Merge gi_extension project into git extras as git-ignore-io

* gi_extension(https://github.com/Lee-W/gi_extension)

bin/git-ignore-io

@@ -0,0 +1,119 @@
+#/bin/sh
+
+gitignore_io_url="https://www.gitignore.io/api/"
+
+default_path="$HOME/.gi_list"
+gi_list=`cat $default_path | tr "," "\n"`
+
+update_gi_list() {
+    curl -L -s  "${gitignore_io_url}/list" > ~/.gi_list
+}
+
+print_in_alphabetical_order() {
+    for i in {a..z};
+    do
+        echo "$gi_list" | grep "^$i" | tr "\n" " "
+        echo
+    done
+}
+
+print_in_table_format() {
+    table_width=5
+    coulumn_width=25
+
+    counter=0
+    for item in $gi_list; do
+        printf "%-${coulumn_width}s" $item
+        counter=$(($counter+1))
+        if [[ $(($counter%$table_width)) -eq 0 ]]; then
+            echo
+        fi
+    done
+    echo
+}
+
+print_last_modified_time() {
+    local gi_list_date=`stat -f "%t%Sm" $default_path`
+    echo "Last update time: $gi_list_date"
+}
+
+gi() {
+    curl -L -s $gitignore_io_url/$1
+}
+
+gi_export() {
+    gi $1 > .gitignore
+}
+
+gi_append() {
+    gi $1 >> .gitignore
+}
+
+show_usage() {
+    echo "usage: gi <types>"
+    echo "          [-a| -e] <types>"
+    echo "          [-u| -t| -l| -L]"
+    echo "          [-h]"
+}
+
+print_help_message() {
+    echo "-a [types]      apeend new .gitignore content to .gitignore under the current directory"
+    echo "-e [types]      export new .gitignore to the current directory (The old one will be replaced.)"
+    echo "-L              print ~/.gi_list in alphabetical order"
+    echo "-l              print ~/.gi_list in table format"
+    echo "-u              update ~/.gi_list"
+    echo "-t              show the last modified time of ~/.gi_list"
+    echo "-h              show help"
+}
+
+
+update_gi_list &
+if [[ $# -eq 0 ]]; then
+    show_usage
+else
+    case $1 in
+        -a|-e)
+            opt=$1
+            shift
+            if [[ $# -eq 0 ]]; then
+                show_usage
+                exit
+            fi
+
+            gi_to_curl=`echo $@ | tr " " ","`
+            case $opt in
+            -a)
+                gi_append $gi_to_curl
+                ;;
+            -e)
+                gi_export $gi_to_curl
+                ;;
+            esac
+
+            exit
+            ;;
+        -t)
+            print_last_modified_time
+            ;;
+        -u)
+            update_gi_list
+            ;;
+        -L)
+            print_in_alphabetical_order
+            ;;
+        -l)
+            print_in_table_format
+            ;;
+        -h)
+            print_help_message
+            ;;
+        -*)
+            echo No Such option
+            show_usage
+            ;;
+        *)
+            gi_to_curl=`echo $@ | tr " " ","`
+            gi $gi_to_curl
+            ;;
+    esac
+fi