Echo variable on each iteration of while loop

Question

I'm trying to echo the information/variables for each line of an alarmfile (named critical), using while read line to get each line of the alarmfile (might be a lot of lines on critical file):

while read line
do
{
s=`grep -Po '(?<=(sender:)).*' critical| cut -d ',' -f1` 
t=`grep -Po '(?<=(time:)).*' critical| cut -d '.' -f1` 
d=`grep -Po '(?<=(.1.3.6.1.4.1.2285.1.1.8:)).*' critical| cut -d ',' -f1` 
echo "Sender: $s" >>critical_body
echo "Time: $t" >>critical_body
echo "Description: $d" >>critical_body
}
done < critical

The output i need is to get it structured like below:

Sender:  xyz1
Time:  2021/08/11 22:14:19
Description: Lost communication with device

Sender: xyz2
Time: 2021/08/13 15:58:02
Description: Memory usage is above normal: 10% free

But i get the following, it seems that the variables values are printed all in one iteration separated with a /n and not one by one as i want.

Sender:  xyz1
 xyz2
Time:  2021/08/11 22:14:19
 2021/08/13 15:58:02
Description: Lost communication with device
Memory usage is above normal: 10% free
Sender:  xyz1
 xyz2
Time:  2021/08/11 22:14:19
 2021/08/13 15:58:02
Description: Lost communication with device
Memory usage is above normal: 10% free

Can someone help me? I am trying to find what's wrong, im relatively new on bash scripting.

cat critical
2021-08-11 22:14:19,550 INFO  [com.optimization.ems.snmp.FnTrapReceiver] raw trap record inserted: com.optimization.ems.ems.model.snmp.RawTrapid: null, oid: .1.3.6.1.4.1.2285.1.2.14, time: 2021/08/11 22:14:19.547, sender: xyz1, version: 2, varbind: .1.3.6.1.2.1.1.3.0:5d 11h 0m 35s 350ms,.1.3.6.1.6.3.1.1.4.1.0:.1.3.6.1.4.1.2285.1.2.14,.1.3.6.1.4.1.2285.1.1.6:xyz1,.1.3.6.1.4.1.2285.1.1.8:Lost communication with device,.1.3.6.1.4.1.2285.1.1.3:5,
2021-08-13 15:58:02,083 INFO  [com.optimization.ems.snmp.FnTrapReceiver] raw trap record inserted: com.optimization.ems.ems.model.snmp.RawTrapid: null, oid: .1.3.6.1.4.1.2285.1.2.3, time: 2021/08/13 15:58:02.79, sender: xyz2, version: 2, varbind: .1.3.6.1.2.1.1.3.0:98d 21h 39m 6s 60ms,.1.3.6.1.6.3.1.1.4.1.0:.1.3.6.1.4.1.2285.1.2.3,.1.3.6.1.4.1.2285.1.1.2:15:58:02 13/08/2021,.1.3.6.1.4.1.2285.1.1.3:5,.1.3.6.1.4.1.2285.1.1.8:Memory usage is above normal: 10% free,

you are processing the entirety of critical for every line and ignoring $line variable — jhnc
– jhnc, Commented Sep 6, 2021 at 10:39
@jhnc how can i make use of the $line variable inside of the loop? — Stacker123
– Stacker123, Commented Sep 6, 2021 at 11:23

Ivan · Accepted Answer · 2021-09-06 20:50:08Z

1

Something like this:

while read line; do
    time=${line/*time:/}
    time=${time/.*, sender:*/}
    sender=${line/*sender: /}
    sender=${sender/, version:*/}
    description=${line/*.1.1.8:/}
    description=${description/,*/}
    printf 'Sender: %s\nTime: %s\nDescription: %s\n\n' "$sender" "$time" "$description"
done < critical

Output will be:

Sender: xyz1
Time:  2021/08/11 22:14:19
Description: Lost communication with device

Sender: xyz2
Time:  2021/08/13 15:58:02
Description: Memory u sage is above normal: 10% free

answered Sep 6, 2021 at 20:50

Ivan

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Comments

sseLtaH · Accepted Answer · 2021-09-06 11:40:56Z

1

You can try this script. It is a bit of a hack and there may be a more efficient way to achieve this.

 for c in critical;           
    do      
    out="critical.outfile"; 
    outNew="crit.out "    ;     
    sed -E 's/.*(sender[^,]*).*/\1/1' "$c" > "$out";           
    sed -E 's/.*(time[^,]*).*/\1/' "$c" >> "$out";          
    sed -E 's/.*[0-9]:([^0-9].*[a-z]),.*/Description: \1/' "$c" >> "$out";
    awk '!r[$1]++' "$out" > $outNew;      
    echo >> $outNew;     
    awk 'r[$1]++' "$out" >> $outNew;
    cat $outNew  
done

Output

sender: xyz1
time: 2021/08/11 22:14:19.547
Description: Lost communication with device

sender: xyz2
time: 2021/08/13 15:58:02.79
Description: Memory usage is above normal: 10% free

edited Sep 6, 2021 at 11:40

answered Sep 6, 2021 at 11:25

sseLtaH

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4 Comments

Stacker123 Over a year ago

:) better but its giving me:

sender: xyz1  sender: xyz2 time: 2021/08/11 22:14:19.547 time: 2021/08/13 15:58:02.79 Description: Lost communication with device Description: Memory usage is above normal: 10% free

sseLtaH Over a year ago

Works perfectly for me. What you have there is the output of the $out variable file. I will edit my answer so there is a file with the output

Stacker123 Over a year ago

it works only when there are 2 lines, but for more lines its giving again the same

sender: xyz sender: xyz sender: xyz time: 2021/08/13 15:58:02.79 time: 2021/08/13 15:14:19.572 time: 2021/08/13 15:34:19.549 Description: Memory usage is above normal: 10% free Description: Lost communication with device Description: Lost communication with device

:(

sseLtaH Over a year ago

As mentioned, it is a bit of a hack according to the example provided. It will fail at 2+ lines due to the awk

Shaqil Ismail · Accepted Answer · 2021-09-06 11:04:27Z

0

For each line you use grep with, you can pipe to the echo command to output all in one go. Afterwards you can grep the time, and then the description. After the description you can use echo on its own to have a new line, before you start a new iteration of the loop.

For debug and troubleshoot more easily test the grep for sender sender, and see if the output is correct on the command line, then you can add this into the script, when the output for the sender is correct, the other two should be easier to amend after.

s=`grep -Po '(?<=(sender:)).*' critical| cut -d ',' -f1` | echo "Sender: $s" >>critical_body

answered Sep 6, 2021 at 11:04

Shaqil Ismail

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1 Comment

Stacker123 Over a year ago

Hello. I tried this, but it's not printing the value of the variable in one go, it only prints Sender: . im checking

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