コマンドライン引数を読み込むシェルスクリプトの実装

. /test.sh -f config.conf -v --prefix=

. /test.sh 10

#! /binif [ x$1 ! = x ]
then
  #... with argument logic
else
then
  #... No parameter logic
fi

if [ -n $1 ] #$1 is not empty

#test.sh
#! /binwhile getopts "a:bc" arg # A colon after an option means that the option takes an argument
do
        case $arg in
             a)
                echo "a's arg:$optarg" # arguments are in $optarg

             b)
                echo "b"

             c)
                echo "c"

             ?)  # When there is an unrecognized option arg for ?
            echo "unkonw argument"
        exit 1

        esac
done

. /test.sh -a arg -b -c

. /test.sh -a arg -bc

#! /bin# a small example program for using the new getopt(1) program.
# this program will only work with bash(1)
# an similar program using the tcsh(1) script language can be found
# as parse.tcsh
# example input and output (from the bash prompt):
# . /parse.bash -a par1 'another arg' --c-long 'wow!*\?' -cmore -b " very long "
# option a
# option c, no argument
# option c, argument `more'
# option b, argument ` very long '
# remaining arguments:
# --> `par1'
# --> `another arg'
# --> `wow!*\?'
# note that we use `"$@"' to let each command-line parameter expand to a
# The quotes around `$@' are essential!
# we need temp as the `eval set --' would nuke the return value of getopt.
# -o means short option, two colons means the option has an optional argument, the optional argument must be close to the option
#carg instead of --c arg
#--long indicates a long option
#"$@" explained above
# -n: message in case of error
# --: An example is better understood.
# We want to create a directory with the name "-f" What would you do?
# mkdir -f # doesn't work because -f will be parsed by mkdir as an option, then you can use
# mkdir -- -f so that -f is not used as an option.
temp=`getopt -o ab:c:: --long a-long,b-long:,c-long:: \
     -n 'example.bash' -- "$@"`
if [ $? ! = 0 ] ; then echo "terminating... " >&2 ; exit 1 ; fi
# note the quotes around `$temp': they are essential!
#set will rearrange the order of the arguments, i.e. change the values of $1,$2... The values of $n, which are rearranged in getopt
eval set -- "$temp"
# After the getopt process, the following process the specific options.
while true ; do
        case "$1" in
                -a|--a-long) echo "option a" ; shift ;;
                -b|--b-long) echo "option b, argument \`$2'" ; shift 2 ;;
                -c|--c-long)
                        # c has an optional argument. as we are in quoted mode,
                        # an empty parameter will be generated if its optional
                        # argument is not found.
                        case "$2" in
                                "") echo "option c, no argument"; shift 2 ;;
                                *) echo "option c, argument \`$2'" ; shift 2 ;;
                        esac ;;
                --) shift ; break ;;
                *) echo "internal error!" ; exit 1 ;;
        esac
done
echo "remaining arguments:"
for arg do
   echo '--> '"\`$arg'" ;
done

. /test -a -b arg arg1 -c

-a -b arg -c -- arg1