Bash 实例：探讨 ebuild 系统

#!/usr/bin/env bashif [ $# -ne 2 ]then     
echo "Please specify two args - .ebuild file and unpack, compile or all"    
exit 1fiif [ -z "$DISTDIR" ]then     
# set DISTDIR to /usr/src/distfiles if not already set    
DISTDIR=/usr/src/distfilesfiexport DISTDIRebuild_unpack() {    
#make sure we're in the right directory     
cd ${ORIGDIR}        
if [ -d ${WORKDIR} ]    
then            
rm -rf ${WORKDIR}    
fi    
mkdir ${WORKDIR}    
cd ${WORKDIR}    
if [ ! -e ${DISTDIR}/${A} ]    
then        
echo "${DISTDIR}/${A} does not exist.  Please download first."        
exit 1    
fi        
tar xzf ${DISTDIR}/${A}    
echo "Unpacked ${DISTDIR}/${A}."    
#source is now correctly unpacked}ebuild_compile() {        
#make sure we're in the right directory    
cd ${SRCDIR}    
if [ ! -d "${SRCDIR}" ]    
then        
echo "${SRCDIR} does not exist -- please unpack first."        
exit 1        
fi    
./configure --prefix=/usr    
make     
}export ORIGDIR=`pwd`export WORKDIR=${ORIGDIR}/workif [ -e "$1" ]then     
source $1else    
echo "Ebuild file $1 not found."    
exit 1fiexport SRCDIR=${WORKDIR}/${P}case "${2}" in    
unpack)        e
build_unpack        
;;    
compile)        
ebuild_compile        
;;    
all)        
ebuild_unpack        
ebuild_compile        
;;    
*)        
echo "Please specify unpack, compile or all as the second arg"        
exit 1        
;;esac

ebuild_compile() {    
#make sure we're in the right directory      
if [ ! -d "${SRCDIR}" ]    
then        
ebuild_unpack        
fi    
cd ${SRCDIR}    
./configure --prefix=/usr    
make     
}