Linux_Shell_学习笔记_20150604(5)

Shell编程复习

done

5 条件语句

shell里的条件语句主要是if语句、case语句

5.1 if语句

5.1.1 结构

if 表达式

then

[command]

elif 表达式

then

[command]

else

[command]

fi

5.1.2 举例

if test file1 -nt file2

then

echo "file1 is newer"

elif test file1 -ot file2

then

echo "file1 is older"

else

echo "file1 is as new as file2"

fi