Unable to break out of While loop - bash

Question

I would like to break out of a loop when it gets to a blank line in a file. The issue is that my regexp's used to condition my data create a line with characters so I need something from the beginning to check if a line is empty or not so I can break out. What am I missing?
#!/bin/bash
#NOTES: chmod this script with chmod 755 to run as regular local user
#This line allows for passing in a source file as an argument to the script (i.e: ./script.sh source_file.txt)
input_file="$1"
#This creates the folder structure used to mount the SMB Share and copy the assets over to the local machines
SOURCE_FILES_ROOT_DIR="${HOME}/operations/source"
DESTINATION_FILES_ROOT_DIR="${HOME}/operations/copied_files"
#This creates the fileshare mount point and place to copy files over to on the local machine.
echo "Creating initial folders..."
mkdir -p "${SOURCE_FILES_ROOT_DIR}"
mkdir -p "${DESTINATION_FILES_ROOT_DIR}"
echo "Folders Created! Destination files will be copied to ${DESTINATION_FILES_ROOT_DIR}/SHARE_NAME"
while read -r line;
do
if [ -n "$line" ]; then
continue
fi
line=${line/\\\\///}
line=${line//\\//}
line=${line%%\"*\"}
SERVER_NAME=$(echo "$line" | cut -d / -f 4);
SHARE_NAME=$(echo "$line" | cut -d / -f 5);
ASSET_LOC=$(echo "$line" | cut -d / -f 6-);
SMB_MOUNT_PATH="//$(whoami)#${SERVER_NAME}/${SHARE_NAME}";
if df -h | grep -q "${SMB_MOUNT_PATH}"; then
echo "${SHARE_NAME} is already mounted. Copying files..."
else
echo "Mounting it"
mount_smbfs "${SMB_MOUNT_PATH}" "${SOURCE_FILES_ROOT_DIR}"
fi
cp -a ${SOURCE_FILES_ROOT_DIR}/${ASSET_LOC} ${DESTINATION_FILES_ROOT_DIR}
done < $input_file
# cleanup
hdiutil unmount ${SOURCE_FILES_ROOT_DIR}
exit 0
Expected result was for the script to realize when it gets to a blank line and then stops. The script works works when i remove the
if [ -n "$line" ]; then
continue
fi
The script runs and pulls assets but just keeps on going and never breaks out. When I do it as is now I get :
Creating initial folders...
Folders Created! Destination files will be copied to /Users/baguiar/operations/copied_files
Mounting it
mount_smbfs: server connection failed: No route to host
hdiutil: unmount: "/Users/baguiar/operations/source" failed to unmount due to error 16.
hdiutil: unmount failed - Resource busy

Answer 1

cat test.txt
This is some file
There are lines in it
And empty lines
etc
while read -r line; do
if [[ -n "$line" ]]; then
continue
fi
echo "$line"
done < "test.txt"
will print out
That's because -n matches strings that are not null, i.e., non-empty.
It sounds like you have a misunderstanding of what continue means. It does not mean "continue on in this step of the loop", it means "continue to the next step of the loop", i.e., go to the top of the while loop and run it starting with the next line in the file.
Right now, your script says "go line by line, and if the line is not empty, skip the rest of the processing". I think your goal is actually "go line by line, and if the line is empty, skip the rest of the processing". This would be achieved by if [[ -z "$line" ]]; then continue; fi
TL;DR You are skipping all the non-empty lines. Use -z to check if your variable is empty instead of -n.