This follows on from Faulty tail syntax or grep command? but I'm reading a live log entries for given conditions and when they're met continuing the execution of the rest of the script. I'm using this:
tail -Fn0 /var/log/messages | grep -q "CPU utilization" | grep -q "exceeded threshold"
FPC=$(echo $line | awk 'END { print substr($8,1,1) }')
PIC=$(echo $line | awk 'END { print substr($11,1,1) }')
echo FPC $FPC
echo PIC $PIC
echo "Running information gathering"...and rest of script.
Which works perfectly for the conditions detection and further execution, but I don't have the log entry to test for the FPC and PIC variables. I've tried wrapping the tail statement thus:
line=$(tail -Fn0 /var/log/messages | grep -q "CPU utilization" | grep -q "exceeded threshold")
but grep -q exits silently and the $line variable is blank. I've tried:
line=$(tail -Fn0 /var/log/messages | grep -m1 "CPU utilization" | grep -m1 "exceeded threshold")
which doesn't work until I attempt to CONTROL-C out of the script. Then it works fine and continues perfectly. Can someone help please?
I need the variables FPC and PIC later in the script.
Assuming that you don't need these variables later on, you could do something like this:
tail -Fn0 /var/log/messages | \
awk '/CPU utilization/ && /exceeded threshold/ {
print "FPC", substr($8,1,1); print "PIC", substr($11,1,1); exit }'
When the line matches both patterns, print the two parts of it that you are interested in and exit.
If you do need the variables, you could do something like this instead:
line=$(tail -Fn0 /var/log/messages | awk '/CPU utilization/&&/exceeded threshold/{print;exit}')
FPC=$(echo "$line" | awk '{ print substr($8,1,1) }')
PIC=$(echo "$line" | awk '{ print substr($11,1,1) }')
Related
I have a bash script as below:
curl -s "$url" | grep "https://cdn" | tail -n 1 | awk -F[\",] '{print $2}'
which is working fine, when i run run it, i able to get the cdn url as:
https://cdn.some-domain.com/some-result/
when i put it as variable :
myvariable=$(curl -s "$url" | grep "https://cdn" | tail -n 1 | awk -F[\",] '{print $2}')
and i echo it like this:
echo "CDN URL: '$myvariable'"
i get blank result. CDN URL:
any idea what could be wrong? thanks
If your curl command produces a trailing DOS carriage return, that will botch the output, though not exactly like you describe. Still, maybe try this.
myvariable=$(curl -s "$url" | awk -F[\",] '/https:\/\/cdn/{ sub(/\r/, ""); url=$2} END { print url }')
Notice also how I refactored the grep and the tail (and now also tr -d '\r') into the Awk command. Tangentially, see useless use of grep.
The result could be blank if there's only one item after awk's split.
You might try grep -o to only return the matched string:
myvariable=$(curl -s "$url" | grep -oP 'https://cdn.*?[",].*' | tail -n 1 | awk -F[\",] '{print $2}')
echo "$myvariable"
I have a simple script that checks the process id of some process using ps. When I run it directly on command line, it works fine but does not when I run it in a script. What am I doing wrong?
This works fine:
ps auwx | grep elasticsearch | grep -v grep | grep user | awk '{print $2}' | tail -1
In script, it does not:
#!/bin/bash
#Setting ES Heap to 50GB
ES_HEAP_SIZE="50g"
#Finding dump file to be deleted
FILE_ID=$(ps auwx | grep elasticsearch | grep -v grep | grep user | awk '{print $2}' | tail -1)
FILE_NAME="java_pid$FILE_ID.hprof"
echo "Elasticsearch pid: $FILE_ID"
echo "Dump file name if it exists: $FILE_NAME. Checking now."
if [ -s $FILE_NAME ]
then
rm $FILE_NAME
kill -9 $FILE_ID
#Starting elasticsearch daemon
/data/elasticsearch-1.4.4/bin/elasticsearch -d
else
echo "All good. Dump file $FILE_NAME does not exist."
fi
Personal pet peeve: why do you have six executions in your pipeline when two will handle everything you need?
ps auwx | awk '/elasticsearch/ && /user/ { x=$2 } END{ print x; }'
As an aside, you wanted PID? Because it looks like you're reading PPID.
Hope that helps.
I have a command I'm using to get the hostname.localdomain:
dig axfr #dc1.localdomain.com localdomain.com | grep -i Lawler | awk '{ getline ; $1=substr($1,1,length($1)-1); print $1 ; exit }'
This nicely returns a result like:
michael.lawler.localdomain.com
I'd like to further use that result as a variable in a Bash script.
It seems I'm having trouble getting past the first pipe.
If I VAR="dig axfr #dc1.localdomain.com localdomain.com | grep -i Lawler | awk '{ getline ; $1=substr($1,1,length($1)-1); print $1 ; exit }'"
...I get back the entire zone transfer. I've also tried many minor changes, adding $ before the dig command, without quotes, but nothing seems to work. How can I fix this?
VAR=$( dig axfr #dc1.localdomain.com localdomain.com |
grep -i Lawler |
awk '{ getline ; $1=substr($1,1,length($1)-1); print $1 ; exit }' )
Use backtics instead of quotes:
VAR=`dig axfr #dc1.localdomain.com localdomain.com | grep -i Lawler | awk '{ getline ; $1=substr($1,1,length($1)-1); print $1 ; exit }'`
Backtics actually mean "run whatever is in here and return standard out as the expression's value", but quotes don't do that.
My bash script is:
output=$(curl -s http://www.espncricinfo.com/england-v-south-africa-2012/engine/current/match/534225.html | sed -nr 's/.*<title>(.*?)<\/title>.*/\1/p')
score=echo"$output" | awk '{print $1}'
echo $score
The above script prints just a newline in my console whereas my required output is
$ curl -s http://www.espncricinfo.com/england-v-south-africa-2012/engine/current/match/534225.html | sed -nr 's/.*<title>(.*
?)<\/title>.*/\1/p' | awk '{print $1}'
SA
So, why am I not getting the output from my bash script whereas it works fine in terminal am I using echo"$output" in the wrong way.
#!/bin/bash
output=$(curl -s http://www.espncricinfo.com/england-v-south-africa-2012/engine/current/match/534225.html | sed -nr 's/.*<title>(.*?)<\/title>.*/\1/p')
score=$( echo "$output" | awk '{ print $1 }' )
echo "$score"
Score variable was probably empty, since your syntax was wrong.
I am developing a script on a Solaris 10 SPARC machine to calculate how many patches got installed successfully during a patch delivery. I would like to display to the user:
(X) of 33 patches were successfully installed
I would like my script to output dynamically replacing the "X" so the user knows there is activity occurring; sort of like a counter. I am able to show counts, but only on a new line. How can I make the brackets update dynamically as the script performs its checks? Don't worry about the "pass/fail" ... I am mainly concerned with making my output update in the bracket.
for x in `cat ${PATCHLIST}`
do
if ( showrev -p $x | grep $x > /dev/null 2>&1 ); then
touch /tmp/patchcheck/* | echo "pass" >> /tmp/patchcheck/$x
wc /tmp/patchcheck/* | tail -1 | awk '{print $1}'
else
touch /tmp/patchcheck/* | echo "fail" >> /tmp/patchcheck/$x
wc /tmp/patchcheck/* | tail -1 | awk '{print $1}'
fi
done
The usual way to do that is to emit a \r carriage return (CR) at some point and to omit the \n newline or line feed (LF) at the end of the line. Since you're using awk, you can try:
awk '{printf "\r%s", $1} END {print ""}'
For most lines, it outputs a carriage return and the data in field 1 (without a newline at the end). At the end of the input, it prints an empty string followed by a newline.
One other possibility is that you should place the awk script outside your for loop:
for x in `cat ${PATCHLIST}`
do
if ( showrev -p $x | grep $x > /dev/null 2>&1 ); then
touch /tmp/patchcheck/* | echo "pass" >> /tmp/patchcheck/$x
wc /tmp/patchcheck/* | tail -1
else
touch /tmp/patchcheck/* | echo "fail" >> /tmp/patchcheck/$x
wc /tmp/patchcheck/* | tail -1
fi
done | awk '{ printf "\r%s", $1} END { print "" }'
I'm not sure but I think you can apply similar streamlining to the rest of the repetitious code in the script:
for x in `cat ${PATCHLIST}`
do
if showrev -p $x | grep -s $x
then echo "pass"
else echo "fail"
fi >> /tmp/patchcheck/$x
wc /tmp/patchcheck/* | tail -1
done | awk '{ printf "\r%s", $1} END { print "" }'
This eliminates the touch (which doesn't seem to do much), and especially not when the empty output of touch is piped to echo which ignores its standard input. It eliminates the sub-shell in the if line; it uses the -s option of grep to keep it quiet.
I'm still a bit dubious about the wc line. I think you're looking to count the number of files, in effect, since each file should contain one line (pass or fail), unless you listed some patch twice in the file identified by ${PATCHLIST}. In which case, I'd probably use:
for x in `cat ${PATCHLIST}`
do
if showrev -p $x | grep -s $x
then echo "pass"
else echo "fail"
fi >> /tmp/patchcheck/$x
ls /tmp/patchcheck | wc -l
done | awk '{ printf "\r%s", $1} END { print "" }'
This lists the files in /tmp/patchcheck and counts the number of lines output. It means you could simply print $0 in the awk script since $0 and $1 are the same. To the extent efficiency matters (not a lot), this is more efficient because ls only scans a directory, rather than having wc open each file. But it is more particularly a more accurate description of what you are trying to do. If you later want to count the passes, you can use:
for x in `cat ${PATCHLIST}`
do
if showrev -p $x | grep -s $x
then echo "pass"
else echo "fail"
fi >> /tmp/patchcheck/$x
grep '^pass$' /tmp/patchcheck/* | wc -l
done | awk '{ printf "\r%s", $1} END { print "" }'
Of course, this goes back to reading each file, but you're getting more refined information out of it now (and that's the penalty for the more refined information).
Here is how I got my patch installation script working the way I wanted:
while read pkgline
do
patchadd -d ${pkgline} >> /var/log/patch_install.log 2>&1
# Create audit file for progress indicator
for x in ${pkgline}
do
if ( showrev -p ${x} | grep -i ${x} > /dev/null 2>&1 ); then
echo "${x}" >> /tmp/pass
else
echo "${x}" >> /tmp/fail
fi
done
# Progress indicator
for y in `wc -l /tmp/pass | awk '{print $1}'`
do
printf "\r${y} out of `wc -l /patchdir/master | awk '{print $1}'` packages installed for `hostname`. Last patch installed: (${pkgline})"
done
done < /patchdir/master