[SOLVED] Execute a particular command only for the first time in a shell

Issue

I have a script.
I need to execute a particular command only for the first time i try to run this script in my shell. Otherwise, it should not be executed and the rest of the commands should be done.

How can i implement this? All pointers are welcome.

Thanks,
Sen

---

This is a code which i tried to implement :

start_time=`date +%s`
echo $script_instance
if [ `echo $script_instance` == true ]; then
  end_time=`date +%s`
  echo '#########################################################################'
  echo '# Build Date : '`date`
  echo '# Compilation time : '`expr $end_time - $start_time` s
  echo '#########################################################################'
else
  echo '-------------------------------------------------------------------------'
  echo 'Updating the APIs'
  echo '-------------------------------------------------------------------------'
fi
script_instance=true
export $script_instance

---

This is not working correctly. Please correct me if I am wrong somewhere.

Solution

You can set an environment variable the first time you're running the script:

• csh/tcsh: setenv MYVARIABLE something
• bash: export MYVARIABLE="something"

Then check with an if-clause if the variable is set. If so, do the other stuff, if not then this is the first time the script is executed.

Answered By - dertkw

Answer Checked By - Senaida (WPSolving Volunteer)