CODEWITHSUNDEEP
bashgrep
user3447273
user3447273

Reputation: 361

Pgrep conditional statement syntax

If doing an if-then statement in a bash script, like this, where:

if [ "$pgrep foo_process" ] > 0; then
other foo
fi

When the foo_process is running, the above if-statement should result in a true result, since the pid returned by 

pgrep foo_process

will be greater than zero. But the below "do while" script, it is not detecting when the foo_process is stopped.

#!/bin/bash
if [ "$pgrep foo_process" ] > 0; then
    while [ "$pgrep foo_process" ] > 0; do
        /home/scripts/arttst.sh
        sleep 2  
    done
else
fi
exit 4

Why?

Even when using a pgrep syntax to get a binary output (either 0 or 1), it still will not work:

#!/bin/bash
#pgrep foo_process
if [ "$pgrep -f foo_process  &> /dev/null ; echo $?" ] = 0; then
    while [ "$pgrep -f foo_process  &> /dev/null ; echo $?" ] = 0; do
        bash /home/script/arttst.sh
        sleep 2  
    done
else
exit 4
fi
exit 4

Upvotes: 0

Views: 1048

Answers (1)

user3447273
user3447273

Reputation: 361

Solved using pgrep with the -x switch:

if pgrep -x "foo_process" > /dev/null; then
    while pgrep -x "foo_process" > /dev/null; do
      bash /home/scripts/arttst.sh
      sleep 2 
      pgrep -x "foo_process" > /dev/null
    done  
else
fi
exit 4

Upvotes: 1

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