CODEWITHSUNDEEP
shell
Mohamed Mostafa
Mohamed Mostafa

Reputation: 1

Handle exception in do statement

Please, I am trying to create the below script:

..
do
PID=$(echo $i | cut -d: -f1)
THREADS=$(cat /proc/$PID/status | grep -i "Threads" | awk '{print $2}')
done
..

But sometimes, there are processes that do not have such file status created. So, how can I handle such exception as I am getting this message while executing the script

$ ./check_memory.sh cat: /proc/9809/status: No such file or directory $

So, I need to print this message as follows:

Memory Usage Per Process
----------------------------------------
PID       THREADS                                              
9936      129                                                       
9809      There is no status file for this process

Appreciate your support!

Appreciate your support, please

Upvotes: 0

Views: 35

Answers (1)

Gilles Quénot
Gilles Quénot

Reputation: 185025

You can use this sh script:

#!/bin/sh

cat<<EOF
Memory Usage Per Process
----------------------------------------
PID     THREADS
EOF

for pid in 999 $$; do
    threads=$(awk '/Threads/{print $2}' "/proc/$pid/status" 2>/dev/null) ||
    threads='There is no status file for this process'
    printf '%b\n' "$pid\t$threads"
done

Output:

Memory Usage Per Process
----------------------------------------
PID       THREADS
999       There is no status file for this process
345234    1

Edited script from question in comments

#!/bin/sh

printf "%-10s%-10s%s\n" "PID" "THREADS"

function sysmon_main() {
    pids=( $(ps -o pid ax | awk 'NR>1') )
    for pid in "${pids[@]}"; do
        threads=$(awk '/Threads/{print $2}' "/proc/$pid/status" 2>/dev/null) ||
        threads='There is no status file for this process'
        printf "%-10s%-10s%s\n" "$pid" "$threads"
    done
}
sysmon_main | sort -bnr -k2

Upvotes: 2

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