Using getopts to process long and short command line options

Question

I wish to have long and short forms of command line options invoked using my shell script.

I know that getopts can be used, but like in Perl, I have not

Answer 1

Take a look at shFlags which is a portable shell library (meaning: sh, bash, dash, ksh, zsh on Linux, Solaris, etc.).

It makes adding new flags as simple as adding one line to your script, and it provides an auto generated usage function.

Here is a simple Hello, world! using shFlag:

#!/bin/sh

# source shflags from current directory
. ./shflags

# define a 'name' command-line string flag
DEFINE_string 'name' 'world' 'name to say hello to' 'n'

# parse the command-line
FLAGS "$@" || exit 1
eval set -- "${FLAGS_ARGV}"

# say hello
echo "Hello, ${FLAGS_name}!"

For OSes that have the enhanced getopt that supports long options (e.g. Linux), you can do:

$ ./hello_world.sh --name Kate
Hello, Kate!

For the rest, you must use the short option:

$ ./hello_world.sh -n Kate
Hello, Kate!

Adding a new flag is as simple as adding a new DEFINE_ call.