include/opt: Add flag to define required arguments

The opt module currently does not provide a means to define required
arguments, making it hard for the callee to determine if an argument
was provided on the commandline, or if the default value was returned
by opt_get().
This commit adds a flag to specify if an argument must be provided on
the commandline. Further, since multiple flags can now be passed to
opt_add_arg(), the flag format is changed: now, a string containing
all flags as characters must be passed. The implementation understands
the following flags:

 r - Argument is required
 v - Argument has a value (e.g. is followed by a second argument)

For example, to declare a required argument with a value, one would
pass the flags "rv".

diff --git a/include/opt.sh b/include/opt.sh
index d04e3e88064c3fd7b6e5da4c2d37f0fc7636866b..1a612ed68530a60a59583aafc472e56e2b99ca9b 100644 (file)
--- a/include/opt.sh
+++ b/include/opt.sh
@@ -5,24 +5,28 @@ __init() {
                return 1
        fi
 
+       declare -xgir __opt_flag_required=1
+       declare -xgir __opt_flag_has_value=2
+
        declare -Axg __opt_short=()
        declare -Axg __opt_long=()
        declare -Axg __opt_desc=()
        declare -Axg __opt_flags=()
        declare -Axg __opt_value=()
+       declare -Axg __opt_default=()
        declare -Axg __opt_action=()
        declare -Axg __opt_map=()
        declare -xgi __opt_num=0
        declare -xgi __opt_longest=0
 
-       opt_add_arg "h" "help" "no" 0 \
+       opt_add_arg "h" "help" "" 0 \
                    "Print this text" \
                    opt_print_help
 
-       opt_add_arg "v" "verbose" "no" 0 \
+       opt_add_arg "v" "verbose" "" 0 \
                    "Be more verbose" \
                    log_increase_verbosity
-       opt_add_arg "w" "shush" "no" 0 \
+       opt_add_arg "w" "shush" "" 0 \
                    "Be less verbose" \
                    log_decrease_verbosity
 
@@ -38,6 +42,9 @@ opt_add_arg() {
        local action
 
        local optlen
+       local num_flags
+       local bflags
+       local i
 
        short="$1"
        long="$2"
@@ -51,13 +58,32 @@ opt_add_arg() {
                return 1
        fi
 
+       num_flags="${#flags}"
+       bflags=0
+
+       for (( i = 0; i < num_flags; i++ )); do
+               case "${flags:$i:1}" in
+                       "r")
+                               ((bflags |= __opt_flag_required))
+                               ;;
+
+                       "v")
+                               ((bflags |= __opt_flag_has_value))
+                               ;;
+
+                       *)
+                               return 1
+                               ;;
+               esac
+       done
+
        optlen="${#long}"
 
        __opt_short["$long"]="$short"
        __opt_long["$short"]="$long"
-       __opt_flags["$long"]="$flags"
+       __opt_flags["$long"]="$bflags"
        __opt_desc["$long"]="$desc"
-       __opt_value["$long"]="$default"
+       __opt_default["$long"]="$default"
        __opt_action["$long"]="$action"
 
        __opt_map["-$short"]="$long"
@@ -105,11 +131,14 @@ opt_print_help() {
 }
 
 opt_parse() {
-       local opt
+       local optname
+       local err
        local i
 
        declare -argx __opt_argv=("$@")
 
+       err=0
+
        for (( i = 1; i <= $#; i++ )); do
                local param
                local long
@@ -128,7 +157,7 @@ opt_parse() {
                flags="${__opt_flags[$long]}"
                action="${__opt_action[$long]}"
 
-               if [[ "$flags" == "yes" ]]; then
+               if (( flags & __opt_flag_has_value )); then
                        ((i++))
 
                        if (( i > $# )); then
@@ -144,7 +173,7 @@ opt_parse() {
 
                __opt_value["$long"]="$value"
 
-               if ! [[ -z "$action" ]]; then
+               if [[ -n "$action" ]]; then
                        local err
 
                        "$action" "$long" "$value"
@@ -156,7 +185,22 @@ opt_parse() {
                fi
        done
 
-       return 0
+       for optname in "${__opt_long[@]}"; do
+               local flags
+
+               flags="${__opt_flags[$optname]}"
+
+               if ! (( flags & __opt_flag_required )); then
+                       continue
+               fi
+
+               if ! array_contains "$optname" "${!__opt_value[@]}"; then
+                       log_error "Missing required argument: $optname"
+                       err=1
+               fi
+       done
+
+       return "$err"
 }
 
 opt_get() {
@@ -164,11 +208,12 @@ opt_get() {
 
        long="$1"
 
-       if ! array_contains "$long" "${!__opt_value[@]}"; then
-               return 1
+       if array_contains "$long" "${!__opt_value[@]}"; then
+               echo "${__opt_value[$long]}"
+       else
+               echo "${__opt_default[$long]}"
        fi
 
-       echo "${__opt_value[$long]}"
        return 0
 }