commit to some level of style in variable naming

This is an ugly patch, and probably does more than I'd like it to. The
idea is that mkinitcpio adopts some sort of consistent style which I'm
actually happy with. I define 3 kinds of variables:

1) local variables: all lower case, and scoped within functions. Use
freely, as they're well contained.

2) global variables: these are known to mkinitcpio internally, but are
global in scope. They mainly carry runtime configuration and collected
data during the image generation process. These are always lower case,
but carry a leading underscore to denote that they're global.

3) "API" variables: also global in scope, but exist "outside" of
mkinitcpio -- either drawn in from the configuration file, or "exported"
to the install hooks. These are always all upper case. When introducing
new variables, extreme care must be taken to pick names that will not
conflict with the environment inherited by mkinitcpio.

A HACKING file is introduced with a similar description of the above,
and more.

Signed-off-by: Dave Reisner <dreisner@archlinux.org>

1 files changed, 9 insertions, 8 deletions

diff --git a/install/autodetect b/install/autodetect
index c0c7563..4f1e4bb 100644
--- a/install/autodetect
+++ b/install/autodetect
@@ -3,17 +3,17 @@
 build() {
     local -a md_devs
 
-    MODULE_FILE=$workdir/autodetect_modules
+    _f_autodetect_cache=$_d_workdir/autodetect_modules
 
     add_if_avail() {
         local resolved
 
         # treat this as an alias, since ext3 might be aliased to ext4.
         IFS=$'\n' read -rd '' -a resolved < \
-            <(modprobe -d "$MODULEROOT" -S "$KERNELVERSION" -R "$1" 2>/dev/null)
+            <(modprobe -d "$_optmoduleroot" -S "$KERNELVERSION" -R "$1" 2>/dev/null)
 
         if (( ${#resolved[*]} )); then
-            printf '%s\n' "${resolved[@]}" >>"$MODULE_FILE"
+            printf '%s\n' "${resolved[@]}" >>"$_f_autodetect_cache"
         fi
     }
 
@@ -22,7 +22,7 @@ build() {
         return 1
     fi
 
-    auto_modules >"$MODULE_FILE"
+    auto_modules >"$_f_autodetect_cache"
 
     # detect filesystem for root
     if rootfstype=$(findmnt -uno fstype '/'); then
@@ -40,12 +40,13 @@ build() {
     # scan for md raid devices
     md_devs=(/sys/class/block/md*/md/level)
     if [[ -e $md_devs ]]; then
-        (( !QUIET )) && plain "found %d mdadm arrays to scan" "${#md_devs[*]}"
-        awk '{ gsub(/raid[456]/, "raid456"); print; }' "${md_devs[@]}" | sort -u >>"$MODULE_FILE"
+        quiet "found %d mdadm arrays to scan" "${#md_devs[*]}"
+        awk '{ gsub(/raid[456]/, "raid456"); print; }' "${md_devs[@]}" |
+                sort -u >>"$_f_autodetect_cache"
     fi
 
-    if (( !QUIET )) && [[ -s $MODULE_FILE ]]; then
-        plain "caching %d modules" $(wc -l < "$MODULE_FILE")
+    if [[ -s $_f_autodetect_cache ]]; then
+        quiet "caching %d modules" $(wc -l < "$_f_autodetect_cache")
     fi
 }