add convenience shell script for lists

2 files changed, 767 insertions, 0 deletions

diff --git a/getopts_long.sh b/getopts_long.sh
new file mode 100644
index 0000000..ce2f7f0
--- /dev/null
+++ b/getopts_long.sh
@@ -0,0 +1,701 @@
+#! /bin/echo Usage:.
+# 
+# getopts_long -- POSIX shell getopts with GNU-style long option support
+#
+# Copyright 2005-2009 Stephane Chazelas <stephane_chazelas@yahoo.fr>
+# 
+# Permission to use, copy, modify, distribute, and sell this software and
+# its documentation for any purpose is hereby granted without fee, provided
+# that the above copyright notice appear in all copies and that both that
+# copyright notice and this permission notice appear in supporting
+# documentation.  No representations are made about the suitability of this
+# software for any purpose.  It is provided "as is" without express or
+# implied warranty.
+
+# History:
+# 2005 ?? - 1.0
+#   first version
+# 2009-08-12 - 1.1
+#   thanks to ujqm8360@netwtc.net for helping fix a few bugs:
+#     - -ab x where -b accepts arguments wasn't handled properly. Also,
+#       $OPTLIND wasn't set properly (at least not the same way as most
+#       getopts implementation do).
+#     - The handling of ambiguous long options was incorrect.
+
+getopts_long() {
+  # args: shortopts, var, [name, type]*, "", "$@"
+  #
+  # getopts_long parses command line arguments. It works like the
+  # getopts shell built-in command except that it also recognises long
+  # options a la GNU.
+  #
+  # You must provide getopts_long with the list of supported single
+  # letter options in the same format as getopts', followed by the
+  # variable name you want getopts_long to return the current processed
+  # option in, followed by the list of long option names (without the
+  # leading "--") and types (0 or no_argument, 1 or required_argument,
+  # 2 or optional_argument). The end of the long option specification
+  # is indicated by an empty argument. Then follows the list of
+  # arguments to be parsed.
+  #
+  # The $OPTLIND variable must be set to 1 before the first call of the
+  # getopts_long function to process a given list of arguments.
+  #
+  # getopts_long returns the value of the current option in the variable
+  # whose name is provided as its second argument (be careful to avoid
+  # variables that have a special signification to getopts_long or the
+  # shell or any other tool you may call from your script). If the
+  # current option is a single letter option, then it is returned
+  # without the leading "-". If it's a long option (possibly
+  # abbreviated), then the full name of the option (without the leading
+  # "--") is returned. If the option has an argument, then it is stored
+  # in the $OPTLARG variable. If the current option is not recognised,
+  # or if it is provided with an argument while it is not expecting one
+  # (as in --opt=value) or if it is not provided with an argument while
+  # it is expecting one, or if the option is so abbreviated that it is
+  # impossible to identify the option uniquely, then:
+  #   - if the short option specifications begin with ":", getopts_long
+  #     returns ":" in the output variable and $OPTLARG contains the
+  #     faulty option name (in full except in the case of the ambiguous
+  #     or bad option) and $OPTLERR contains the error message.
+  #   - if not, then getopts_long behaves the same as above except that
+  #     it returns "?" instead of ":", leaves $OPTLARG unset and
+  #     displays the error message on stderr.
+  #
+  # The exit status of getopts_long is 0 unless the end of options is
+  # reached or an error is encountered in the syntax of the getopts_long
+  # call.
+  #
+  # After getopts_long has finished processing the options, $OPTLIND
+  # contains the index of the first non-option argument or $# + 1 if
+  # there's no non-option argument.
+  #
+  # The "=" character is not allowed in a long option name. Any other
+  # character is. "-" and ":" are not allowed as short option names. Any
+  # other character is. If a short option appears more than once in the
+  # specification, the one with the greatest number of ":"s following it
+  # is retained. If a long option name is provided more than once, only
+  # the first one is taken into account. Note that if you have both a -a
+  # and --a option, there's no way to differentiate them. Beside the
+  # $OPTLIND, $OPTLARG, and $OPTLERR, getopts_long uses the $OPTLPENDING
+  # variable to hold the remaining options to be processed for arguments
+  # with several one-letter options. That variable shouldn't be used
+  # anywhere else in your script. Those 4 variables are the only ones
+  # getopts_long may modify.
+  #
+  # Dependency: only POSIX utilities are called by that function. They
+  # are "set", "unset", "shift", "break", "return", "eval", "command",
+  # ":", "printf" and "[". Those are generally built in the POSIX
+  # shells. Only "printf" has been known not to be in some old versions
+  # of bash, zsh or ash based shells.
+  #
+  # Differences with the POSIX getopts:
+  #  - if an error is detected during the parsing of command line
+  #    arguments, the error message is stored in the $OPTLERR variable
+  #    and if the first character of optstring is ':', ':' is returned in
+  #    any case.
+  #  - in the single-letter option specification, if a letter is
+  #    followed by 2 colons ("::"), then the option can have an optional
+  #    argument as in GNU getopt(3). In that case, the argument must
+  #    directly follow the option as in -oarg (not -o arg).
+  #  - there must be an empty argument to mark the end of the option
+  #    specification.
+  #  - long options starting with "--" are supported.
+  #
+  # Differences with GNU getopt_long(3):
+  #  - getopts_long doesn't allow options to be interspersed with other
+  #    arguments (as if POSIXLY_CORRECT was set for GNU getopt_long(3))
+  #  - there's no linkage of any sort between the short and long
+  #    options. The caller is responsible of that (see example below).
+  #
+  # Compatibility:
+  #  getopts_long code is (hopefully) POSIX.2/SUSv3 compliant. It won't
+  #  work with the Bourne/SystemV shell. Use /usr/xpg4/bin/sh or ksh or
+  #  bash on Solaris.
+  #  It has been tested successfully with:
+  #    - bash 3.0 (patch level 16) on Cygwin
+  #    - zsh 4.2.4 on Solaris 2.7
+  #    - /usr/xpg4/bin/sh (same as /usr/bin/ksh) (ksh88i) on Solaris 2.7
+  #    - /usr/dt/bin/dtksh (ksh93d) on Solaris 2.7
+  #    - /usr/bin/ksh (pdksh 5.2.14) on Linux
+  #    - zsh 3.0.6 on Solaris 2.8
+  #    - bash 2.0.3 on Solaris 2.8
+  #    - dash 0.5.2 on Linux
+  #    - bash 2.05b (patch level 0) on Linux
+  #    - ksh93p and ksh93q on Linux (ksh93t+ crashes)
+  #
+  #  It is known to fail with those non-POSIX compliant shells:
+  #    - /bin/sh on Solaris
+  #    - /usr/bin/sh on Cygwin
+  #    - bash 1.x
+  #
+  # Bugs:
+  #  please report them to <stephane_chazelas@yahoo.fr>
+  #
+  # Example:
+  #
+  # verbose=false opt_bar=false bar=default_bar foo=default_foo
+  # opt_s=false opt_long=false
+  # OPTLIND=1
+  # while getopts_long :sf:b::vh opt \
+  #   long 0 \
+  #   foo required_argument \
+  #   bar 2 \
+  #   verbose no_argument \
+  #   help 0 "" "$@"
+  # do
+  #   case "$opt" in
+  #     s) opt_s=true;;
+  #     long) opt_long=true;;
+  #     v|verbose) verbose=true;;
+  #     h|help) usage; exit 0;;
+  #     f|foo) foo=$OPTLARG;;
+  #     b|bar) bar=${OPTLARG-$bar};;
+  #     :) printf >&2 '%s: %s\n' "${0##*/}" "$OPTLERR"
+  #        usage
+  #        exit 1;;
+  #   esac
+  # done
+  # shift "$(($OPTLIND - 1))"
+  # # process the remaining arguments
+
+  [ -n "${ZSH_VERSION+z}" ] && emulate -L sh
+
+  unset OPTLERR OPTLARG || :
+
+  case "$OPTLIND" in
+    "" | 0 | *[!0-9]*)
+      # First time in the loop. Initialise the parameters.
+      OPTLIND=1
+      OPTLPENDING=
+      ;;
+  esac
+
+  if [ "$#" -lt 2 ]; then
+    printf >&2 'getopts_long: not enough arguments\n'
+    return 1
+  fi
+
+  # validate variable name. Need to fix locale for character ranges.
+  LC_ALL=C command eval '
+    case "$2" in
+      *[!a-zA-Z_0-9]*|""|[0-9]*)
+        printf >&2 "getopts_long: invalid variable name: \`%s'\''\n" "$2"
+        return 1
+        ;;
+    esac'
+
+  # validate short option specification
+  case "$1" in
+    ::*|*:::*|*-*)
+      printf >&2 "getopts_long: invalid option specification: \`%s'\n" "$1"
+      return 1
+      ;;
+  esac
+
+  # validate long option specifications
+
+  # POSIX shells only have $1, $2... as local variables, hence the
+  # extensive use of "set" in that function.
+
+  set 4 "$@"
+  while :; do
+    if
+      [ "$1" -gt "$#" ] || {
+        eval 'set -- "${'"$1"'}" "$@"'
+        [ -n "$1" ] || break
+        [ "$(($2 + 2))" -gt "$#" ]
+      }
+    then
+      printf >&2 "getopts_long: long option specifications must end in an empty argument\n"
+      return 1
+    fi
+    eval 'set -- "${'"$(($2 + 2))"'}" "$@"'
+    # $1 = type, $2 = name, $3 = $@
+    case "$2" in
+      *=*)
+        printf >&2 "getopts_long: invalid long option name: \`%s'\n" "$2"
+        return 1
+        ;;
+    esac
+    case "$1" in
+      0 | no_argument) ;;
+      1 | required_argument) ;;
+      2 | optional_argument) ;;
+      *)
+        printf >&2 "getopts_long: invalid long option type: \`%s'\n" "$1"
+        return 1
+        ;;
+    esac
+    eval "shift 3; set $(($3 + 2))"' "$@"'
+  done
+  shift
+
+  eval "shift; set $(($1 + $OPTLIND))"' "$@"'
+
+  # unless there are pending short options to be processed (in
+  # $OPTLPENDING), the current option is now in ${$1}
+
+  if [ -z "$OPTLPENDING" ]; then
+    [ "$1" -le "$#" ] || return 1
+    eval 'set -- "${'"$1"'}" "$@"'
+
+    case "$1" in
+      --)
+        OPTLIND=$(($OPTLIND + 1))
+        return 1
+        ;;
+      --*)
+        OPTLIND=$(($OPTLIND + 1))
+        ;;
+      -?*)
+        OPTLPENDING="${1#-}"
+        shift
+        ;;
+      *)
+        return 1
+        ;;
+    esac
+  fi
+
+  if [ -n "$OPTLPENDING" ]; then
+    # WA for zsh and bash 2.03 bugs:
+    OPTLARG=${OPTLPENDING%"${OPTLPENDING#?}"}
+    set -- "$OPTLARG" "$@"
+    OPTLPENDING="${OPTLPENDING#?}"
+    unset OPTLARG
+
+    # $1 = current option = ${$2+1}, $3 = $@
+
+    [ -n "$OPTLPENDING" ] ||
+      OPTLIND=$(($OPTLIND + 1))
+
+    case "$1" in
+      [-:])
+        OPTLERR="bad option: \`-$1'"
+        case "$3" in
+          :*)
+            eval "$4=:"
+            OPTLARG="$1"
+            ;;
+          *)
+            printf >&2 '%s\n' "$OPTLERR"
+            eval "$4='?'"
+            ;;
+        esac
+        ;;
+
+      *)
+        case "$3" in
+          *"$1"::*) # optional argument
+            eval "$4=\"\$1\""
+            if [ -n "$OPTLPENDING" ]; then
+              # take the argument from $OPTLPENDING if any
+              OPTLARG="$OPTLPENDING"
+              OPTLPENDING=
+              OPTLIND=$(($OPTLIND + 1))
+            fi
+            ;;
+
+          *"$1":*) # required argument
+            if [ -n "$OPTLPENDING" ]; then
+              # take the argument from $OPTLPENDING if any
+              OPTLARG="$OPTLPENDING"
+              eval "$4=\"\$1\""
+              OPTLPENDING=
+              OPTLIND=$(($OPTLIND + 1))
+            else
+              # take the argument from the next argument
+              if [ "$(($2 + 2))" -gt "$#" ]; then
+                OPTLERR="option \`-$1' requires an argument"
+                case "$3" in
+                  :*)
+                    eval "$4=:"
+                    OPTLARG="$1"
+                    ;;
+                  *)
+                    printf >&2 '%s\n' "$OPTLERR"
+                    eval "$4='?'"
+                    ;;
+                esac
+              else
+                OPTLIND=$(($OPTLIND + 1))
+                eval "OPTLARG=\"\${$(($2 + 2))}\""
+                eval "$4=\"\$1\""
+              fi
+            fi
+            ;;
+
+          *"$1"*) # no argument
+            eval "$4=\"\$1\""
+            ;;
+          *)
+            OPTLERR="bad option: \`-$1'"
+            case "$3" in
+              :*)
+                eval "$4=:"
+                OPTLARG="$1"
+                ;;
+              *)
+                printf >&2 '%s\n' "$OPTLERR"
+                eval "$4='?'"
+                ;;
+            esac
+            ;;
+        esac
+        ;;
+    esac
+  else # long option
+
+    # remove the leading "--"
+    OPTLPENDING="$1"
+    shift
+    set 6 "${OPTLPENDING#--}" "$@"
+    OPTLPENDING=
+
+    while
+      eval 'set -- "${'"$1"'}" "$@"'
+      [ -n "$1" ]
+    do
+      # $1 = option name = ${$2+1}, $3 => given option = ${$4+3}, $5 = $@
+
+      case "${3%%=*}" in
+        "$1")
+          OPTLPENDING=EXACT
+          break;;
+      esac
+
+      # try to see if the current option can be seen as an abbreviation.
+      case "$1" in
+        "${3%%=*}"*)
+          if [ -n "$OPTLPENDING" ]; then
+            [ "$OPTLPENDING" = AMBIGUOUS ] || eval '[ "${'"$(($OPTLPENDING + 1))"'}" = "$1" ]' ||
+              OPTLPENDING=AMBIGUOUS
+              # there was another different option matching the current
+              # option. The eval thing is in case one option is provided
+              # twice in the specifications which is OK as per the
+              # documentation above
+          else
+            OPTLPENDING="$2"
+          fi
+          ;;
+      esac
+      eval "shift 2; set $(($2 + 2)) "'"$@"'
+    done
+
+    case "$OPTLPENDING" in
+      AMBIGUOUS)
+        OPTLERR="option \`--${3%%=*}' is ambiguous"
+        case "$5" in
+          :*)
+            eval "$6=:"
+            OPTLARG="${3%%=*}"
+            ;;
+          *)
+            printf >&2 '%s\n' "$OPTLERR"
+            eval "$6='?'"
+            ;;
+        esac
+        OPTLPENDING=
+        return 0
+        ;;
+      EXACT)
+        eval 'set "${'"$(($2 + 2))"'}" "$@"'
+        ;;
+      "")
+        OPTLERR="bad option: \`--${3%%=*}'"
+        case "$5" in
+          :*)
+            eval "$6=:"
+            OPTLARG="${3%%=*}"
+            ;;
+          *)
+            printf >&2 '%s\n' "$OPTLERR"
+            eval "$6='?'"
+            ;;
+        esac
+        OPTLPENDING=
+        return 0
+        ;;
+      *)
+        # we've got an abbreviated long option.
+        shift
+        eval 'set "${'"$(($OPTLPENDING + 1))"'}" "${'"$OPTLPENDING"'}" "$@"'
+        ;;
+    esac
+
+    OPTLPENDING=
+
+    # $1 = option type, $2 = option name, $3 unused,
+    # $4 = given option = ${$5+4}, $6 = $@
+
+    case "$4" in
+      *=*)
+        case "$1" in
+          1 | required_argument | 2 | optional_argument)
+            eval "$7=\"\$2\""
+            OPTLARG="${4#*=}"
+            ;;
+          *)
+            OPTLERR="option \`--$2' doesn't allow an argument"
+            case "$6" in
+              :*)
+                eval "$7=:"
+                OPTLARG="$2"
+                ;;
+              *)
+                printf >&2 '%s\n' "$OPTLERR"
+                eval "$7='?'"
+                ;;
+            esac
+            ;;
+        esac
+        ;;
+
+      *)
+        case "$1" in
+          1 | required_argument)
+            if [ "$(($5 + 5))" -gt "$#" ]; then
+              OPTLERR="option \`--$2' requires an argument"
+              case "$6" in
+                :*)
+                  eval "$7=:"
+                  OPTLARG="$2"
+                  ;;
+                *)
+                  printf >&2 '%s\n' "$OPTLERR"
+                  eval "$7='?'"
+                  ;;
+              esac
+            else
+              OPTLIND=$(($OPTLIND + 1))
+              eval "OPTLARG=\"\${$(($5 + 5))}\""
+              eval "$7=\"\$2\""
+            fi
+            ;;
+          *)
+            # optional argument (but obviously not provided) or no
+            # argument
+            eval "$7=\"\$2\""
+            ;;
+        esac
+        ;;
+    esac
+  fi
+  return 0
+}
+
+# testing code
+if [ -n "$test_getopts_long" ]; then
+test_getopts_long() {
+  expected="$1" had=
+  shift
+  OPTLIND=1
+
+  while err="$(set +x;getopts_long "$@" 2>&1 > /dev/null)"
+    getopts_long "$@" 2> /dev/null; do
+    eval "opt=\"\$$2\""
+    had="$had|$opt@${OPTLARG-unset}@${OPTLIND-unset}@${OPTLERR-unset}@$err"
+  done
+  had="$had|${OPTLIND-unset}|$err"
+
+  if [ "$had" = "$expected" ]; then
+    echo PASS
+  else
+    echo FAIL
+    printf 'Expected: %s\n     Got: %s\n' "$expected" "$had"
+  fi
+}
+while IFS= read -r c && IFS= read -r e; do
+  printf '+ %-72s ' "$c"
+  #set -x
+  eval "test_getopts_long \"\$e\" $c"
+done << \EOF
+: a
+|1|getopts_long: long option specifications must end in an empty argument
+:a opt "" -a
+|a@unset@2@unset@|2|
+:a opt "" -a b
+|a@unset@2@unset@|2|
+:a opt "" -a -a
+|a@unset@2@unset@|a@unset@3@unset@|3|
+:a opt "" -ab
+|a@unset@1@unset@|:@b@2@bad option: `-b'@|2|
+:a: opt "" -ab
+|a@b@2@unset@|2|
+:a: opt "" -a b
+|a@b@3@unset@|3|
+:a: opt "" -a -a
+|a@-a@3@unset@|3|
+:a: opt "" -a
+|:@a@2@option `-a' requires an argument@|2|
+:a:: opt "" -a
+|a@unset@2@unset@|2|
+:a:: opt "" -ab
+|a@b@2@unset@|2|
+:a:: opt "" -a b
+|a@unset@2@unset@|2|
+:ab: opt "" -ab c
+|a@unset@1@unset@|b@c@3@unset@|3|
+:a:: opt "" -a -a
+|a@unset@2@unset@|a@unset@3@unset@|3|
+:a:: opt "" -:a:
+|:@:@1@bad option: `-:'@|a@:@2@unset@|2|
+:= opt ""
+|1|
+:: opt ""
+|1|getopts_long: invalid option specification: `::'
+: opt ""
+|1|
+:a:a opt "" -a
+|:@a@2@option `-a' requires an argument@|2|
+:a::a opt "" -a
+|a@unset@2@unset@|2|
+:ab:c:: opt "" -abc -cba -bac
+|a@unset@1@unset@|b@c@2@unset@|c@ba@3@unset@|b@ac@4@unset@|4|
+: opt abc 0 "" --abc
+|abc@unset@2@unset@|2|
+: opt abc no_argument "" --abc
+|abc@unset@2@unset@|2|
+: opt abc no_argument "" --abc=foo
+|:@abc@2@option `--abc' doesn't allow an argument@|2|
+: opt abc no_argument "" --abc foo
+|abc@unset@2@unset@|2|
+: opt abc 1 "" --abc=foo
+|abc@foo@2@unset@|2|
+: opt abc required_argument "" --abc foo
+|abc@foo@3@unset@|3|
+: opt abc required_argument "" --abc=
+|abc@@2@unset@|2|
+: opt abc required_argument "" --abc
+|:@abc@2@option `--abc' requires an argument@|2|
+: opt abc 2 "" --abc
+|abc@unset@2@unset@|2|
+: opt abc optional_argument "" --abc=
+|abc@@2@unset@|2|
+: opt abc optional_argument "" --abc=foo
+|abc@foo@2@unset@|2|
+: opt abc optional_argument "" --abc --abc
+|abc@unset@2@unset@|abc@unset@3@unset@|3|
+: opt abc 0 abcd 0 "" --abc
+|abc@unset@2@unset@|2|
+: opt abc 0 abd 0 "" --ab
+|:@ab@2@option `--ab' is ambiguous@|2|
+: opt abc 0 abcd 0 "" --ab
+|:@ab@2@option `--ab' is ambiguous@|2|
+: opt abc 0 abc 1 "" --ab
+|abc@unset@2@unset@|2|
+: opt abc 0 abc 1 "" --abc
+|abc@unset@2@unset@|2|
+: opt abc 0 abc 1 "" --ab
+|abc@unset@2@unset@|2|
+: opt abc 0 acd 0 "" --ab
+|abc@unset@2@unset@|2|
+:abc:d:e::f:: opt ab 0 ac 1 bc 2 cd 1 cde 2 "" -abcdef -a -f -c --a --a= --b=foo -fg
+|a@unset@1@unset@|b@unset@1@unset@|c@def@2@unset@|a@unset@3@unset@|f@unset@4@unset@|c@--a@6@unset@|:@a@7@option `--a' is ambiguous@|bc@foo@8@unset@|f@g@9@unset@|9|
+a opt "" -a
+|a@unset@2@unset@|2|
+a opt "" -a b
+|a@unset@2@unset@|2|
+a opt "" -a -a
+|a@unset@2@unset@|a@unset@3@unset@|3|
+a opt "" -ab
+|a@unset@1@unset@|?@unset@2@bad option: `-b'@bad option: `-b'|2|
+a: opt "" -ab
+|a@b@2@unset@|2|
+a: opt "" -a b
+|a@b@3@unset@|3|
+a: opt "" -a -a
+|a@-a@3@unset@|3|
+a: opt "" -a
+|?@unset@2@option `-a' requires an argument@option `-a' requires an argument|2|
+a:: opt "" -a
+|a@unset@2@unset@|2|
+a:: opt "" -ab
+|a@b@2@unset@|2|
+a:: opt "" -a b
+|a@unset@2@unset@|2|
+a:: opt "" -a -a
+|a@unset@2@unset@|a@unset@3@unset@|3|
+a:: opt "" -:a:
+|?@unset@1@bad option: `-:'@bad option: `-:'|a@:@2@unset@|2|
+= opt ""
+|1|
+: opt ""
+|1|
+'' opt ""
+|1|
+a:a opt "" -a
+|?@unset@2@option `-a' requires an argument@option `-a' requires an argument|2|
+a::a opt "" -a
+|a@unset@2@unset@|2|
+ab:c:: opt "" -abc -cba -bac
+|a@unset@1@unset@|b@c@2@unset@|c@ba@3@unset@|b@ac@4@unset@|4|
+'' opt abc 0 "" --abc
+|abc@unset@2@unset@|2|
+'' opt abc no_argument "" --abc
+|abc@unset@2@unset@|2|
+'' opt abc no_argument "" --abc=foo
+|?@unset@2@option `--abc' doesn't allow an argument@option `--abc' doesn't allow an argument|2|
+'' opt abc no_argument "" --abc foo
+|abc@unset@2@unset@|2|
+'' opt abc 1 "" --abc=foo
+|abc@foo@2@unset@|2|
+'' opt abc required_argument "" --abc foo
+|abc@foo@3@unset@|3|
+'' opt abc required_argument "" --abc=
+|abc@@2@unset@|2|
+'' opt abc required_argument "" --abc
+|?@unset@2@option `--abc' requires an argument@option `--abc' requires an argument|2|
+'' opt abc 2 "" --abc
+|abc@unset@2@unset@|2|
+'' opt abc optional_argument "" --abc=
+|abc@@2@unset@|2|
+'' opt abc optional_argument "" --abc=foo
+|abc@foo@2@unset@|2|
+'' opt abc optional_argument "" --abc --abc
+|abc@unset@2@unset@|abc@unset@3@unset@|3|
+'' opt abc 0 abcd 0 "" --abc
+|abc@unset@2@unset@|2|
+'' opt abc 0 abd 0 "" --ab
+|?@unset@2@option `--ab' is ambiguous@option `--ab' is ambiguous|2|
+'' opt abc 0 abcd 0 "" --ab
+|?@unset@2@option `--ab' is ambiguous@option `--ab' is ambiguous|2|
+'' opt abc 0 abc 1 "" --ab
+|abc@unset@2@unset@|2|
+'' opt abc 0 abc 1 "" --abc
+|abc@unset@2@unset@|2|
+'' opt abc 0 abc 1 "" --ab
+|abc@unset@2@unset@|2|
+'' opt abc 0 acd 0 "" --ab
+|abc@unset@2@unset@|2|
+abc:d:e::f:: opt ab 0 ac 1 bc 2 cd 1 cde 2 "" -abcdef -a -f -c --a --a= --b=foo -fg
+|a@unset@1@unset@|b@unset@1@unset@|c@def@2@unset@|a@unset@3@unset@|f@unset@4@unset@|c@--a@6@unset@|?@unset@7@option `--a' is ambiguous@option `--a' is ambiguous|bc@foo@8@unset@|f@g@9@unset@|9|
+: '' '' a
+|1|getopts_long: invalid variable name: `'
+: 1a ''
+|1|getopts_long: invalid variable name: `1a'
+- a
+|1|getopts_long: invalid option specification: `-'
+:a::a:abcd o ab 1 abc 1 abd 1 abe 1 abc 2 '' -aa --ab 1 --abc
+|a@a@2@unset@|ab@1@4@unset@|:@abc@5@option `--abc' requires an argument@|5|
+:
+|1|getopts_long: not enough arguments
+'\[$' o -- 0 ' ' 1 '#' required_argument '' '-\\\[$' --\ =a --\#=\$\$
+|\@unset@1@unset@|\@unset@1@unset@|\@unset@1@unset@|[@unset@1@unset@|$@unset@2@unset@| @a@3@unset@|#@$$@4@unset@|4|
+: o a 1 b 2 c
+|1|getopts_long: long option specifications must end in an empty argument
+: o a 1 b 2
+|1|getopts_long: long option specifications must end in an empty argument
+: o a 1 b 2 c 3 '' --c
+|1|getopts_long: invalid long option type: `3'
+":  " o "  " 1 '' "-  " "--  =1"
+| @unset@1@unset@| @unset@2@unset@|  @1@3@unset@|3|
+: o a 1 '' --c
+|:@c@2@bad option: `--c'@|2|
+: o a 1 '' --c=foo
+|:@c@2@bad option: `--c'@|2|
+: o ab 1 ac 1 ad 1 a 1 '' --a=1
+|a@1@2@unset@|2|
+EOF
+fi
diff --git a/lists.sh b/lists.sh
new file mode 100755
index 0000000..c07870a
--- /dev/null
+++ b/lists.sh
@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+
+shopt -s extglob nullglob
+
+. ./getopts_long.sh
+
+find_lists() {
+    LISTS=()
+    while read -r -d $'\0'; do
+        local list=$(realpath --relative-to=. "$REPLY")
+        LISTS+=("$list")
+    done < <(find lists -maxdepth 1 -mindepth 1 -type d -not -name '.*' -print0 | sort -z)
+}
+
+find_posts() {
+    local list="$1"
+    shift 1
+
+    POSTS=()
+    for p in "$list"/!(*[!0-9]*); do
+        POSTS+=( "$p" )
+    done
+}
+
+print_lists() {
+    find_lists
+    for x in "${LISTS[@]}"; do
+        printf "%s: %s\n" "$x" "$(<$x/title)"
+    done
+}
+
+print_posts() {
+    find_posts "$1"
+    for p in "${POSTS[@]}"; do
+        local post=$(readlink "$p")
+        printf "%s: %s\n" "${p##*/}" "${post##*/}"
+    done
+}
+
+add_list() {
+    local list="$1"
+    mkdir lists/"$list"
+    shift 1
+    echo "$@" >lists/"$list"/title
+}
+
+while getopts_long ":la:" opt \
+                   posts required_argument \
+                   "" "$@"
+do
+    case $opt in
+        l)
+            print_lists
+            exit 0;;
+        a)
+            shift "$(($OPTLIND - 1))"
+            add_list "$OPTLARG" "$@"
+            exit 0;;
+        posts)
+            print_posts "$OPTLARG"
+            ;;
+        :)
+            printf >&2 '%s: %s\n' "${0##*/}" "$OPTLERR"
+            exit 1;;
+    esac
+done