2020-07-01 解析bash shell脚本命令行参数

#!/bin/bash

# function
function blastn() {
    blastn -db ... -query .... -out ... -outfmt ...
}

function description() {
    echo "Name:"
    echo "bashDemo written by Y.P.CHEN:email@.com, 2020-07-01, chengdu"
    echo "Synopsis:"
    echo "show how to parse command-line arguments in bash shell"
    echo "Usage:"   
    echo "bashDemo [option] arg ..."
    echo "Example command:"
    echo "...."
}

function print_help() {
    grep '^##' $0 | sed 's/##//'
    exit 1 
}

# print help and exit
if [[ $# -eq 0 ]]; then
    print_help
fi

if [[ $1 == "-h" || $1 == "--help" || $1 == "-help" ]]; then
    print_help
fi

# check input
if [[ $# -ne 6 && $# -ne 14 ]]; then
    echo '**Error invalid parameters group'
    echo '----------------------------------------------------'
    print_help
fi

# parse command-line arguments
while getopts i:o:t: OPT; do
    case $OPT in
        i)
          input=$OPTARG
          ;;
        o)
          output=$OPTARG
          ;;
        t)
          threads=$OPTARG
          ;;
        ?)
          echo "unkonw argument"
          exit 1
        ;;
    esac
done
shift $((OPTIND - 1))

# main



# call function blastn
blastn

# check variable
if [[ $input && $output && $threads ]]; then
    ...
fi

# if the variables do not exists.
if [[  !$input & ]]; then
    ...
fi