m4=`which m4`
+# Check if the given program is installed. Returns 0 if it exists, 1
+# otherwise; so it can be used in if.
+installed() {
+ which $1 | grep -E '^/' > /dev/null
+}
+
+# Prints the current OS. Supported are Debian (debian), Gentoo (gentoo) and
+# Mac OS X (darwin) at the moment. If an unsupported OS is used an error is
+# printed.
+os() {
+ if [ -f /etc/debian_version ]; then
+ echo debian
+ elif [ -f /etc/gentoo-release ]; then
+ echo gentoo
+ elif [ x`uname` = xDarwin ]; then
+ echo darwin
+ else
+ echo unsupported OS! >&2
+ return 1
+ fi
+}
+
# Creates a symbolic link for file $1 in dirname of $2 with name of basenmae
# $2.
#
# to $1 with a warning at the beginning to not edit the generated file.
#
# All arguments (except the first which is the filename) are passed to m4.
+#
+# The following macros are defined: IF and FI. Example:
+# IF(OS, debian)
+# ...
+# FI
m4() {
# First argument is file name.
file=$1
# Process $1.m4 with m4 using the given options.
echo "m4(): generating '$file' from '$file.m4' with options '$*'"
- $m4 $* $file.m4 >> $file
+ # 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
unset file
}