I ran your command and it needs more parameters. However, in your Linux system, you don't need to load the layer into GRASS. Assuming that a dataset has been created, first, you have to prepare your system to run adequately the script.
I have in my .bashrc the following lines (in this case for GRASS 6):
In my home user, I created a new version of your script (by using a lot of parameters with chaiken algorithm; where my input line was route and my output line test).
v.generalize input=route layer=1 type=line -c type=line method=chaiken threshold=1.0 look_ahead=7 reduction=50 slide=0.5 angle_thresh=3 degree_thresh=0 closeness_thresh=0 betweeness_thresh=0 alpha=1.0 beta=1.0 iterations=1 output=test
For doing executable your script you need:
chmod +x script_name
and for running it:
Finally, I have a .grassrc6 file with next lines:
After running the script at the bash console, resulting layer could be visualized at Map Canvas of QGIS: