Linux shell scripting - assigning tail value to a variable?

Question

I'm setting up a shell script that reads the last line of a log file using:

tail -1 "/path/to/gdscript.log"

.. which is echo'ing the last line of the script just fine. The last line of the log dictates whether the process succeeded or failed, so I'm trying to run a quick echo as follows (this is the bit I'm failing at):

if [ (tail -1 "/path/to/gdscript.log")  == "Process Complete" ]; then
echo "Data Transfer OK"
else
echo "Data Transfer Failed"
exit 1
fi

.. but using the script above I'm getting:

./gdscript.sh: line 14: syntax error near unexpected token `tail'

Can someone in the know show me how to format the IF gate above so that I can work off the last line of the log file? I'm new to shell scripting and would really appreciate the help.

Thanks, Paul G

Answer 1

To get the output of a command you need $(cmd...) . So I think you mean:

if [ "$(tail -1 '/path/to/gdscript.log')"  == "Process Complete" ]; then
...

Answer 2

您应该使用：
if [ $(tail -1 /path/to/gdscript.log) == "Process Complete" ]; then