bash script syntax error in expression

Question

In a bash script I have to find the running time of a proccess, I do it with this command:

PROCCESS_TIME=$(ps -eo pid,etimes | grep $(ps -ef | grep SCREEN | grep PROCCESS | head -1 | awk '{print $2}') | awk '{print $2}')

Which gives me running time in seconds,then I need to convert it to minutes

PROCCESS_TIME_MIN=$(( $PROCCESS_TIME / 60 ))

It works most of the time but sometimes give me this error and script exits

0 / 60 : syntax error in expression (error token is "0 / 60 ")

or:

1893 / 60 : syntax error in expression (error token is "1893 / 60 ")

Where is my problem, How to solve it?

Walter A · Accepted Answer · 2018-02-25 20:11:41Z

2

You will get that error message in this situation:

PROCCESS_TIME="0
0"
PROCCESS_TIME_MIN=$(( $PROCCESS_TIME / 60 ))

Check

PROCCESS_TIME=$(ps -eo pid,etimes | grep something | awk '{print $2}')

This can return more than 1 result. You can add |head -1 in the command, or change the awk: awk '{print $2; exit}'.
When you change your variables to lowercase, correct the spelling of proccess_time and use braces, the command will look like

process_time=$(ps -eo pid,etimes | 
   grep $(ps -ef | grep SCREEN | grep PROCCESS | awk '{print $2;exit}') |
   awk '{print $2; exit}')

I would try to change this command so that you would need 1 ps and 1 awk, but I have a different ps command (without -o etimes but with -o etime, returning time as hh:mm:ss).
Also try to use grep -E "SCREEN.*PROCCESS" or grep -E "PROCCESS.*SCREEN"

edited Feb 25, 2018 at 20:11

answered Feb 25, 2018 at 10:12

Walter A

20.2k2 gold badges29 silver badges46 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

papampi Over a year ago

I thought PROCCESS_TIME could return multiple values, and I already have the " | head -1" in it if you check. will try with exit and see how it goes. I need etimes because in next commands I have: if [[ $PROCESS_TIME -ge $MINIMUM_TIME ]] ;then ....

Walter A Over a year ago

You had 2 grep commands, and only one of those (that is used as a grep-argument) with a head -1.

papampi Over a year ago

Missed the 2nd grep, added next | head -1 and it looks like its solved. Thanks

RavinderSingh13 · Accepted Answer · 2018-02-25 08:52:32Z

0

Try using a variable for 60(I am simply giving it name as sixty, you could change it as per your need too) and try following then:

sixty=60
var=$((PROCCESS_TIME / sixty))

answered Feb 25, 2018 at 8:52

RavinderSingh13

135k14 gold badges61 silver badges100 bronze badges

1 Comment

RavinderSingh13 Over a year ago

Then you have to either show us the complete code or use set -x in starting of your script to get the traces and let us know on same.

Collectives™ on Stack Overflow

bash script syntax error in expression

2 Answers 2

3 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related