How do I read a file field-by-field under UNIX / Linux / BSD Bash shell? My sample input data file is as follows:
For each line I need to construct and execute a shell command as follows:
/path/to/deviceMaker --context=$1 -m $permissions $device2 $deviceType $major $minor
If var is defined AND NOT EMPTY, use var, otherwise set a default variable under Bash. For e.g. my script needs a parameter for output variable. It can be text or html. I set it as follows in my script
output=$1 # either text or html
However, sometime user forget to pass the parameter to my shell script and my enter logic fails. So how do I set default value to text, if no parameter passed?
Q. I can append text to a file using >> operator but how do I prepend a text to a file? I want the opposit of >> operation?