lib.sh: Add generate() which replaces m4().

[config/dotfiles.git] / lib.sh

diff --git a/lib.sh b/lib.sh
index 6cd3d2f8d79adf7cb662ae6347fd394c8966e172..fbef907d330bd62aec6bf67a5d0b4c237c267159 100644 (file)
--- a/lib.sh
+++ b/lib.sh
@@ -7,9 +7,6 @@
 # options supported by zsh or GNU ls.
 unset LS_COLORS
 
-# Get path to m4 because it's later redefined as function.
-m4=`which m4`
-
 
 # Check if the given program is installed. Returns 0 if it exists, 1
 # otherwise; so it can be used in if.
@@ -73,40 +70,56 @@ link() {
 }
 
 # Write a warning to $1 to make clear it should not be modified. $2 is the
-# source for the generated file.
-setup_warning() {
+# source for the generated file. Also print a message to stdout that the file
+# $1 was generated from $2 using the command $3.
+warning() {
     echo "###################################" > $1
     echo "# WARNING! DO NOT EDIT THIS FILE! #" >> $1
     echo "###################################" >> $1
     echo >> $1
     echo "# It was generated from $2 on `date`." >> $1
     echo >> $1
+
+    # Write message to stdout.
+    echo "$3: generating '$1' from '$2'"
 }
 
-# m4 wrapper which uses $1.m4 as template file, feeds it to m4 and writes it
-# to $1 with a warning at the beginning to not edit the generated file.
+# Generate a file using several methods. A warning is automatically added to
+# the created file and a message printed to stdout through warning().
 #
-# All arguments (except the first which is the filename) are passed to m4.
+# The following commands are possible; the file extension for the source file
+# in brackets.
 #
-# The following macros are defined: IF and FI. Example:
-#     IF(OS, debian)
-#         ...
-#     FI
-m4() {
-    # First argument is file name.
-    file=$1
+# - m4  (.m4): pipe $2.m4 through m4 then write it to $2
+# - awk (.in): pipe $2.in through awk then write it to $2
+# - cat ($3):  copy $2$3 to $2
+generate() {
+    # Get command and target file.
+    command="$1"
+    file="$2"
+    # Remove arguments from list.
+    shift
     shift
 
-    # Write a warning to the generated file to not edit it.
-    setup_warning $file $file.m4
+    # Set extension for the used commands. When cat is used $3 is used as
+    # extension.
+    if [ x"$command" = xm4 ]; then
+        extension=.m4
+    elif [ x"$command" = xawk ]; then
+        extension=.in
+    elif [ x"$command" = xcat ]; then
+        extension="$1" # is $3 in reality, $1 because of shifting
+        shift
+    # Print a warning and exit if an unsupported command is used.
+    else
+        echo "generate(): command '$command' not supported!" >&2
+        exit 1
+    fi
 
-    # Process $1.m4 with m4 using the given options.
-    echo "m4(): generating '$file' from '$file.m4' with options '$*'"
-    # Add useful macros.
-    (echo "define(\`IF', \`ifelse(\`\$1', \`\$2',dnl')dnl
-define(\`FI', \`)dnl')dnl";
-        # Run the file (and the default macros) through m4.
-        cat $file.m4) | $m4 "$@" >> $file
+    # Add warning to file and write a message to stdout.
+    warning "$file" "$file$extension" $command
+    # Generate $file from $file$extension using the given command.
+    cat "$file$extension" | $command "$@" >> "$file"
 
-    unset file
+    unset command file
 }