epm pack: add create_file() and use it

pack.d/common.sh

@@ -96,6 +96,7 @@ return_tar()
     exit 0
 }
 
+# really like install -D src dst
 install_file()
 {
     local src="$1"
@@ -105,5 +106,14 @@ install_file()
     cp "$src" "$dest" || return
 }
 
+# Create target file from file
+# Usage: echo "text" | create_file file
+create_file()
+{
+    local t="$1"
+    install_file /dev/stdin $t
+}
+
+
 # set PRODUCT by pack.d script name
 [ -n "$PRODUCT" ] || PRODUCT="$(basename $0 .sh)"

pack.d/postman.sh

@@ -11,18 +11,17 @@ BASENAME=$(basename $TAR .tar.gz)
 
 ln -s $TAR $BASENAME.tar.gz
 erc unpack $BASENAME.tar.gz || fatal
+
 mkdir -p opt
-mkdir -p usr/share/pixmaps
 mv Postman/app opt/postman
 
-VERSION=$(cat "opt/postman/resources/app/package.json" | epm --inscript tool json -b | grep version | awk 'gsub(/"/, "", $2) {print $2}')
+VERSION=$(cat "opt/postman/resources/app/package.json" | epm --inscript tool json -b | grep version | awk 'gsub(/"/, "", $2) {print $2}') #'
 [ -n "$VERSION" ] || fatal "Can't get package version"
 
-cp opt/postman/resources/app/assets/icon.png usr/share/pixmaps/postman.png
+install_file opt/postman/resources/app/assets/icon.png usr/share/pixmaps/postman.png
 
 # create desktop file
-mkdir -p usr/share/applications/
-cat <<EOF > usr/share/applications/$PRODUCT.desktop
+cat <<EOF | create_file usr/share/applications/$PRODUCT.desktop
 [Desktop Entry]
 Version=1.0
 Type=Application

pack.d/sidequest.sh

@@ -15,8 +15,6 @@ ln -s $TAR $BASENAME.tar.xz
 erc unpack $BASENAME.tar.xz || fatal
 
 mkdir -p opt
-mkdir -p usr/share/applications/
-
 mv $BASENAME* opt/sidequest
 
 for res in 16x16 24x24 32x32 48x48 64x64 128x128 256x256 512x512 1024x1024; do
@@ -25,7 +23,7 @@ for res in 16x16 24x24 32x32 48x48 64x64 128x128 256x256 512x512 1024x1024; do
 done
 
 # create desktop file
-cat <<EOF > usr/share/applications/$PRODUCT.desktop
+cat <<EOF | create_file usr/share/applications/$PRODUCT.desktop
 [Desktop Entry]
 Version=1.0
 Type=Application