Using new_script will save you a lot of work by creating a customized template incorporating a parser for your script's command-line options and arguments. The template also includes a number of useful housekeeping routines such as error and signal handlers. The generated script is fully functional (though it does nothing) and is ready for you to insert your program-specific logic.
Synopsis
new_script [-h|--help] [-q|--quiet] [-s|--root] [script]
Description
new_script will, by default, prompt the user for details about the script to be generated:
Enter script output filename >
Choose a name for the generated script file.
Enter purpose of script >
Enter a one-line description of the script.
Include GPL license header [y/n]? >
Entering "y" will insert a GPL license header into the comment block at the beginning of the script.
Does this script require superuser privileges [y/n]? >
Entering "y" will insert a routine that verifies the user has superuser privileges before allowing the script to execute.
Does this script support command-line options [y/n]? >
If you intend to support command-line options for your script, answer "y".
Option 1:
Enter option letter [a-z] (Enter to end) >
If command line options are desired, a series of prompts will appear. First, you will be asked for the short (single letter) form of the option. Enter a letter in the range of a-z to define the option or enter nothing to end the option input loop.
Description of option ------------------->
Enter a short description of the option. This will be used in the "help" message.
Enter long alternate name (optional) ---->
Enter a single-word long option name if desired. For example, if you have an option "h" for a help function, you can specify an alternate long form name for the option such as "help." When your script is executed, you can invoke the help function by including either -h or --help on the command-line.
Note that new_script always includes the "h" and "help" options automatically by default.
Enter option argument (if any) ---------->
If your option requires an argument, enter a single-word descriptor here. For example, if you were creating a script named my_script supporting both an input and an output file, you might have an option for each with their corresponding arguments such as:
my_script -i infile -o outfile
After you finish entering your option information, new_script will generate your custom script template.
Your script will contain a handy error handling routine called error_exit, which is used like this:
error_exit error_message
where error_message is a string containing a descriptive error message. The error_exit function outputs the error_message string to standard error, calls the clean_up function to perform any necessary housekeeping, then exits with an exit status of 1. Here is an example:
error_exit "Something bad happened!"
You can see other examples within the new_script code itself.
Options
The new_script program supports the following command-line options:
-h, --help
Display a help message and exit.
-q, --quiet
Quiet mode. Do not prompt user for script information and output default script to standard output.
-s, --root
Require superuser privileges for execution of generated script.
You may also include the desired file name for the generated script on the command-line after any specified options.
Installation
You can find the script here. To install it, just highlight the text and copy it into a text editor and save the resulting file. If you're feeling clever, you can directly write it to a file via the command-line. Highlight the text as before, open a terminal and enter the following command (assuming you have a bin directory in your home directory, otherwise adjust as needed):
cat > ~/bin/new_script
Paste the script into the terminal by clicking the middle mouse button and type Ctrl-d.
Once you have written the script, give it execute permissions like so:
chmod +x ~/bin/new_script
Posts
No comments:
Post a Comment