Bash 实例：探讨 ebuild 系统

#!/usr/bin/env bashif [ $# -ne 2 ]then     
echo "Please specify ebuild file and unpack, compile or all"    
exit 1fisource /etc/ebuild.confif [ -z "$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}    e
cho "Unpacked ${DISTDIR}/${A}."    
#source is now correctly unpacked}user_compile() {    
#we're already in ${SRCDIR}    
if [ -e configure ]    
then        
#run configure script if it exists        
./configure --prefix=/usr    
fi        
#run make        
make $MAKEOPTS MAKE="make $MAKEOPTS"  } 
ebuild_compile() {    
if [ ! -d "${SRCDIR}" ]    
then        
echo "${SRCDIR} does not exist -- please unpack first."        
exit 1    
fi        
#make sure we're in the right directory      
cd ${SRCDIR}    
user_compile}export ORIGDIR=`pwd`export WORKDIR=${ORIGDIR}/workif [ -e "$1" ]
then     
source $1else    
echo "Ebuild file $1 not found."    
exit 1fiexport SRCDIR=${WORKDIR}/${P}case "${2}" in    
unpack)        
ebuild_unpack        
;;    
compile)        
ebuild_compile        
;;    
all)        
ebuild_unpack        
ebuild_compile        
;;    
*)        
echo "Please specify unpack, compile or all as the second arg"        
exit 1        
;;esac