Working with command line arguments (special variables, set and shift, getopt)
Command line arguments are required for the following reasons:
- They inform the utility or command as to which file or group of files to process (reading/writing of files)
- Command line arguments tell the command/utility which option to use
Check the following command line:
student@ubuntu:~$ my_program arg1 arg2 arg3
If my_command
is a bash Shell script, then we can access every command line positional parameters inside the script as follows:
$0 would contain "my_program" # Command $1 would contain "arg1" # First parameter $2 would contain "arg2" # Second parameter $3 would contain "arg3" # Third parameter
The following is the summary of positional parameters:
$0 |
Shell script ... |
Get Learning Linux Shell Scripting now with O’Reilly online learning.
O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.