo "What is going on"
echo "What is going on"
done
while running the updated dummy script, I opened a new terminal and executed repeatedly
ps -eaf | grep echo | grep -v grep
and echo was never shown in output. Why is this? I suspect the reason is the script being a bash script, may be it is using builtin echo therefore it was not displayed in ps output. Am I correct? What am I missing here?
echo is a builtin in bash:
$ type echo
echo is a shell builtin
That means that a new process is not created when echo is run. All the work is done by the bash process instead, which is way more efficient.
You can run the non-builtin echo explicitly:
command echo "What is going on"
This forks and execs /bin/echo instead, letting it show up in ps.
I'm trying to have a lightweight memory profiler for the matlab jobs that are run on my machine. There is either one or zero matlab job instance, but its process id changes frequently (since it is actually called by another script).
So here is the bash script that I put together to log memory usage:
#!/bin/bash
pid=`ps aux | grep '[M]ATLAB' | awk '{print $2}'`
if [[ -n $pid ]]
then
\grep VmSize /proc/$pid/status
else
echo "no pid"
fi
when I run this script in bash like this:
./script.sh
it works fine, giving me the following result:
VmSize: 1289004 kB
which is exactly what I want.
Now, I want to run this periodically. So I run it with watch, like this:
watch ./script.sh
But in this case I only receive:
no pid
Please note that I know the matlab job is still running, because I can see it with the same pid on top, and besides, I know each matlab job take several hours to finish.
I'm pretty sure that something is wrong with the quotes I have when setting pid. I just can't figure out how to fix it. Anyone knows what I'm doing wrong?
PS.
In the man page of watch, it says that commands are executed by sh -c. I did run my script like sh -c ./script and it works just fine, but watch doesn't.
Why don't you use a loop with sleep command instead?
For example:
#!/bin/bash
pid=`ps aux | grep '[M]ATLAB' | awk '{print $2}'`
while [ "1" ]
do
if [[ -n $pid ]]
then
\grep VmSize /proc/$pid/status
else
echo "no pid"
fi
sleep 10
done
Here the script sleeps(waits) for 10 seconds. You can set the interval you need changing the sleep command. For example to make the script sleep for an hour use sleep 1h.
To exit the script press Ctrl - C
This
pid=`ps aux | grep '[M]ATLAB' | awk '{print $2}'`
could be changed to:
pid=$(pidof MATLAB)
I have no idea why it's not working in watch but you could use a cron job and make the script log to a file like so:
#!/bin/bash
pid=$(pidof MATLAB) # Just to follow previously given advice :)
if [[ -n $pid ]]
then
echo "$(date): $(\grep VmSize /proc/$pid/status)" >> logfile
else
echo "$(date): no pid" >> logfile
fi
You'd of course have to create logfile with touch.
You might try just running ps command in watch. I have had issues in the past with watch chopping lines and such when they get too long.
It can be fixed by making the terminal you are running the command from wider or changing the column like this (may need to adjust the 160 to your liking):
export COLUMNS=160;