autocomplete : add my own funcs.

help/linux/bash/basic/autocomplete.md

@@ -68,3 +68,92 @@ chmod a+x admin.sh autocomplete.sh
 Source: https://askubuntu.com/a/483149/24155
 
 [source](https://unix.stackexchange.com/a/291867)
+
+# My own autocomplete functions.
+
+```bash
+# bash autocomplete.
+# usage: _foo () { _autocomplete "{foo,bar}" } ; complete -F _foo foo
+# there are also options like -o nospace. see man for more info.
+_autocomplete()
+{
+  local commands="$@"
+  local cur prev
+  
+  COMPREPLY=()
+
+  cur="${COMP_WORDS[COMP_CWORD]}"
+  prev="${COMP_WORDS[COMP_CWORD-1]}"
+  command="${COMP_WORDS[0]}"
+
+  COMPREPLY=( $(compgen -W "${commands}" -- ${cur}) )
+  return 0
+}
+
+# autocomplete only first argument.
+_autocomplete_first()
+{
+  local commands="$@"
+  local cur prev
+  
+  COMPREPLY=()
+
+  cur="${COMP_WORDS[COMP_CWORD]}"
+  prev="${COMP_WORDS[COMP_CWORD-1]}"
+  command="${COMP_WORDS[0]}"
+
+  if [[ "${prev}" = "${command}" ]]; then
+    COMPREPLY=( $(compgen -W "${commands}" -- ${cur}) )
+    return 0
+  fi
+}
+
+# autocomplete only first argument. the rest is ls output.
+_autocomplete_first_ls()
+{
+  local commands="$@"
+  local cur prev
+  
+  COMPREPLY=()
+
+  cur="${COMP_WORDS[COMP_CWORD]}"
+  prev="${COMP_WORDS[COMP_CWORD-1]}"
+  command="${COMP_WORDS[0]}"
+
+  if [[ "${prev}" = "${command}" ]]; then
+    COMPREPLY=( $(compgen -W "${commands}" -- ${cur}) )
+    return 0
+  else
+    COMPREPLY=( $(compgen -W "$(ls -a)" -- ${cur}) )
+    return 0
+  fi
+}
+
+# autocomplete nested program.
+_autocomplete_nested()
+{
+  local cur prev words cword split i
+  _init_completion -s || return
+
+  for ((i = 1; i <= cword; i++)); do
+    if [[ ${words[i]} != -* ]]; then
+      local PATH=$PATH:/sbin:/usr/sbin:/usr/local/sbin
+      local root_command=${words[i]}
+      _command_offset $i
+      return
+    fi
+  done
+}
+```
+
+sample usage:
+
+```bash
+# autocomplete.
+_tb_containers()
+{
+  _autocomplete "$(toolbox list -c | sed -e '1d' | awk '{ print $2 }')"
+}
+
+complete -F _tb_containers tb tbk tb_rpmfusion
+```