Refactor: Lifted code outside of main function

It seemed like overkill to enclose the entire script in a function
just so readonly variables would work correctly.

xrsbd

@@ -1,9 +1,6 @@
 #!/bin/bash
 
-# Global readonly variables can't be shadowed by local variables so wrap
+USAGE="
-# our code in a function so we can declare all variables local
-main() {
-  local -r USAGE="
 USAGE: xrsbd [<mod_list>='cpu mem bl vol-amixer bat dt']
              [<pre>=' '] [<sep_l>='| '] [<sep_r>=' '] [<suf>=' ']
 
@@ -39,31 +36,24 @@ main() {
         from the output, so if you want them, simply include them in the
         prefix and suffix as shown here.
 
-                  xrsbd 'vol-amixer dt' '[<' '<' '>' '>]' &"
+                xrsbd 'vol-amixer dt' '[<' '<' '>' '>]' &
+"
 # Customizable configuration constants
-  local -r DEFAULT_MOD_LIST='cpu mem bl vol-amixer bat dt'
+DEFAULT_MOD_LIST='cpu mem bl vol-amixer bat dt'
-  local -r DEFAULT_PRE=' '
+DEFAULT_PRE=' '
-  local -r DEFAULT_SEP_L='| '
+DEFAULT_SEP_L='| '
-  local -r DEFAULT_SEP_R=' '
+DEFAULT_SEP_R=' '
-  local -r DEFAULT_SUF=' '
+DEFAULT_SUF=' '
 
-  local -r mod_list="${1-${DEFAULT_MOD_LIST}}"
+mod_list="${1-${DEFAULT_MOD_LIST}}"
-  local -r pre="${2-${DEFAULT_PRE}}"
+pre="${2-${DEFAULT_PRE}}"
-  local -r sep_l="${3-${DEFAULT_SEP_L}}"
+sep_l="${3-${DEFAULT_SEP_L}}"
-  local -r sep_r="${4-${DEFAULT_SEP_R}}"
+sep_r="${4-${DEFAULT_SEP_R}}"
-  local -r suf="${5-${DEFAULT_SUF}}"
+suf="${5-${DEFAULT_SUF}}"
 
-  local -r MOD_DIR="$(dirname "$0")"/module
+MOD_DIR="$(dirname "$0")"/module
-  local -r ACTION_DIR=/tmp/xrsb-action
+ACTION_DIR=/tmp/xrsb-action
-  local -i ACTION_DIR_LEN=${#ACTION_DIR}
+ACTION_DIR_LEN=${#ACTION_DIR}
-
-  # Cache module values so we can reuse them without recomputing them
-  local -A stat_cache
-  # Since stat_cache is hash ordered, maintain the display order (as defined
-  # by mod_list) of the keys so we can loop over the cache in display order
-  # when generating the full status
-  local -a stat_cache_ordered_mods mods
-  local mod mod_file
 
 # Map the module file name to the module function
 mod_to_fn() {
@@ -72,12 +62,13 @@ main() {
 
 # Check if the user needs help
 if [[ "${mod_list}" =~ ^(-h|-(-)?help)$ ]]; then
-    printf '%s\n' "${USAGE}" 1>&2
+  printf '%s' "${USAGE}" 1>&2
   exit 0
 fi
 
-  # For each module in the list, if the module file exists then source it, add
+# For each module in the list, if the module file exists then source it,
-  # its name to the ordered array, and call its function and cache the value
+# add its name to the ordered array, and call its function and cache the value
+declare -A stat_cache
 IFS=', ' read -r -a mods <<< "${mod_list}"
 for mod in "${mods[@]}"; do
   mod_file="${MOD_DIR}/${mod}"
@@ -97,8 +88,8 @@ main() {
       "${stat}" "${sep_l}" "${stat_cache[${mod}]}" "${sep_r}"
   done
 
-    # Trim the leading left separator and trailing right separator, and
+  # Trim the leading left separator and trailing right separator, and display
-    # display the status
+  # the status
   local -ri offset=${#sep_l}
   local -ri len=$((${#stat} - offset - ${#sep_r}))
   xsetroot -name "${pre}${stat:${offset}:${len}}${suf}"
@@ -107,8 +98,8 @@ main() {
 # Draw the initial status
 draw_status
 
-  # For each file in the action directory, remove the file, and if a module for
+# For each file in the action directory, remove the file, and if a module
-  # the action is cached, call the module function and update the cache. If
+# for the action is cached, call the module function and update the cache. If
 # any cache entries were updated, redraw the status.
 process_signal () {
   local -a action_paths
@@ -130,24 +121,20 @@ main() {
 trap process_signal SIGUSR1
 
 # Wait for signals efficiently. In a loop begin a long-running sleep command
-  # in the background, then wait on it. If we trap a signal before the wait
+# in the background, then wait on it. If we trap a signal before the wait is
-  # is over and sleep is still running, trap will call process_signal, then
+# over and sleep is still running, trap will call process_signal, then code
-  # code execution will resume at the line after the wait statement. So on
+# execution will resume at the line after the wait statement. So on that line
-  # that line we kill the (probably) still running sleep command so they
+# we kill the (probably) still running sleep command so they don't pile up,
-  # don't pile up, and loop to sleep and wait for the next signal. If we
+# and loop to sleep and wait for the next signal. If we don't trap a signal
-  # don't trap a signal during the long running sleep, then the wait ends,
+# during the long running sleep, then the wait ends, we try to kill the
-  # we try to kill the sleep command that has already exited, so it doesn't
+# sleep command that has already exited, so it doesn't matter, and loop to
-  # matter, and loop to sleep and wait again. Note that we don't make the
+# sleep and wait again. Note that we don't make the sleep too long because
-  # sleep too long because if the daemon is killed, the sleep will become
+# if the daemon is killed, the sleep will become an orphaned process until
-  # an orphaned process until the sleep period elapses.
+# the sleep period elapses.
-  local -i sleep_pid
 while :; do
   sleep 30m &
   sleep_pid="$!"
   wait "${sleep_pid}"
   kill "${sleep_pid}" 2>/dev/null
 done
-}
-
-main "$@"