使用脚本编辑 android build.prop

Question

我正在尝试创建一个脚本来"自动"修改build.prop文件。我希望脚本检查我定义的条目，并且：1.如果它们不存在，请添加它们2.如果它们确实存在，请检查该值，如果它与我定义的不匹配，请修改它。

我创建了一个脚本。它运行但不输出任何内容，不更改 build.prop

我已经附上了脚本。正确吗？

#!/system/bin/sh 
# Definitions 
file=/system/build.prop 
tmpf=/system.buildprop.bak
line_list="wifi.supplicant_scan_interval=120 ro.sf.lcd_density=480" 
# Function to get args as needed for loop
getargs() {
par=$1
line=`echo $par |cut -d"=" -f1`
arg=`echo $par |cut -d"=" -f2`
} 
# Loop to make all changes in line_list 
for x in $line_lst; do 
# Get all needed arguments 
getargs $x 
# Write this change to a tmp file to check on it
oldarg=`grep $line $file |cut -d"=" -f2`
sed "s/$line=.*/$line=${arg}/g" $file > $tmpf
# Check if the change was made
chknewarg=`grep $line $tmpf |cut -d"=" -f2`
if [ "$chknewarg" = "$arg" ]; then
cp $tmpf $file
if [ -f $tmpf ]; then
rm $tmpf
fi
echo "File edited"
else
if [ -f $tmpf ]; then
rm $tmpf
fi
echo "Expected $arg, got $chknewarg instead"
exit 1
fi
# If it doesn't exist at all append it to the file
chkexists=`grep -c $line $file`
if [ $chkexists -eq 0 ]; then
echo "$x" >> $file
fi
done
exit 0

Answer 1

我玩得更多，从根本上改变了剧本。

#/system/bin/sh
 mount -o remount,rw /system
FILE=/system/build.prop
TMPFILE=$FILE.tmp
line1=wifi.supplicant_scan_interval
line2=ro.sf.lcd_density
line3=ro.media.enc.jpeg.quality
line1Arg=120
line2Arg=390
line3Arg=100
lineNum=
prop=$line1     
arg=$line1Arg   
if grep -Fq $prop $FILE ; then  
lineNum=`sed -n "/${prop}/=" $FILE`   
echo $lineNum
sed -i "${lineNum} c${prop}=${arg}" $FILE   
else
echo "$prop does not exist in build.prop"   
echo "appending to end of build.prop"
echo $prop=$arg >> $FILE
fi
prop=$line2     
arg=$line2Arg     
if grep -Fq $prop $FILE ; then  
lineNum=`sed -n "/${prop}/=" $FILE`    
echo $lineNum
sed -i "${lineNum} c${prop}=${arg}" $FILE    
else
echo "$prop does not exist in build.prop"   
echo "appending to end of build.prop"
echo $prop=$arg >> $FILE
fi
prop=$line3     
arg=$line3Arg     
if grep -Fq $prop $FILE ; then  
lineNum=`sed -n "/${prop}/=" $FILE`    
echo $lineNum
sed -i "${lineNum} c${prop}=${arg}" $FILE    
else
echo "$prop does not exist in build.prop"   
echo "appending to end of build.prop"
echo $prop=$arg >> $FILE
fi
mount -o remount,r /system

但是我收到"挂载：无效参数"错误？

此外，如何循环遍历 line 和 lineArg 变量来竞争操作？