昨天花了一下午的时间，终于搞定了sed多行的问题，开心！

ok.sh:

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#sed "/^/[tool_path/][ /t]*/N;s/^/[tool_path/][ /t/n]*.*$//[tool_path/]/n//usr//bin//arm-linux-/" tools.cfg

TOOL=${TOOL:=/usr/bin/arm-linux-}

echo TOOL = $TOOL

TOOL1=`echo $TOOL |sed 's///////////g'`

sed '/^/[tool_path/][ /t]*/N;s/^/[tool_path/][ /t/n]*.*$//[tool_path/]/n'${TOOL1}'/' tools.cfg

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