add -t option to specify alternate build directory

This requires some refactoring of how we handle TMPDIR declaration and
creation, as well as protecting the way we do cleanup so that we don't
error out when cleanup is called prior to TMPDIR being declared.

We also add a shortcut to the build root based on the TMPDIR for
convenience.

Signed-off-by: Dave Reisner <d@falconindy.com>

3 files changed, 31 insertions, 16 deletions

diff --git a/functions b/functions
index a4f6c0c..dbbcb3c 100644
--- a/functions
+++ b/functions
@@ -132,9 +132,9 @@ add_dir() {
     # Add a directory to the initcpio image.
     #   $1: absolute path of directory on image
 
-    if [[ ! -e "$TMPDIR/root/$1" ]]; then
+    if [[ ! -e "$BUILDROOT/$1" ]]; then
         (( QUIET )) || plain "adding dir: %s" "$1"
-        command install -dm755 "$TMPDIR/root/$1"
+        command install -dm755 "$BUILDROOT/$1"
     fi
 }
 
@@ -148,7 +148,7 @@ add_symlink() {
     add_dir $(get_dirname "$file")
     if [[ ! -e "$TMPDIR/root/$dest" ]]; then
         (( QUIET )) || plain "adding symlink: $file -> $dest"
-        ln -s "$dest" "$TMPDIR/root/$file"
+        ln -s "$dest" "$BUILDROOT/$file"
     fi
 }
 
@@ -170,9 +170,9 @@ add_file() {
             return
         fi
 
-        if [[ ! -e "$TMPDIR/root/$dest" ]]; then
+        if [[ ! -e "$BUILDROOT/$dest" ]]; then
             (( QUIET )) || plain "adding file: %s" "$dest"
-            command install -Dm$(stat -c '%a' "$file") "$file" "$TMPDIR/root/$dest"
+            command install -Dm$(stat -c '%a' "$file") "$file" "$BUILDROOT/$dest"
         fi
     else
         error "file '$file' does not exist"
diff --git a/mkinitcpio b/mkinitcpio
index 1f4792c..53326f0 100755
--- a/mkinitcpio
+++ b/mkinitcpio
@@ -13,7 +13,6 @@
 shopt -s extglob
 
 # Settings
-TMPDIR=$(mktemp -d /tmp/mkinitcpio.XXXXXX)
 MESSAGEFILE=$TMPDIR/message
 KERNELVERSION=$(uname -r)
 FUNCTIONS=functions
@@ -23,7 +22,7 @@ INSTDIR=install
 PRESETDIR=mkinitcpio.d
 COMPRESSION=gzip
 
-declare BASEDIR MODULE_FILE SAVELIST GENIMG PRESET MESSAGE COMPRESSION_OPTIONS
+declare TMPDIR BASEDIR MODULE_FILE GENIMG PRESET MESSAGE COMPRESSION_OPTIONS BUILDROOT
 declare NC= BOLD= BLUE= GREEN= RED= YELLOW=
 declare -i QUIET=1 SHOW_AUTOMODS=0 SAVELIST=0 COLOR=1
 declare -a SKIPHOOKS ADDED_MODULES
@@ -49,6 +48,7 @@ usage ()
     echo "  -m MESSAGE       Print MESSAGE before passing control to init."
     echo "  -n               Disable colorized output messages."
     echo "  -S SKIPHOOKS     Skip SKIPHOOKS (comma-separated) when building the image."
+    echo "  -t TMPDIR        Use TMPDIR as the temporary build directory."
     echo "  -v               Verbose output. Default: no"
     echo "  -M               Display modules found via autodetection." 
     echo "  -L               List all available hooks." 
@@ -60,10 +60,12 @@ usage ()
 
 cleanup ()
 {
-    if (( SAVELIST )); then
-        msg "build directory saved in %s" "$TMPDIR"
-    else
-        rm -rf ${TMPDIR}
+    if [[ $TMPDIR ]]; then
+        if (( $SAVELIST )); then
+            msg "build directory saved in %s" "$TMPDIR"
+        else
+            rm -rf "$TMPDIR"
+        fi
     fi
 }
 
@@ -95,7 +97,7 @@ get_kernver() {
 
 trap sighandler TERM INT
 
-while getopts ':c:k:sb:g:p:m:nvH:LMhS:' arg; do
+while getopts ':c:k:sb:g:p:m:nvH:LMhS:t:' arg; do
     case "${arg}" in
         c) CONFIG="${OPTARG}" ;;
         k) optkver=$OPTARG ;;
@@ -115,14 +117,13 @@ while getopts ':c:k:sb:g:p:m:nvH:LMhS:' arg; do
         H) . "${INSTDIR}/${OPTARG}";
            msg "Help for hook '${OPTARG}'"
            help
-           cleanup
            exit 0 ;;
         L) msg "Available hooks"
            cd "$INSTDIR" >/dev/null
            printf '   %s\n' * | column -c$(tput cols)
-           cleanup
            exit 0 ;;
         M) SHOW_AUTOMODS=1 ;;
+        t) TMPDIR=$OPTARG ;;
         h|?) usage ;;
         :) echo "${OPTARG} requires a value..."; usage ;;
     esac
@@ -155,6 +156,17 @@ if [[ $optkver ]]; then
     fi
 fi
 
+if [[ $TMPDIR ]]; then
+    if [[ ! -d $TMPDIR ]]; then
+        error "'$TMPDIR' does not exist or is not a directory"
+        unset TMPDIR
+        cleanup
+        exit 1
+    fi
+fi
+TMPDIR=$(mktemp -d "${TMPDIR:-/tmp}/mkinitcpio.XXXXXX")
+declare BUILDROOT=$TMPDIR/root
+
 # use preset $PRESET
 if [[ $PRESET ]]; then
     if [[ -f "$PRESETDIR/$PRESET.preset" ]]; then
@@ -285,7 +297,7 @@ done
 if (( ${#ADDED_MODULES[*]} )); then
     msg "Generating module dependencies"
     /sbin/depmod -b "${TMPDIR}/root" "${KERNELVERSION}"
-    rm "$TMPDIR/root/lib/modules/$KERNELVERSION"/modules.!(dep.bin|alias.bin|symbols.bin)
+    rm "$BUILDROOT/lib/modules/$KERNELVERSION"/modules.!(dep.bin|alias.bin|symbols.bin)
 fi
 
 declare -i status=0
@@ -294,7 +306,7 @@ if [[ "${GENIMG}" ]]; then
     msg "Creating $COMPRESSION initcpio image: %s" "$GENIMG"
     [[ "$COMPRESSION" = xz ]] && COMPRESSION_OPTIONS+=" --check=crc32"
 
-    pushd "$TMPDIR/root" >/dev/null
+    pushd "$BUILDROOT" >/dev/null
     find . -print0 | bsdcpio -0oH newc | $COMPRESSION $COMPRESSION_OPTIONS > "$IMGPATH"
     pipesave=("${PIPESTATUS[@]}") # save immediately
     popd >/dev/null
diff --git a/mkinitcpio.5.txt b/mkinitcpio.5.txt
index 1c96b8e..66bab68 100644
--- a/mkinitcpio.5.txt
+++ b/mkinitcpio.5.txt
@@ -42,6 +42,9 @@ Options
 *-S* 'hooks'::
 	Skip 'hooks' when generating the image. Several hooks should be comma-separated.
 
+*-t* 'tmpdir'::
+	Use 'tmpdir' as the temporary build directory instead of /tmp. 'tmpdir' must exist.
+
 *-v*::
 	Verbose output. Outputs more information about what's happening during creation of the ramdisk.