"Not a valid identifier" on file read

Question

In a Putty remote connection, I am trying to read a file line by line, cut each line by delimiter (";"), and run a command if the variables satisfy a condition. However, I get "not a valid identifier" upon reading the file.

Just some simple logic in the test.sh file:

while read download.archive
do
    likes = $(echo cut -d ";" -f 1 $line)
    echo $likes
    dislikes = $(echo cut -d ";" -f 2 $line)
    dislikes = $((dislikes * 95))
    url = $(echo cut -d ";" -f 3 $line)

if [$likes -gt $dislikes]
then
    youtube-dl --config-location youtube-dl-3.conf url
fi

done < download.archive

The download.archive file reads as follows-

9873;354;https://www.youtube.com/watch?v=0fd56CGnVRU
3267;54;https://www.youtube.com/watch?v=Mq4jAwPdCMw
25411;871;https://www.youtube.com/watch?v=PcSBOUpgngM
2829;44;https://www.youtube.com/watch?v=S-rj8m7Ssow
921;303;https://www.youtube.com/watch?v=JchVQMuxRVA
2014;32;https://www.youtube.com/watch?v=H8Y_ZfNViPU

Yet when I try to run ./test.sh, I get "./test.sh: line 4: read: 'download.archive': not a valid identifier". If the file is valid, why is it throwing an error?

Answer 1

After numerous errors, here is the working code:

while IFS= read -r line; do

    likes=$(cut -d ";" -f 1 <<< "$line")
    dislikes=$(cut -d ";" -f 2 <<< "$line")
    likes=$((likes / 50))
    url=$(cut -d ";" -f 3 <<< "$line")

if [ $likes -gt $dislikes ]
then
    youtube-dl --config-location youtube-dl-3.conf $url
fi

done < download.archive

The "read" command's first line is always like the above (read line), and the file to be read is after the "done" statement at the end (done < download.archive). This post here explains the IFS and -r additions, and what they do.

When assigning variable, I guess you can't put a space between the assignment. As such, this doesn't work

likes = $(cut -d ";" -f 1 $line)

But this does:

likes=$(cut -d ";" -f 1 $line)

...Except, to refer to the line the program is currently reading, we must use <<<. Like this:

likes=$(cut -d ";" -f 1 <<< $line)

Lastly, when checking for a condition (in the if statement), there needs to be a space between both the beginning and ending brackets, and the condition inside, like so -

if [ $likes -gt $dislikes ]

To refer to the variable url that holds our url for youtube-dl, we refer to variables using a $. Like this:

$url