Question

I am currently learning bash programming and dont really understand why the passing argument for me is not working.

i have a script like this

#!/bin/bash
# the following environment variables must be set before running this script
# SIM_DIR name of directory containing armsim
# TEST_DIR name of the directory containing this script and the expected outputs
# LOG_DIR name of the directory that your output is written to by the run_test2 script
# ARMSIM_VERBOSE set to "-v" for verbose logging or leave unset

# First check the environment variables are set
giveup=0
if [[ ${#SIM_DIR} -eq 0 || ${#TEST_DIR} -eq 0 || ${#LOG_DIR} -eq 0 ]] ; then
    echo One or more of the following environment variables must be set:
    echo SIM_DIR, TEST_DIR, LOG_DIR
    giveup=1
fi

# Now check the verbose flag
if [[ ${#ARMSIM_VERBOSE} != 0 && "x${ARMSIM_VERBOSE}" != "x-v" ]] ; then
    echo ARMSIM_VERBOSE must be unset, empty or set to -v
    giveup=1
fi

# Stop if environment is not set up
if [ ${giveup} -eq 1 ] ; then
    exit 0
fi

cd ${TEST_DIR}
for i in test2-*.sh; do
  echo "**** Running test ${i%.sh} *****"
  ./$i > ${LOG_DIR}/${i%.sh}.log
done

When I run the .sh file and pass in 3 example argument as below:-

$ ./run_test2 SIM_DIR TEST_DIR LOG_DIR

It still show: One or more of the following environment variables must be set:
SIM_DIR, TEST_DIR, LOG_DIR

Can anyone guide me on this? Thank you.

Answer 1

That’s not how it’s intended to work. The environment variables must be set beforehand either in the script or in the terminal like

export SIM_DIR=/home/someone/simulations
export TEST_DIR=/home/someone/tests
export LOG_DIR=/home/someone/logs

./run_test2

If you use these variables frequently, you might want to export them in ~/.bashrc. The syntax is identical to the exports in the above example.